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1. NE UIS UE Major adjustments and servicing HON EEG 3 SECTION 1 L 151 L 152 L 153 LM 152 Adjustment for wear minor Pus ON RO X MERGE Row Eus x Major adjustments and servicing dS Page 8 9 15 15 11 12 7 8 14 15 9 10 10 11 17 N Ww wN Ww WH 2 3 4 2 3 4 Donated by John amp Susan Hansen For Personal Use Only L LINE MOTOR TRUCK SERVICE MANUAL BRAKE SHOE ADJUSTMENTS AND SERVICING CONTINUED SECTION J L 160 L 161 L 162 L 163 L 164 L 165 LC 160 LC 161 LC 162 L 170 L 171 L 172 BRAKE SYSTEM Index Page 3 L 173 L 174 L 175 LF 170 LF 171 LF 172 FRONT BRAKE 12 1 8 x2 1 4 TYPE L 180 L 181 L 182 L 183 L 184 L 185 LC 180 LC 181 LC 182 FRONT BRAKE 13 x 2 1 2 TYPE L 190 L 191 L 192 L 193 L 194 L 195 LF 190 LF 191 LF 192 LC 190 L C 191 L C 192 L 200 L 201 L 202 L 204 L 205 LC 200 LC 201 LC 202 FRONT BRAKE 15 x2 1 4 TYPE Page Bleeding the hydraulic brake 5 5 TET 5 Brake ndjustmoQ nbs code 4 4x oe OEE St RDS Ew XO 4 5 Brake component parts TT S 20 5 8 WE OE E POR ESO A EC A RC N 2 Removal of brake shoes Terre Z ww TTC 3 Removal of wheel Cylinders 44 94 4 sz
2. M 5 Air pressure gauge s z s t o m LP 14 Brake chamber Bendix Westinghouse Lees ence es ee ee ee ee eee 12 13 Brake chamber piston type Midland TTE 13 14 Brake valve w w q x 4 ox cm ROCA EO eo Woo Oe e A xov 5 6 Brake valve hand operated TP IT 6 4 Cut out COCKS s w s UP UK oW E raum ed k E OR 14 Double check 1 5 oe 4 x Tr 8 Continued PRINTED IN UNITED STATES OF AMERICA Donated by John amp Susan Hansen For Personal Use Only BRAKE SYSTEM Index L LINE MOTOR TRUCK SERVICE MANUAL Page 2 BRAKE GROUP CONTINUED AIR BRAKE SYSTEM SECTION C CONT D Drain cocks jx lk KU bas deo dc 9 Q Q d ER Governor Lype Oel 4E ACE AO p XR Uw E S S Hose and hose connectionS 1 s S s s e e s e s n 09 9 0 ow k Hose coupling and dummy couplings TT Low pressure indicator sas s s s e s s e s e e TIT a wee Quick release valve gh a p 2 TT Relay valve s s s es e o e 9 9 9 5 e o RESETVOITS 6 vy CRE dX HEE HER wwe
3. FRONT BRAKE 13 x 2 1 4 TYPE F FRONT BRAKE 15 x 2 1 4 TYPE Brake shoe hold down washer 090 Backing plate Lining Brake shoe a Brake shoe adjusting cam y EZ 4 EE ME 9 orm tes TCT ITT LTTE TE emus T rnm Wheel cvlinder Retracting spring A 23198 Fig 2 Front Brake Internal View Type Donated by John amp Susan Hansen For Personal Use Only BRAKES s L LINE MOTOR TRUCK SERVICE MANUAL Section J Page 2 14 WU 15 423 20 19 18 09 24 30 LE 26 23 25 27 29 1 22913 Fig 3 Front Brake Exploded View F Item Item No DESCRIPTION No DESCRIPTION Piston assembly 1 assembly brake backing 2 Stud adjusting cam amp shoe guide Boot 9 Washer plain cam stud Tube assembly connector wheel 4 Spring adjusting cam cylinder 5 Cam shoe adjusting Bolt fitting inlet brake line to cylinder 6 Washer spring anti rattle shoe guide amp tube 7 Shoe amp lining assembly Gasket bolt 8 Shoe Fitting inlet fluid connector tube 9 Lining Gasket fitting 10 Rivet lining Bolt fitting inlet connector tube to 11 Washer plain shoe guide cylinder 12 Washer shoe guide stud Screw anchor cylinder 13 Spring retracting brake shoe Lockwasher cylinder anchor screw
4. Area Working Work mum oquare Stroke ing Stroke Inches Stroke 1 3 8 1 3 4 3 4 2 4 1 3 4 2 1 4 1 1 4 5 8 1 3 8 1 3 4 3 3 4 2 1 2 6 15 16 9 3 16 8 1 16 Q zj EJ Q J gt Preventive Maintenance Every Month or After Each 2 000 Miles Check travel of brake chamber push rods and adjust brakes if necessary Push travel should be kept at the minimum without brakes dragging Excessive travel shortens the serv ice life of brake chamber diaphragms and also results in slow braking response Every Year or After Each 50 000 Miles Disassemble brake chambers and clean all parts Install new diaphragms When replac ing release springs be sure to use the correct spring otherwise uneven braking will result Leakage Tests l With brakes fully applied coat the brake chamber bolting flanges holding the dia phragm in place with soapsuds to check for leakage No leakage is permissible If leakage is found tighten flange bolts All flange bolts must tightened evenly but only sufficiently to prevent leakage otherwise the diaphragm will be distorted and premature failure will result 2 With brakes fully applied check for leakage through the diaphragm by coating the clearance hole around the push rod and the drain hole in the non pressure plate with soap suds No leakage is permissible If leakage is found the diaphragm must be replaced PRINTED IN UNITED STATES
5. Bleeder valve A 22728 Fig 3 Typical Wheel Cylinder Double piston type Repairs to Master and Wheel Cylinders It is possible to rehone the majority of cyl inders and place them in good working condition however this requires the use of up to date honing equipment and plug gauges A cylinder hone kit is available under number SE 1679 and a set of plug gauges under number 5 1000 If this equipment is not available we recom mend that the unit be taken to the nearest Wagner Service Branch or Authorized Service Station for repairing Cylinders and parts must not be washed in gasoline kerosene or oil Use high grade denatured alcohol Care Keep all lubricant and brake fluid away from brake linings Inspect master cylinder at the time of making brake adjustments for correct fluid level Fluid should be within 3 8 from bottom of filler neck Do not fill supply reservoir to top of filler neck Caution When removing supply reser voir filler cap extreme care must be used to prevent dirt or moisture from entering master cylinder Brake Pedal Adjustment When brake control system is in release position foot brake pedal should have 1 4 free travel Fig 4 before the pressure stroke starts This free travelis required to prevent blocking of compensating port in master cylinder Brakes will drag if compensating port becomes blocked due to pressure building up in the system Shorten pedal push rod to allo
6. 5 5 THydro vac Check 644 u 3 GR EO Qa ER EX e 6 7 LIDaSirallONS ec e x o 9 WU Q o W R es E Rs ee PP s 6 a we oe 1 23 Lubrication Cc de ew oe ela ee 4 Vacuum SETVICE sansara vamas 99 30 444 9 5 Vacuum line oil bath air cleaner 5 SECTION C AIR BRAKE SYSTEM Air brake equipment aa ee FORCE Ue Rd IECIT 1 2 Operation a 24 6 9 9 ox Pr is 2 Release ee W CEES EEK GOR Q Application ss s ponire aink 2 Instructions eee SC oe Crue eee wae ee 8 EP 2 3 Preventive Maintenance and Trouble Shooting Air leakage test ee TTL TT 4 Inspection S SP Q QUR S E 4 Operating tests 9 TIT KG ho wee Paseo mk 4 DETVICE V ES Oe eS eee re E Wil S OS ee Tr 3 4 Trouble shooting ESE sl w
7. CAP NUT ees UNLOADING pin a MER zo A P P VALVE SPRING p m b ers a ee DISCHARGE PORT A 9349 Fig 2 Adjusting Compressor Unloading Valve Clearance Every Six Months or After Each 10 000 Miles a the compressor is lubricated from the engine clean oil supply line to compressor b Check compressor unloading valve clearance and adjust if necessary Fig 2 Clearance must be 0 010 inch minimum to 0 015 inch maximum To adjust clearance loosen lock nuts and turn adjusting screws until proper clearance is obtained Then tighten lock nuts Clearance can be checked only when governor is cut in compressor not unloaded Check unloading valve lever for binding c If compressor is the self lubricated type service crankcase breather Washbreath erin cleaning solvent INTERNATIONAL d Remove compressor discharge valve cap nuts and check for presence of excessive carbon If excessive carbon is found clean the compressor cylinder head also check com pressor discharge line for carbon and clean or replace the discharge line if necessary Inspection l sure compressor air strainer is clean and properly installed Also sure blanking covers and gaskets are installed on all strainer openings notbeing usedin the com pressor intake manifold 2 With compressor running check for noisy operation and oil or water leaks 3 Check unloader valve clearance
8. s s s s e s e s n 5 Replacement of brake shoes eee ee ee q Q Tr 5 Replacement wheel cylinders kx d wie Q 5 Service specifications Tr 6 Wheel cylinder assembly POGUES 509 And T 4 Wheel cylinder disassembly s a s e e s s s s s e s s e s s sa 4 PARKING ADJUSTMENTS SECTION LM 120 L 130 L 150 LM 150 L 160 LC 160 L 170 LF 170 Series Trucks 1 L 180 LC s180 Series Trucks 44 4x 4 ox Row SK O43 S wo 9 OR w TT 1 L 190 LF 190 Series Trucks ine 200 L 201 L 202 L 204 Trucks Ei 2 2 L 205 L 210 L 211 L 212 LF 210 LF 211 LF 212 LF 220 LF 221 LF 222 Trucks v2oOIH3HY S31yiS AFLINN NI 93 TRUCK MODEL Brake PVRS d c OA es Brake Size Standard Front 44 9549235 Brake Size Increased Capacity Front Same as Standard Front Front Wheel Cylinder Size Standard Front Rear s 94 eee amp Wheel Cylinder Size Increased Capacity Front Same as Standard Number of Wheel Cylinders Standard POW 4 44 es pci Number of Wheel Cylinders Increased Capacity Front Same as Standard Master Cylinder Size Bore and Stroke wx ee Hydrovac Standard or Optional Model No Bendix SOTICS aa
9. small flashlight is helpful when inspecting the interior If damage or corrosion is found that would weaken the reservoir replace the reser voir 3 Moisture taken in with the air through the compressor inlet valves collects in the reservoirs and necessitates draining the res ervoirs daily in cold weather and every week in warm weatherby opening the drain cock located on the bottom Be sure to close the drain cocks after all moisture has been removed Safety valve Reservoir A 22835 Safety Valve Fig 18 Illustrates Reservoir and Drain Cock DRAIN COCKS Description 1 Drain cocks have a brass body fitted with a tapered brass key The drain cock is open when the handle is parallel to the body and closed when the handleis at right angles to the body Drain cocks are installed in the bot tom of each reservoir in the air brake system to provide convenient means of draining the condensation which normally collects in the reservoirs PRINTED IN UNITED STATES OF AMERICA Donated by John amp Susan Hansen For Personal Use Only L LINE MOTOR TRUCK SERVICE MANUAL BRAKES AIR Section C Page 15 2 Always open a drain cock by hand Never strike the handle with hammer or any other instrument as the cock would be damaged and leakage would develop Testing 1 With the air brake system charged test with soapsuds for leakage past the key Also check for leakage through the body by coating the o
10. we TETTETETT 98196 4 440 x 3 SUS a N OR Slack adjuster T du S a cu Stop light switch PTT Tubing p e e e e Ld 4 BRAKE SHOE ADJUSTMENTS AND SERVICING SECTION D 110 L 111 L 112 L 120 L 121 L 122 Adjustment for wear minor X u vu s lt tude 3x E Major adjustments and servicing CEPIT Parking brake cable adjustment wq 6 x wo ws SECTION E LM 120 LM 121 LM 122 Adjustment for wear minor i939 o X a 9 eH RO Major adjustments and servicing 6 45 e w e w w X x Eo d wow ds SECTION L 130 L 131 L 132 Adjustment for wear minor ee eee TT Major adjustments and servicing C SECTION LB 140 Adjustment for wear 2 8 d ws Tr Major adjustments and servicing amp o ud S Roe cd Parking brake cable adjustment amp W SECTION H 11 150 LM 150 LM 151 Adjustment for wear minor
11. x49 9 9 4 3 Cylinder Diameter Single or Tandem Piston 2 Single 4 Donated by John amp Susan Hansen For Personal Use Only HYDRAULIC BRAKE SPECIFICATIONS L 110 L 120 L 130 L 151 L 111 Li 121 L 131 LB 140 L 150 L 152 LM 150 L 112 L 122 L 132 L 153 LM 151 Hydraulic Hydraulic Hydraulic Hydraulic Hydraulic Hydraulic Hydraulic MERERETUR 12x1 3 4x3 16 12 2 3 16 12x2x3 16 14x2 1 4x1 4 14x2 1 4x1 4 12 1 8x2x1 4 14 1 8x3x3 8 12 1 8x2x1 4 12 1 8x2x1 4 14 1 8x3x3 8 9 Single Single 3 n gt O TM T I w coo I 1 8 1 1 4 1 3 8 1 TVWOANVW AONUL 1 t 1 1 8x1 7 16 Barrel 1 1 1 8 1 7 16 Barrel 2 Barrel Optional 374000 en 6 3 4 Single f s s s s EN x J g adeg f w gt 14 2 1 4 1 4 1 1 8x1 7 16 suotje2gri edg z m m gt gt INXILSAS Donated by John amp Susan Hansen For Personal Use Only HYDRAULIC BRAKE SPECIFICATIONS Continued TRUCK MODEL LM 152 L 174 Brake 45 292449 Hydraulic Hydraulic Hydraulic Hydraulic Hydraulic Hydraulic Brake Size Sta
12. Donated by John amp Susan Hansen For Personal Use Only Thoroughly clean star wheel adjusting screws pivot nuts hold down pins springs and cups Apply small amount of suitable lubricant comparable to Lubriplate to threaded end of the adjusting screw and to contact points on the shoe webs PERFORM THE FOLLOWING OPER ATIONS AT EACH FRONT WHEEL SEE FIGS 1 AND 2 When installing new brake shoes lay the shoes out in pairs according to their position on the truck The upper secondary shoe is the shoe with the longer lining Thread the star wheel adjusting screw into the pivot nut to the limit of the threads and assemble star wheel adjusting screw and spring to the adjustment end of the shoes NOTE Always assemble pivot nut on the right hand shoe as viewed from the ad justing screw end of the shoes regardless of whether the brake shoes are for left or right side of truck Assemble shoe links to wheel cylinder and and guide forked end of shoe links over anchor end of shoe webs Attach brake shoes to backing plates with shoe hold down pins springs and cups Attach retracting springs to shoes and anchor pin If springs show signs of having been overstressed they should be replaced Install brake drums For lubrication and adjustment of front wheel bearings see wheel section NOTE It may be essary to change the position of the shoe eccentric when assembling drum over shoes NOTE DO NOT LOO
13. 14 Wheel cylinder assembly Washer plain cylinder anchor screw 15 Body wheel cylinder Screw fastening wheel cylinder 16 Spring Lockwasher fastening screw 17 Filler piston cup Valve bleeder cylinder 18 Cup piston Rotation A 23448 Fig 4 Brake Adjustment Type F Brake MAINTENANCE AND ADJUSTMENT WAGNER SELF CENTERING TYPE F BRAKES See Figs 1 2 and 3 This Wagner self centering Hi Tork Brake Type is Floating Shoe type which has two identical shoes 7 Fig 3 arranged on the backing plate 1 so that their toes are diagonally opposite Two single end wheel cylinders 14 are arranged so that one cylinder is mounted between each shoe toe and the op posite shoe heel The two wheel cylinder pistons 19 apply equal amounts of hydraulic force to each shoe toe Each cylinder body is shaped to provide an anchor block for the opposite shoe heel Each cylinder anchor block serves as a shoe stop and shoe centering point and provides the ful crum around which the shoe heel pivots when the brakes are applied Each shoe is adjusted by means of an ec centric cam 5 which contacts the underside of the shoe table Each cam is attached to the backing plate by cam and shoe guide stud 2 which protrudes through a slot in its shoe web and in conjunction with washers 11 and washers 12 also serves as a shoe hold down Two retracting springs 13 are connec
14. 15 Drum Diameter wg xx 4 FR 25 Brake 16 1 2 Drum Diameter 3 1 2 FR 2SD Brake 16 1 2 Drum Diameter 3 1 2 LINING THICKNESS Standard Lining FR 2 Brake 14 1 8 and 15 Drum Diameter 3 8 25 Brake 16 1 2 Drum Diameter 5 8 FR 2SD Brake 16 1 2 Drum Diameter 5 8 Donated by John amp Susan Hansen For Personal Use Only BRAKES ADJUSTMENTS L LINE MOTOR TRUCK SERVICE MANUAL Section L Page 1 HYDRAULIC BRAKES BRAKE SHOE ADJUSTMENTS AND SERVICING L 184 L 190 L 191 L 192 L 193 L 195 REAR BRAKES LC 190 LC 191 LC 192 16 x 4 LF 210 LF 211 LF 212 LF 220 LF 221 LF 222 TYPE REAR BRAKES 16 x 5 L 194 L 200 L 201 L 202 L 205 TYPE FR LC 200 LC 201 LC 202 Retracting spring Brake shoe guide Adjusting slot washer Bleeder valve Wheel cylinder Wheel cylinder Brake shoe Brake shoe Direction of drum rotation AL o lining Adjusting slot A 23196 Internal View External View Fig Rear Brake Type FR PRINTED IN UNITED STATES OF AMERICA Donated by John amp Susan Hansen For Personal Use Only INTERNATIONAL BRAKES Secus sa L LINE MOTOR TRUCK SERVICE MANUAL Section L Page 2 A 22909 po DESCRIPTION DESCRIPTION 1 Plate brake backing Cup piston 2 Shoe lining amp adjuster assembly Ring segment back up pi
15. 3 Screw adjusting Piston short 4 Wheel star adjusting Cup piston 5 Lockspring adjusting Protector segment cup piston 6 Shoe and lining assembly Boot assembly 7 Shoe Push rod 8 Lining Vaive bleeder 9 Rivet Cover wheel cylinder 10 shoe guide stud Bolt wheel cylinder 11 Washer shoe guide Lockwasher wheel cylinder bolt 12 spring sshoe guide Tube assembly connecting 13 Spring brake shoe retracting Fitting tube connecting 14 Wheel cylinder assembly Fitting tube connecting 15 Body wheel cylinder Bolt fitting tube connecting 16 Piston assembly long piston Washer fitting bolt 17 Piston long Washer fitting bolt 18 piston Cover adjusting slot Protector segment cup piston Donated by John amp Susan Hansen For Personal Use Only L LINE MOTOR TRUCK SERVICE MANUAL HYDRAULIC BRAKES BRAKE SHOE ADJUSTMENTS AND SERVICING L 210 L 211 FRONT BRAKES 16 1 2 x 3 1 2 TYPE FR 2S FIGS 3 and 4 LF 210 LF 211 LF 212 LF 220 LF 221 LF 222 Wheel cylinder cover Brake shoe linings Brake hose connection Retracting spring Bleeder valve NN O Brake adjusting O worm gears O O Bleeder valve Brake spider Wheel cylinder Dust shield Internal View A 23207 External View Fig 3 ES Front Brake Type 25 PRINTED IN UNITED STATES OF AMERICA BRAKES ADJU
16. A 22818 Fig 3 Exterior View of Third Series C Series Single 9 1 2 Diameter Guided Piston Hydrovacs No s 375278 and 375279 Control valve piston Atmosphere control Clamp bolt Bleeder valve Diaphragm line Vacuum valve Diaphragm return spring Piston return spring Atmospheric valve N Cylinder shell w N SA stud Piston guide TM Piston guide rod N sl nmm ni Atmosphere inlet from air cleaner Bleeder valve N ee V Nn NS D re TE 1 d L ai Residual check valve Outlet to wheel cylinders Slave cylinder t pr eur Vacuum piston Lubrication plug By pass valve Yoke by pass valve nlet from master cylinder Cylinder shell Vacuum inlet from vacuum source Push rod seals Inlet drawn out of position P End plate 125285 Fig 4 Sectional View of Third Series C Series Single 9 1 2 Diameter Guided Piston Hydrovacs No s 375278 and 375279 M INTERNATIONAL Donated by John amp Susan Hansen For Personal Use Only BRAKES L LINE MOTOR TRUCK SERVICE MANUAL 999 Section B Section B Page 3 Atmosphere inlet to fast application valve f from engine air Viren Center plate Bleeder valve Vacuum inlet gm TEN ON _ aad pi i mem lt t Bleeder va
17. LL ZI Cee Single Single Guided Single Guided These hydrovacs contain a residual pressure check valve and must be used with a master cylinder that does not have a residual pressure check valve Series 3 3 3 3 s s s Cylinder Diameter Single or Tandem Piston 7 229 WALSAS 1 m 125 gt P TIVANVW 2 NONUL YOLOW YDOIBRAWY JO 531715 O31LIND NI O31NIHd TRUCK MODEL Brake Type baer Brake Size Standard Front c Brake Size Increased As Front Same as Standard Front s 40 Front Front e Rear 9 gt Wheel Cylinder Size Increased Capacity Front Same as Standard Number of Wheel Cylinders Standard BOPOnEbgso G G XX x x Rear lt 4 6 x e 4 Number of Wheel Cylinders Increased Capacity Front Same as Standard Master Cylinder Size Bore and Stroke 4 44 m EOS ue Hydrovac Standard or Optional Model No Bendix DETICS amp a 4 S Cylinder Diameter Single or Tandem Piston gt e gt Q Donated by John amp Susan Hansen For Personal Use Only HYDRAULIC BRAKE SPECIFICATIONS Continued
18. TRUCK MODEL LC 201 E 9 LC 202 Uu rj lt Sanda Spel sea Brake Size Front 16 2 1 4 5 16 16 2 1 4 5 16 l x2 1 4x5 16 2999975999 eam emer Brake Chamber Front ih Location Back Plate Back Plate Back Plate lt T MUN K de eee 2 9 CEI exu 6308 pel eX Chamber Rear Location Axle Pad Axle Pad Axle Pad EI 5 debe I 59 l CO Sae 7 Slack Adjuster Length 3 3 8 4 5 T lt __ 72 0 oe Brake Valve Model D 1 D 1 D 1 E J gt Control Foot Pedal Foot Pedal vus a gt Air Reservoir Number Used 1 1 J T 33 Engine Belt m gt o zi VWOINSWY JO 531715 Q341NO NI G31NIHd Donated by John amp Susan Hansen For Personal Use Only AIR BRAKE SPECIFICATIONS Continued L 210 TRUCK MODEL L 204 L 211 Standard or Special Special Brake Size Frons 4 16x2 1 4x5 16 17 1 4x3x3 8 Rear T 16 1 2x7x3 4 16 1 2 7 3 4 Brake Chamber Front Location E s Back Plate Back Plate se se kw E A ee 6 3 16 6 15 16 Brake Chamber Rear Locatio
19. The anchors are free to rotate within their supports so that when the brake is applied the pin will turn with the shoe In addition the anchors are slotted to allow the shoe heel to slide inwardly or outwardly along the axle radius to center the shoe properly in relation to the drum Self centering of shoes when the vehicle is in backward motion is accomplished by rounded shoe toes which pivot on the adjusting screws The shoes on these brakes are floating shoes Each shoe is held in position by shoe guide pin washer shoe guide spring C clip and two shoe return springs On the FR 2 brake the toe and heel shoe return springs are the same On the FR 2S and the FR 2SD each shoe heel spring is short hooked to the anchor end of the shoe and a projection on the anchor pin each shoe toe spring is long hooked between the toe end of the shoe and a spring pin centered on the spider Disassembly FR 2 Fig 2 25 Fig 4 and FR 2S8D Fig 6 Brakes The first disassembly operation is always removal of the brake shoe re tracting springs With brake spring pliers slip looped ends off pins or projections on the anchor and ad justing supports When the wheel cylinder connecting tube is removed not position of tube and fittings on the brake to avoid er ror in reassembly Difficulty may be encountered in the bleeding operation if tube is assembled in the wrong lo cation Note A Note B Whenever shoes are rem
20. Vacuum Connection Service Rernove the vacuum connection elbow from the intake manifold every 10 000 miles and in spect the elbow and vacuum line for any possible obstruction Clean the elbow and reinstall Fig 8 Vacuum Line Oil Bath Air Cleaner E 4A 22787 PRINTED IN UNITED STATES OF AMERICA Donated by John amp Susan Hansen For Personal Use Only HYDROVAC POWER L LINE MOTOR SERVICE MANUAL Section B Page 6 BRAKE TROUBLE CHART FOR VEHICLES EQUIPPED WITH HYDROVAC UNITS TRUCK BRAKE TROUBLES ARE EASILY DIAGNOSED IF THE COMPLAINT IS UNDERSTOOD THEY WILL ALWAYS SHOW UP IN ONE OR MORE OF THE FOUR WAYS LISTED BELOW THE DRIVER MAY REPORT OTHER SYMPTOMS BUT THESE WILL NOT HELP IN YOUR ANALYSIS BE SURE TO HAVE THE DRIVER TELL YOU WHICH OF THESE FOUR CONDITIONS HE HAS NOTICED IF AT ALL POSSIBLE DRIVE THE TRUCK AND ACTU ALLY FEEL THE CONDITION THE FOUR WAYS OR CONDITIONS POSSIBLE SOURCE OF TROUBLE 1 Vacuum failure due to a Faulty vacuum check valve b Collapsed vacuum hose c Plugged vacuum fittings 4 Bound up pedal shaft 3 Glazed linings 4 Grease or brake fluid on linings 5 Hydrovac trouble No 1 Hard Pedal 1 or brake fluid on linings 2 Scored drums 3 Anchor pins bound up 4 Hydrovac valve trouble No 2 Grabby Brakes l Brakes need adjustment 2 Air in hydraulic system
21. b Shoes improperly set c Backing plates loose on axle d Front spring U bolts loose e Different makes of lining f Tires not properly inflated Remedy Replace with new lining of same make Grease soaked linings cannot be sal vaged by washing or cleaning b Refer to MAJOR ADJUSTMENTS brake shoe adjustment sections Donated by John amp Susan Hansen For Personal Use Only BRAKES L LINE MOTOR TRUCK SERVICE MANUAL Page 5 c Loose backing plates permit the brake 7 LIGHT PRESSURE ON PEDAL SEVERE assembly to shift on the locating bolts BRAKES This shifting changes the predetermined centers and causes unequal efficiency Cause Tighten backing plate and readjust shoes with feeler gauge Brake shoes not properly adjusted d Loose spring U bolts permit the axle to b Loose backing plate on axles shift on the springs and run out of line This is noticed especially when a high c Grease soaked lining braking torque is developed Tighten U bolts at their proper location on Remedy spring mE Consult remedy b under No 4 e Different makes of linings have different braking efficiency Two different makes b Consult remedy c under 4 one with high efficiency and one with low efficiency would cause truck to pull to c Consult remedy a under No 4 one side f All tires should be properly inflated 5 SPRINGY SPONGY PEDAL a Brakes shoes not prop
22. can now be stretched and 1 Do not assemble parts dry Coat parts and forced off of each piston Take care not inside of cylinder bore with clean brake to mar piston bearing surface or cup groove fluid before assembly 5 In turn clamp each connecting link 35 in 2 Stretch cups 25 and 30 into place on pistons vise Pry off each boot retainer sleeve 24 and 29 Cup lip must face inward to Remove boots 32 ward spring groove side of piston Assembly 3 Slip cup back up ring segments 26 and 31 into place on each piston Segment must be Note D Wheel cylinders are identical One placed behind the cup lip and segment lip side of the cylinder has a long stroke must face in same direction as cup lip in comparison to the other side to take care of increased piston travel made 4 Assemble boots 32 and boot retainer necessary when the brake is adjusted sleeves to connecting links 35 Force to compensate for lining wear The sleeves over boots to hold boots in place cylinder inlet and bleeder ports are links offset toward the short stroke side The long stroke piston has greater 5 Place long stroke and short stroke piston length than the short stroke piston assemblies 23 and 28 in correct positions and is also identified by a circular slot in cylinder with spring 27 between pistons machined at the bottom of the connect Piston connecting link sockets must face out ing link socket Pistons must be ward and cup lips face inward
23. 1 194 Hydraulic Hydraulic 13x2 1 4x5 16 13x2 1 4x5 16 15x2 1 4x5 16 16x4x3 8 15x4x3 8 16x4x3 8 Hydraulic 12 1 8x2 1 4x5 16 13 2 1 4 5 16 15x3x3 8 15x4x3 8 12 1 8x2 1 4x5 16 13x2 1 4x5 16 15x2 1 4x5 16 16x5x3 8 13x2 1 4x5 16 15x2 1 4x5 16 15x4x3 8 15 5 3 8 ws s 16x6x3 8 aam 1 3 4 1 3 4 1 1 4 1 1 8 1 1 4 1 1 4 1 1 2 1 3 4 2 2 2 2 2 REM DUE MUR SEM DERE QUEE 1 3 4x1 7 16 1 1 2 1 7 16 1 1 2x1 7 16 1 1 2x1 7 16 1 3 4 1 7 16 1 3 4 1 7 16 Standard Standard Standard Standard Standard 375278 375279 375279 375279 4 375218 375278 9172 VES Single Guided Single Guided Single Guided Single Guided inci Guided Single Guided These hydrovacs contain a residual pressure check valve and must be used with a master cylinder that does not have a residual pressure check valve m 1120 gt o TVANVW AONUL ANITI 9 INN LSAS Donated by John amp Susan Hansen For Personal Use Only HYDRAULIC BRAKE SPECIFICATIONS Continued LF 190 1 201 TRUCK MODEL LF 191 L 204 L 211 LF 192 Brake Lype w e w lt rd Hydraulic Hydraulic Hydraulic Hydraul
24. 4 Checkcompressordrive for alignment belt tension etc 5 Checktobe sure compressor mounting bolts are secure Operating Tests Because of the many different types of air brake systems found on different types of vehicles it is difficult to set up any specific series of tests to determine the serviceability of a compressor on a vehicle Failure of the compressor to maintain normal air pressure in the air brake system of a vehicle usually denotes loss in efficiency due to wear provided leakage in the remainder of the system is not excessive Another sign of wear is excessive oil passing If eitherof these conditions develop and inspection shows the remainder of the air brake equipment to be in good condition the compressor must be repaired or replaced Air Leakage Tests Excessive leakage past the discharge valves can be detected by fully charging the air brake system and then with the engine stopped carefully listening at the compressor for the sound of escaping air This must be done in a quiet place and if air pressure can be heard escaping inside the compressor the discharge valve leakageis excessive and the compressor cylinder head or the Complete compressor must be replaced 2 With the airbrake system fully charged governor cut out coat the unloading box cover with soapsuds to check for leakage past the unloading diaphragms Leakage of a one inch soap bubble in three seconds is permissible If excessive leaka
25. OF AMERICA Donated by John amp Susan Hansen For Personal Use Only L LINE MOTOR TRUCK SERVICE MANUAL BRAKES AIR Section C Page 13 Testing for Serviceability Operating Tests 1 Apply brakes and observe that push rods move out promptly without binding 2 Release brakes and observe that push rods return to release position promptly with out binding 3 Check travel of push rods to be sure it is at the minimum without brakes dragging Caution Always be sure the correct release spring is used in any brake chamber Also be sure the brake chamber on the opposite side of the axle of the vehicle has the same release spring otherwise uneven braking will result If anew diaphragm is installed in the brake chamber on one side of the vehicle a new one also should be installed in the corresponding brake chamber on the other side otherwise this may also cause uneven braking After the brake chamber is installed the brakes must be adjusted and checks made to be sure the linkage does not bind Adjustment of the push rod length by altering the location of the yoke may be necessary With brakes re leased the angle formed by the push rod and slack adjuster must be greater than 909 and all slack adjusters should be set at the same angle With the brakes fully applied after be ing adjusted this angle should still be greater than 909 In other words the slack adjuster should not go over center when the brakes are applie
26. Page 11 Push locking sleeve in to disengage This illustration shows the locking sleeve in its disen gaged position Be sure this is held in disengaging thead justing screw when making adjustments Use either an open end or socket wrench in making adjustment Make certain locking sleeve is held in thereby disengaging the locking mechanism Never use a wrench on the sleeve portion A 22908 Fig I2 Illustrates Locking Sleeve Adjust ing Nut CENTER LINE OF SLACK ADJUSTER N APPLIED POSITION SHOULD NEVER GO OVER CENTER APPLIED s sP RELEASED e TO THIS ANGLE NEVER LESS THAN 90 PRINTED IN UNITED STATES OF AMERICA Testing Adjust brakes and note brake chamber push rod travel whenbrakes are applied Make several brake applications and again check push rod travel Push rod travel must remain the same as it was after adjustment If the push rod travel increases or if difficulty is experienced in keeping the brakes adjusted in service the slack adjuster must be replaced When slack adjuster movement does not give the desired brake action adjustment of the push rod length by altering the location of the yoke may be necessary With brakes re leased the angle formed by the push rod and slack adjuster must be greater than 909 and all slack adjusters should be set at the same angle With the brakes fully applied after be ing adjusted this angle should
27. Piston assembly long 45 Dust shield 22 Piston long 46 Bolt mounting dust shield 23 Cup piston 47 Lockwasher dust shield mounting bolt 24 Protector segment cup piston Donated by John amp Susan Hansen For Personal Use Only BRAKES L LINE MOTOR TRUCK SERVICE MANUAL r Page 5 HYDRAULIC BRAKES BRAKE SHOE ADJUSTMENTS AND SERVICING REAR BRAKES 16 1 2 x 7 1 8 TYPE FR 2 SD FIGS 5 and 6 L 204 L 210 L 211 Wheel cylinder Retracting spring Wheel cylinder cover long se Bleeder valve Ee Pd ES Brake shoe Retracting spring long 14222 AL f lini AE ve nings A VG 2 Z e lt c m P bd adjusting worm ES ei Vm lt ay Wheel cylinder Retracting spring Retracting spring short Wheel cylinder cover short A 23195 Internal View External View Dust Shield Removed Fig 5 Rear Brake Type FR 2SD PRINTED IN UNITED STATES OF AMERICA Donated by John amp Susan Hansen For Personal Use Only BRAKES v YI ll d ee L LINE MOTOR TRUCK SERVICE MANUAL Page 6 A A 22910 Fig 6 Rear Brake Exploded View Type FR 2SD Item DESCRIPTION DESCRIPTION No Piston assembly long 1 Spider and pin assembly 2 Pin retracting spring Piston long 3 Pin anchor Cup piston 4 Screw adjusting Protector segment cup p
28. Tork Brake is a floating shoe type which has two identical shoes 2 Fig 2 arranges on the backing plate 1 so that their toes are diagonally oppo site Two double end wheel cylinders 21 are arranged so that one cylinder is mounted between each shoe toe and shoe heel equal amount of hydraulic force is thus applied at each end of each shoe The wheel cylinders are not bolted directly to the backing plate instead they are held in position by shoe anchor block 20 The anchor blocks are bolted to the back ing plate Each anchor block serves as a shoe stop and shoe centering point and provides the tulcrum around which the shoe pivots when the orake is applied Both shoes are always pri mary shoes forward acting independently actuated in either direction of rotation Shoes anchor at either toe or heel depending upon the rotation of the brake drum pivot pad is placed it both shoes toe and shoe heel The pad at the hoe toe is an integral part of the shoe adjusting screw 7 component of the adjusting mech inism which is placed in the shoe toe on this rake The adjusting screw is held in the shoe by means of worm wheel 12 which threads mto the screw The worm wheel in turn meshes vith a worm 10 which is rotated to effect brake djustment The worm has a hex bore so that t can easily be turned with a 3 8 hex brake vrench Adjustment slots A and B Fig 1 n the brake backing plate provide access to ac
29. When installing new shoes lay the shoes out in pairs according to their position on the iruck The rear secondary shoe is the shoe with longer lining Rear brakes only On rear brake shoes attach parking brake levers to backing plate side of shoe web using lever pin spring and retainer Squeeze ends of retainer lock together after assembly of retainer Thread the star wheel adjusting screw into the pivot nut to the limit of the thread and assemble star wheel adjusting screw and adjusting screw spring to the adjustment end of the shoes with pivot nut against the right hand shoe NOTE Always assemble pivot nut on the right hand shoe regardless of position of shoes on the truck Guide forked end of shoe links over anchor end of shoe web and attach shoes to backing plates by means of shoe hold down pins springs and cups On rear brakes only assemble spring on strut against strut shoulder and assemble strut between front primary shoe and parking brake lever The small loop of Spring rests against inside of shoe web on right hand brake and on outside of shoe web on left hand brake On rear brakes only attach cable to parking brake lever by compressing cable retracting spring and sliding cable into loop at end of lever Attach retracting springs to shoes and anchor pins If springs show signs of hav ing been overstressed they should be re placed PRIMTED N UNITED STATES OF AMERICA Donated by John amp Susan Han
30. a seal to prevent fluid or air being drawn into the system through the bleeder screw during the bleeding operation Fluid passed through the valve on the pressure stroke can return into the master cylinder barrel only by raising the entire valve from its seat The valve is held in place by the cup return spring When the pressure on the returning fluid drops below 6 to 8 pounds the spring closes the valve and the system is under a slight pressure This pressure will not cause the shoes to drag It is used to assure a positive seal at the wheel cylin der cup packings The valve does not control brake pedal move ment Do not try to remedy this complaint by changing the valve NOTE On vehicles equipped with certain models of Hydrovacs the check valve is located in the Hydrovac slave cylinder tube and where this is the case no check valve is used in the master cylinder See Hydrovac Specifications Wheel Cylinders Fig 2 and 3 Two types of wheel cylinders are used in the hydraulic brake system Different combinations of these two types of cylinders are used on different model trucks Fig 2 illustrates a single piston wheel cylinder and Fig 3 illustrates a double piston wheel cylinder The wheel cylinder assembly is the unit that changes the applied hydraulic pressure into mechanical force to actuate the brake shoes A 22743 Fig 2 Typical Wheel Cylinder Single piston type Boot Piston Cup eo eu ette
31. compression of air is controlled by the governor which acting in conjunction with the compressor unloading mechanism stops or starts compression when these maximum and minimum reservoir pressures are reached Donated by John amp Susan Hansen For Personal Use Only EA L LINE MOTOR IRUCK SERVICE MANUAL BRAKES AIR Section C Page 9 TUBE LOCK NUT ADJUSTING SCREW ADJUSTING SCREW BRACKET UPPER VALVE GUIDE EXHAUST PORT SHIMS lt UPPER VALVE UNLOADING MECHANISM LOWER VALVE STRAINER LOWER VALVE SPRING Fig 9 Sectional View Of Governor FROM RESERVOIR A 9366 The design of the compressor governor is based on the principle of a Bourdon tube which is a flattened metal tube bent to a curve that tends to straighten under internal pressure Fig 9 This reaction by the tube due to changes in the air pressure in the tube in creases decreases the spring load on the valve mechanism of the governor and makes the valve mechanism assume its cut in or cut out positions in accordance with the air pressure in the reservoir Two types of gover nor cases will be found in service one being a die cast case and the other a pressed steel case Both types of cases are interchangeable with each other and the working parts of the governor used in both types of cases are iden tical Preventive Maintenance Every Six Months or After Each 10 000 Miles Remov
32. cover plate A 22940 Front External View Fig Bleeder valve Adjusting hole cover arking brake cable conduit X33 Fig 3 Rear External View PRINTED IN UNITED STATES OF AMERICA FRONT REAR Wheel cm i BREL y Connecting link Retracting spring lold down pring and cup Hold down spring and Brake shoe ro N N Adjusting screw E A lining mug pa screw spring A 22938 Fig 2 Front Internal View Anchor pin Backing plate Parking brake cross strut A BS Brake shoe j web Wheel cylinder Connecting link Retracting spring Brake shoe e hold down Parking brake Brake shoe lining Parking brake cable retracting spring A Adjusting screw spring Star ead adjusting screw A 23068 Fig 4 Rear Internal View Donated by John amp Susan Hansen For Personal Use Only BRAKES ADJUSTMENTS Section G Page 2 L LINE MOTOR TRUCK SERVICE MANUAL Brake A 22939 Fig 5 BRAKE ADJUSTMENT INSTRUCTIONS Before attempting to make any brake adjust ments whether minor or major be sure that wheel bearings are properly adjusted and that brake backing plates are tight Adjustment For Wear Minor NOTE PERFORM OPERATIONS IN SE QUENCE GIVEN AT BOTH FRONT AND REAR BRAKES UNLESS OTHER WISE NOTED Place parking brake lever in fully released position J
33. faces shoe toe and backing plate adjustment slot slip mounting lugs into place in the anchor block 20 Refer to Note D Slip connecting link ends into sockets pro vided in the shoes Tighten anchor block locknuts 19 with a TORQUE WRENCH Self locking nuts to be effective must not be over tightened Assemble cylinder connecting tube 39 Refer to Note B under Disassembly Replace brake shoe retracting springs 13 Refer to Note G REPLACEMENT OF SHOE ASSEMBLIES For best results new shoe and lining as semblies 2 should have liners of correct thickness ground not buffed to correct radius concentric with the brake drum If this is not done readjustment may be re quired after liners are worn in Replace one shoe on backing plate 1 making sure adjustment worm 10 is aligned with adjustment slot A or B Refer to Note F PRINTED IN UNITED STATES OF AMERICA L LINE MOTOR TRUCK SERVICE MANUAL BRAKES ADJUSTMENTS Section L Page 5 3 Slip guide sleeve 15 on guide bolt 14 Assemble guide washer 16 lockwasher 17 and lock nut 18 Tighten nut securely 4 Repeat Steps 2 and 3 for second shoe 5 Replace shoe retracting springs 13 Refer to Note G Adjustment Lining to drum clearance adjustment is required when shoes are relined and on occasion to compensate for normal lining wear Clearance should be sufficient to avoid brake drag and yet c
34. link am Parking brake X cross strut E uj aw lever 7 Brake shoe Brake shoe web hold down spring ane Backing plate cup Brake shoe 7 Parking hrake cable Adjusting lining retracting spring hole cover es A wo Parking hrake cable Adjusting screw spring A 22783 Fig 3 Rear External View Fig 4 Rear Internal View PRINTED IN UNITED STATES OF AMERICA Donated by John amp Susan Hansen For Personal Use Only BRAKES ADJUSTMENTS Section D Page 2 L LINE MOTOR TRUCK SERVICE MANUAL INTERNATIONAL NV Brake A 22939 Fig 5 BRAKE ADJUSTMENT INSTRUCTIONS Before attempting to make any brake adjust ments whether minor or major be sure that wheel bearings are properly adjusted and that brake backing plates are tight Adjustment For Wear Minor Figs 1 2 3 4 and 5 NOTE Perform Operations in Sequence Given At Both Front and Rear Brakes Unless Other wise Noted 1 Place parking brake lever in fully re leased position Jack up truck until the wheels are free from floor 3 Remove adjusting hole covers 4 Insert screwdriver or special adjusting tool in slot of backing plate to engage star wheel adjusting screw Fig 5 5 Move outer end of screwdriver or special tool toward axle expanding brake shoes to the point where the wheel can just be turned by hand 6 Rear brakes only NOTE Park
35. not disengaging the clutch until the engine reaches idling speed In the event a trailer breaks away froma truck or tractor the driver must immediately apply the brakes and bring the truck or tractor to a stop Then the truck or tractor should be held withthe hand brake while the cut out cocks in the emergency and service lines are closed The truckortractor air brake system will then be recharged to normal pressure When disconnecting trailers from trucks tractors the emergency feature of the air brake system on the trailer is often used to lock the trailer brakes This is approved practice but the air brake system mustnotbe depended upon to hold a vehicle parked The parking brake must always be applied or the wheels blocked PRINTED IN UNITED STATES OF AMERICA Donated by John amp Susan Hansen For Personal Use Only L LINE MOTOR TRUCK SERVICE MANUAL BRAKES AIR Section C Page 3 COMPRESSOR TYPE U connection from governor ux RAE a 24 d valve Air outlet for re reservoir Drain plug 7 Air intake and mh Fig Air ncm Installed IDENTIFICATION Bendix Westing house compressorsareidentified by the number stamped on the name plate riveted to the side of the crankcase Name plates also show the serialnumber and type of the compressor but compressors cannot be identified by the serial number or the type designation The type designation shown on the n
36. rn M AA eee ee eee ee s TF adjusting wrench NI Brake shoe outer N Brake shoe inner Adjust worm Adjusting outer brake shoe A 23454 Fig 9 Brake Adjustment Type FR 2SD Brake To adjust outer brake shoe insert wrench in adjustment slot until flat washer on wrench contacts dust shield see Fig 9 To adjust inner brake shoe insert wrench in adjustment slot until recessed area on wrench just enters dust shield this will assure proper engagement of brake tool in inner ad justment worm MAINTENANCE AND ADJUSTMENT WAGNER SELF CENTERING TYPE FR 2 TYPE FR 28 AND TYPE FR 2SD BRAKES The development of the Wagner type FR 2 Figs l amp 2 type 25 Figs 3 amp 4 and type FR 2SD Figs 5 amp 6 brakes has created new vistas of greater braking efficiency in the medium and heavy duty truck field The type FR Z brake makes available to medium weight trucks the advantages of full self energization shoe wrapping action caused by the drag of the drum on the liners The type FR 2S and the type 250 bring the advantage of full self energization to the heavy duty field and in addition make it possible for vehicles of 30 000 to 45 000 lbs gross weight to utilize the high efficiency of hydraulic braking power to the fullest extent Heretofore heavy vehicles have been limited to a very few special appli cations of hydraulic brakin
37. s e s sz s s s s s s s s s s s s e M OR s wow 3 4 Replacement of brake shoes 5 5 TL 4 Replacement of wheel cylinders Pr 4 SETViCe SpecificallOnS v 4 et v vw CS ge ow OE d wow G Q i oe 5 Wheel cylinder assembly lt v e eee s n ee 4 Wheel cylinder disassembly Gw Qo 9 W NUK 4 SECTION L 160 L 161 L 162 L 163 L 165 LC 160 LC 161 LC 162 REAR BRAKES 14 1 8 x 3 TYPE FR 2 L 164 L 170 L 171 L 172 L 173 L 175 LF 170 LF 171 LF 172 REAR BRAKES 15 x 3 TYPE FR 2 L 174 L 180 L 181 L 182 L 183 L 185 LC 180 LC 181 LC 182 LF 190 LF 191 LF 192 REAR BRAKES 15 x 4 TYPE FR 2 L210 L 211 LF 210 LF 211 LF 212 LF 220 LF 221 LF 222 FRONT BRAKES 16 1 2 x 3 1 2 TYPE FR 2S L 204 L 210 L 211 REAR BRAKES 16 1 2 x 7 1 8 TYPE FR 2SD Bleeding the hydraulic brake PRISES rrr V 9 w ere g 11 Brake adjustment NUR x ROBO deco oS Y SOE Oe HOw W 10 11 Brake component parts 4 ee 2 4 6 Removal of brake shoes J s s s s s e s s o e e e e PTT 5 9 Removal of shoe adjusting mechanism 5 ce e s ss s s a s s as e s s ea sos e e n n 8 9 Removal of wheel cylinders Tr T 9 Replacement of shoe adjus
38. system fully charged the governor cut out and brakes applied coat all tubing lines and fittings with soapsuds to check for leakage No leakage is permissible Leakage at a tubing fitting is sometimes cor rected by tightening the tubing fitting nut this fails to correct the leakage replace the tubing fitting the tubing or both Donated by John amp Susan Hansen For Personal Use Only Donated John amp Susan Hansen For Personal Use Only BRAKES L LINE MOTOR TRUCK SERVICE MANUAL D7 USEMENTS Page 1 HYDRAULIC BRAKES BRAKE SHOE ADJUSTMENTS AND SERVICING L 110 L 111 L FRONT 12x1 3 4 REAR L 120 L 121 on FRONT 12x2 REAR Anchor pin _ 499 Bleeder valve Wheel cylinder cl m j ee x Connecting link Retracting spring 4622 5 e X TY P SS Retracting spring a plate di ME lj Brake shoe Hold down spring and ME Hold down spring and Brake 4 shoe 7 Brake shoe Backing Adjusting S I I Brake shoe i i plate hole cover ining 24 ESSO Adjusting Adjusting screw Fig Front External View screw spring A 22938 Fig 2 Front Internal View Wheel cylinder f Parking brake lever Ancbor pin Bleeder valve pin retainer p Retracting spring ee N N w Backing plate Connecting
39. the locknut Expand brake shoes by tightening star wheel adjusting screw to the point where wheel can just be turned by hand and then back off star wheel adjusting screw 12 to 14 notches Replace adjusting hole covers PERFORM THE FOLLOWING OPER ATIONS AT EACH REAR WHEEL SEE FIGS 3 AND 4 Thread star wheel adjustment screws into anchor brackets to the limit of the thread and assemble locksprings over anchor brackets with long end of lockspring in contact with star wheel Assemble shoe links to wheel cylinders Hold anchor button in place against cut out of rear shoe web and guide anchor button into the notch of the anchor bracket Guide forked end of shoe links over shoe web Donated by John amp Susan Hansen For Personal Use Only BRAKES MENES L LINE MOTOR TRUCK SERVICE MANUAL Section I Page 4 24 Apply a thin coating of suitable lubricant comparable to Lubriplate to one side of shoe hold down washer and assemble this side of hold down washer against shoe web Place a 006 feeler gauge between center shoe ledge and rim of shoe with shoe in place against the anchor bracket and ad justing screw pad assemble hold down nut and draw down tight against washer back off one castellation and insert cotter key 25 Attach retracting springs black spring to brake shoe and anchor bracket and yellow spring to brake shoe and anchor bracket stud 26 Assemble front shoe to backing plate in the
40. unit which is connected to the truck or bus braking system by a hydraulic line from the vehicle brake master cylinder to the hydro vac and a hydraulic line from the hydrovac to the wheel cylinders of the vehicle brake system Vacuum for operation of the hydrovac is obtained from the engine intake manifold The hydrovac is a self contained unit having no external rods or levers exposed to dirt or moisture to rust and corrode Figs and 2 illustrate the single piston 6 3 4 diameter hydrovac Figs 3 and 4 illustrate the single guided piston 9 1 2 diameter hydrovac Figs 5 and 6 illustrate the tandem piston 9 1 2 diameter hydrovac Bleeding Instructions Bleed the hydrovac and wheel cylinders with the engine stopped bleeding the hydrovac first at the two bleeder valves Figs 2 4 and 6 in the control valve and in the slave cylinder in the following manner l Attach bleeder tube to bleeder valve No 1 by pushing the end of tube over the bleeder valve 2 Insert the end of bleeder tube in a con tainer containing a small amount of brake fluid 3 Unscrew the bleeder valve 3 4 turn and depress brake pedal by hand Allow the pedal to return quickly to the OFF position NOTE Bleeding instructions for all vehicles having the residual check valve located in the master cylinder recommend allowing the brake pedal to return to the OFF position slowly However in brake systems where the residual check valv
41. 21 Attach retracting springs to shoes and anchor pin If springs show signs of having been overstressed they should be replaced Install brake drums For lubrication and adjustment of front wheel bearings see wheel section NOTE It may be necessary to change the position of the shoe eccentric when assembling drum over shoes DO NOT LOOSEN ANCHOR PINS UNLESS INSPECTION OF LINING TO DRUM CLEARANCES INDICATE NEED FOR REPOSITIONING OF ANCHORS Loosen eccentric adjustment locknut and turn eccentric adjustment in the direction of forward wheel rotation until the upper secondary shoe begins to drag Then turn eccentric in opposite direction until brake is just free of drag Hold eccentric and tighten eccentric locknut Check lining to drum clearance at both ends of the upper secondary shoe The clearance at both ends of the upper second ary shoe should be 010 If the clearance at the anchor end of the shoe is greater than the clearance at the adjustment end by 003 or more it will then be necessary to adjust the anchor pin To adjust the anchor pin loosen locknut 1 4 to 1 2 turn and tap anchor pin toward the front or rear of truck to provide the correct clearance When the desired lining to drum clearance is obtained tighten anchor pin nut with a 16 wrench and then recheck upper secondary shoe clearances NOTE If anchor pin nut is loosened too much the anchor pin may shift when tightening
42. 3 Hydraulic leak 4 Master cylinder fluid reservoir needs replen ishing 5 Cracked drum 6 Hydrovac leakage 3 Pedal Goes to Floor or almost to floor l Master cylinder compensating post covered plugged 2 pins bound up 3 Bound up brake pedal shaft 4 Brakes improperly adjusted 5 Faulty hydraulic check valve at master cylinder or hydrovac 6 Hydrovac valve or ball check trouble 4 Brakes Fail to Release Donated by John amp Susan Hansen For Personal Use Only L LINE MOTOR TRUCK SERVICE MANUAL BRAKES HYDROVAC POWER Section B Page 7 Hydrovac Check The following data will assist in the check ing of brake systems utilizing the Hydrovac Power Unit The unit should be checked on the vehicle to determine that the trouble is not elsewhere in the brake system The various units of the brake system should be checked individually for damage or misadjustmentbe fore proceeding with the hydrovac check good quick way to check the hydrovac to determine whether it is operating at all is as follows 1 With the vehicle parking brake applied clutch released and transmission in neu tral position press the brake pedal to about a medium brake application and hold 2 Turn the ignition switch to ON and start the engine 3 Shortly after the engine starts the brake pedal pressure will be felt to relieve it self This is
43. 9 Pres sure settings may be lowered by turning the adjusting screw counterclockwise The lock nut must be tightened after any adjustment 5 If the governor cannot be adjusted to cut in and cut out at the proper pressure set tings it should be replaced 6 Adjustment of the range between the cut in and cut out pressure is made by remov ing shims beneath the upper valve guide Fig 9 to increase the range or by installing addi tional shims to decrease the range Leakage Tests 1 Remove cover and with the governor in its cut out position test for leakage by ap plying soapsuds to the exhaust port 2 With the governor inits cut in position test for leakage by applying soap suds to the exhaust port 3 Leakage in excess of a one inch soap bubble in three seconds is not permissible in either of the above tests H excess leakage is found the governor must be replaced 4 Install cover after making tests SAFETY VALVE Description 1 The purpose of the safety valve is to protect the air brake system against excessive air pressure Should the air pressure in the air brake system rise above the setting of the safety valve at 150 pounds the valve opens and permits pressure above 150 pounds to be ex hausted It is located on one of the reservoirs 2 The safety valve consists of a spring loaded ball check valve which is set to blow off at 150 pounds air pressure Fig 10 Donated by John amp Susan Hansen F
44. AKES ADJUSTMENTS Section E Page 1 12 x 1 3 4 FRONT REAR Wheel cylinder pa _ Retracting spring 2 SN Connecting link Retracting spring plate Brake shoe web Hold down E f ies 1 AL lt shoe T ad ac OA Wheel rotation NI uM Hold down jM spring and Brake WS 1 lt cup shoe ens shoe Ko SS S Wix Pas 7 2 lining Brake shoe aZ lining P Adjusting Adjusting screw screw spring A 22938 Fig 2 Front Internal View Wheel cylinder Anchor pin Connecting link Brake shoe web Retracting spring Retracting spring Brake hold down spring and cup WN een 7 lini 4 74 x UY j e ming aa Adjusting screw spring A 22927 oo Star wheel adjusting screw Fig Rear Internal View Donated by John amp Susan Hansen For Personal Use Only BRAKES ADJUSTMENTS Section E Page 2 Backing plate Adjusting tool A 22939 BRAKE ADJUSTMENT INSTRUCTIONS Before attempting to make any brake adjustments whether minor or major be sure that wheel bear ings are properly adjusted and that brake backing plates are tight Adjustment For Wear Minor NOTE PERFORM OPERATIONS IN SE QUENCE GIVEN AT BOTH FRONT AND REAR BRAKES UNLESS OTHER WISE NOTED 1 Place parking brake lever in fully released position Jack up truck until the whee
45. BLEEDING THE HYDRAULIC BRAKE SYSTEM Vehicle brake systems using the Type FR 2 FR 25 FR 25D foundation brake are bled in similar manner to other hydraulic systems METHOD A Bleed wheel cylinders in the following order Type FR 2 and 28 only 1 Cylinder nearest to road 2 Cylinder highest from the road Type FR 2SD Dual Brake only 1 Bleeding both cylinders of the FR 2SD brake is accomplished through one bleeder valve located on the high cylinder METHOD B If brake is mounted so that both cylinders are almost in a vertical plane it may be necessary to surge bleed the system 1 Bleed brakes at all wheels inregular manner using Method A above 2 At each wheel cylinder in turn open bleeder valve and then kick pedal down sharply several times Close bleeder valve This action creates turbulence in each cylinder forcing out any remaining trapped air Donated by John amp Susan Hansen For Personal Use Only BRAKES Sc om L LINE MOTOR TRUCK SERVICE MANUAL Page 12 SERVICE SPECIFICATIONS LINING LENGTH Measured Inside Arc Both Linings FR 2 Brake 14 1 8 Drum Diameter 14 1 8 15 Drum Diameter 15 FR 2S Brake 16 1 2 Drum Diameter 7 3 4 Block Two used per shoe FR 25D Brake 16 1 2 Drum Diameter 7 3 4 Block Two used per shoe LINING WIDTH FR 2 Brake 14 1 8 Drum Diameter 3 15 Drum Diameter ju ue
46. CA Fig 3 Donated by John amp Susan Hansen For Personal Use Only BRAKES ADJUSTMENTS Section H Page 2 L LINE MOTOR TRUCK SERVICE MANUAL Brake shoe Backing plate A 22939 Fig 5 BRAKE ADJUSTMENT INSTRUCTIONS Before attempting to make any brake adjust ments whether minor or major be sure that wheel bearings are properly adjusted and that brake backing plates are tight Adjustment For Wear Minor PERFORM OPERATIONS IN SE QUENCE GIVEN AT BOTH FRONT AND REAR BRAKES UNLESS OTHER WISE NOTED NOTE 1 Place parking brake lever in fully released position 2 Jack up truck until the wheels are free from floor 3 Remove adjusting hole covers 4 On front brakes only loosen eccentric lock nut and turn eccentric adjustment in the direction of forward wheel rotation until upper secondary brake shoe drags Then turn eccentric in opposite direction until upper secondary brake shoe is free of drag Hold eccentric and tighten eccentric locknut 5 Insert screwdriver or special adjusting tool in slot of backing plate to engage star wheel adjusting screw Fig 5 6 Move outer end of screwdriver or special tool toward axle expanding brake shoes to the point where the wheel can just be turned by hand 7 Back off star wheel adjusting screw 12 to 14 notches and then check to see that brake drum turns freely On rear brakes it may be necessary to tap the backing plate lightly to p
47. Donated by John amp Susan Hansen For Personal Use Only BRAKES L LINE MOTOR TRUCK SERVICE MANUAL Section C Page 6 VV pedal stop or linkage if necessary to prevent this interference After any adjustment check brake valve delivery pressure c Be sure the brake valve lever strikes the cover of the valve when the brake pedal is in released position If necessary adjust pedal rod length Lever pin lt Roller Colter pi lt C gt pin pin KS EN c Roller pin r n Stop y 74 Boot M S Stud screw NS N pe Lock INN r ost RENN gg CC C CC Seal RN A 7 LO AQ US Shims 2 S fL Lockwasher 2 Upper body Diaphragm 7 Seal Return spring N Seal JUPE Capscrew Shims NE Body a Seal A Inlet body ae Lock washer ES Nut Stud A 22837 Fig Sectional View Of Brake Valve Testing For Serviceability Operating Tests 1 Check the delivery pressure of the brake valve usinganaccurate airpressure test gage On vehicles having trailer connections the test gage may be conveniently connected to the service line outlet at the rear of the ve hicle Note that the first movement of the brake pedal towards applied position after the slack is taken up causes the brake valve to deliver approximately five pounds air pressure Note that approximately full reservoir pressure is delivered by the
48. Donated by John amp Susan Hansen For Personal Use Only BRAKE SYSTEM L LINE MOTOR TRUCK SERVICE MANUAL Index Page 1 BRAKE GROUP INDEX SPECIFICATIONS Page Air brakes 359 927 8 oe ee ae eS x 6 7 Hydraulic Drakes s erg 44 9 do S ELE os ee eS SK 1 9 SECTION A HYDRAULIC BRAKE SYSTEM Bleeding lines EEEE RETES 8 V Q b Q Q eee 3 Brake pedal adjustment 9 4k EA CES OS P S 2 G re daa xd S Ww A Ow amp 2 Check valve Q S TERET P OS o ex s 2 Hydraulic brake sys tem QW w T 1 Hydraulic fluid o be 6a he QO W Q d TIT 1 Maintenance hints EET xw 4 x uc 3 4 5 Master cylinder Tm 1 Repairs to master cylinder and wheel cylinders is a d x w A S 2 Wheel ey hndePS c x ES Oe 309 w W S ox TIT m 2 SECTION HYDROVAC POWER BRAKE UNITS Bleeding instructions TP 4 DescriDiOH 24 X w x Q WX Xo 4 Hydrovac air inlet filter 5 5 3 1509 RUS QQ 3 3 wc
49. Engage notched push rod ends into slots provided at each end of the shoes Replace brake shoe retracting springs Refer to Note G Donated by John amp Susan Hansen For Personal Use Only L LINE MOTOR TRUCK SERVICE MANUAL INTERNATIONAL VII TO REPLACE SHOE ASSEMBLIES 1 For best results new shoe and lining as semblies should have liners of correct thickness ground not buffed to the correct radius concentric to the brake drum 2 Slide anchor pins into supports so that anchor can be engaged by the shoe heel 3 Replace shoe on backing plate or spider making sure that toe is aligned with the adjusting screw and heel with the slot pro vided in the anchor pin Slip shoe guide pin through spider or backing plate guide hole located in shoe web Install washer and shoe guide spring C clip Repeat step for other shoe or shoes 4 Replace shoe retracting springs Refer to Note G On FR 28 and FR 2SD type brakes replace the dust shield enclosure after completing assembly of the brake Adjustment Lining to drum clearance adjustment is required when the shoes are relined and on occasion to compensate for normal lining wear Clearance should be sufficient to avoid brake drag and yet close enough to afford a good pedal reserve Manually operated and vacuum hydraulic actuated brakes require adjustment or relining when the pedal reserve approximates 2 that is when the pedal drops to within 2 of th
50. FORM OPERATIONS IN SE QUENCE GIVEN AT BOTH FRONT AND REAR BRAKES UNLESS OTHER WISE NOTED Place parking brake lever in fully released position Jack up truck until wheels are free from floor Remove wheels hubs and drums Remove adjusting hole covers Remove brake shoes and inspect linings for excessive wear grease loose rivets or other damage Install new lining if old lining shows excessive wear or is saturated with grease or brake fluid Inspect brake drums for scores run out or cracks scores are not too deep run out does not exceed 010 drums may be machined If drums are badly scored or cracked they should be replaced Inspect wheel cylinders for signs of fluid leakage or deteriorated rubber dust boots If brake fluid is leaking out of wheel cylin ders replace or recondition wheel cylinders Clean grease and dirt off of backing plate and sand down shoe ledges if rusted or ridged Disconnect parking brake cables to rear brakes at intermediate lever end Wipe off dirt and grease from exposed portion of cables and pull cables through conduits as far as possible from the brake end and wipe off old grease Donated by John amp Susan Hansen For Personal Use Only L LINE MOTOR TRUCK SERVICE MANUAL BRAKES ADJUSTMENTS Section G Page 3 11 12 13 14 15 16 17 18 19 20 Apply generous coating of cable lubricant to cables and slide cable
51. HEEL SEE FIGS 1 AND 2 NOTE 4 Loosen eccentric locknut and turn eccentric adjustment in the direction of forward wheel rotation until upper secondary brake shoe drags Then turn eccentric in opposite direction until upper secondary brake shoe is free of drag Hold eccentric and tighten eccentric locknut L LINE MOTOR TRUCK SERVICE MANUAL 5 Insert screwdriver or special adjusting tool in slot of backing plate to engage star wheel adjusting screw Fig 5 6 Move outer end of screwdriver or special toward axle expanding brake shoes to the point where the wheel can just be turned by hand 7 Back off star wheel adjusting screw 12 to 14 notches and then check to see that brake drum turns freely 8 Replace adjusting hole covers PERFORM THE FOLLOWING AT EACH REAR WHEEL SEE FIGS 3 AND 4 NOTE 9 Insert screwdriver or special adjusting tool into upper or front shoe adjusting screw slot of backing plate to engage star wheel adjusting screw Fig 5 10 Move outer end of screwdriver or special adjusting tool toward axle expanding front brake shoe to the point where the wheel can just be turned by hand 11 Back off star wheel adjusting screw until brake drum is just free of brake drag approximately 6 notches 12 Insert screwdriver or special adjusting tool into lower or rear shoe adjusting screw slot of backing plate and expand rear brake shoe to the point where the wheel can just be turned
52. NAL V PARKING BRAKE FOR L 205 L 210 L 211 L 212 LF 210 LF 211 LF 212 LF 220 LF 221 LF 222 TRUCKS Parking Brake Adjustments See Fig 4 Note Perform Operations in sequence given l Place parking brake lever in extreme for ward release position NOTE Brake cam lever must rest squarely on the upper brake band bracket To correct this position remove clevis pin and readjust yoke The lining to drum clearance of 020 to 030 is obtained as follows a Tighten nuts 3 on bolt 4 to give 2020 to 030 clearance between lower half of shoe and drum b Tighten nuts 1 on adjusting bolt 2 to give 020 to 030 clearance be tween upper half of brake shoe and drum c Tighten nuts 5 on bracket bolt 6 just enough to hold adjustment obtained in paragraph b d Lock all adjustments w ul Sy H H HH oee _ A 23194
53. Only BRAKES HYDRAULIC Section Page 4 b In cases where the anchor pins have been disturbed and the relation of the arc of the shoes to drums changed lining will wear rapidly and the braking ef ficiency of that particular wheel will be reduced To overcome this condition follow instructions as outlined in MAJOR ADJUSTMENTS brake shoe adjustment sections c A leak in the system will allow the pedal under pressure to go to toe board gradually If no leaks are found at wheels or joints remove master cylinder and check bore of barrel for scores or scratches d Air in the system will cause a springy rubbery action of the pedal Should a sufficient quantity be introduced into the system the pedal will go to toe board under normal pressure System should be bled e Brake pedals should be set to give the correct amount of free movement before the pressure stroke starts Excessive free movement reduces the active travel of the master cylinder piston which in turn determines the amount of working fluid to be expelled from the master cylinder into the lines or system f The fluid level in the supply reservoir should be checked at regular intervals Should the reservoir become empty air will be introduced into the system necessitating bleeding ALL BRAKES DRAG Cause a Mineral oil in system b Pedal improperly set Remedy a The introduction of mineral oil such as engine oil kerosene or any
54. Refer to Note assembled in proper position within the D cylinder If pistons are reversed fluid will have difficulty entering the 6 Place assembled boots and links in boot re cylinder chamber and it may be forced tainer caps 33 and fit on cylinder Crimp out of the short stroke side of the each cap in at least three places into cylinder The long stroke side of grooves machined on ends of cylinder Donated John amp Susan Hansen For Personal Use Only VI REPLACEMENT OF SHOE ADJUST MENT MECHANISM 1 Do not lubricate parts Refer to Note E Assemble end thrust washers 8 sleeve 9 worm 10 and worm wheel 12 in place Sleeve slot must face the worm wheel to allow worm and wheel to mesh 3 Push worm retainer snap ring 11 in place making sure it snaps into the groove pro vided in the shoe 4 Start adjusting screw 7 into worm wheel 12 thread Adjust to full off position Curvature of pad on adjusting screw must be in proper plane to permit it to rock on anchor block when shoe is replaced on back ing plate VII REPLACEMENT OF WHEEL CYLINDER WITHOUT DISTURBING SHOES 1 Make sure that backing plate is clean so that cylinder and anchor block 20 will fit properly when mounted Make sure spring washers 34 are in position on the two lugs machined on the cylinder casting 3 Spread shoes as far apart as possible t Holding wheel cylinder so that long stroke side of cylinder
55. SEN ANCHOR PINS UNLESS INSPECTION OF LINING TO DRUM CLEARANCE INDICATES A NEED FOR REPOSITIONING OF ANCHORS Loosen eccentric adjustment locknut and turn eccentric adjustment in the direction of forward wheel rotation until the upper secondary shoe begins to drag Then turn eccentric in opposite direction until brake is just free of drag Hold eccentric and tighten eccentric locknut Check lining to drum clearance at both ends of the upper secondary shoe The clearance at both ends of the upper second ary shoe should be 010 If the clearance at the anchor end of the shoe is greater than the clearance at the adjustment end by 003 or more it will then be necessary to adjust the anchor pin PRINTED IN UNITED STATES CF AMERICA L LINE MOIOR TRUCK SERVICE MANUAL BRAKES ADJUSTMENTS Section H Page 3 19 To adjust anchor pin loosen locknut 1 4 to 20 NOTE ols 22 63 24 25 NOTE 26 1 2 turn and tap anchor pin toward the front or rear of truck to provide the correct clearance When the desired lining to drum clearance is obtained tighten anchor pin nut with a 16 wrench and then recheck secondary shoe clearances NOTE H anchor pin nut is loosened too much the anchor pin may shift when tightening the locknut Expand brake shoes by tightening star wheel adjusting screw to the point where wheel can just be turned by hand and then back off star wheel adjusting screw 12 to 14 notches Rep
56. STMENTS Section K Page 3 Donated by John amp Susan Hansen For Personal Use Only BRAKES L LINE MOTOR TRUCK SERVICE MANUAL Page 4 27 32 19 31 A 22911 Fig 4 Front Brake Type FR 28 Exploded View Item Item No DESCRIPTION DESCRIPTION 25 Spring 1 Spider and pin assembly 2 Pin retracting spring 26 Piston assembly short 3 anchor 27 Piston short 4 Wheel driven adjusting worm 28 piston 5 Wheel driven adjusting worm 29 Protector segment cup piston 6 Worm adjusting shoe 30 Boot assembly Sleeve adjusting worm 31 Push rod 8 Washer end thrust adjusting worm 32 Valve bleeder wheel cylinder 9 Ring snap worm retainer 33 Cover wheel cylinder 10 Shoe and lining assembly 34 mounting wheel cylinder 11 Shoe 35 Lockwasher cylinder mounting bolt 12 Lining 36 Fitting distributor fluid 13 Rivet 37 Bolt mounting distributor fitting 14 Pin shoe guide 38 Lockwasher distributor fitting bolt 15 Washer shoe guide pin 39 Tube assembly connecting short 16 Clip spring shoe guide 40 Tube assembly connecting long 17 Spring retracting shoe toe long 41 Bolt fitting wheel cylinder 18 Spring retracting shoe heel short 42 Gasket fitting inlet 19 Wheel cylinder assembly 43 Fitting inlet fluid 20 Body whee1 cylinder 44 Gasket bolt fitting 21
57. Then turn star wheeladjusting screw in opposite direction until there is but a light drag on the feeler gauge Withdraw feeler gauge NOTE Expanding shoes until feeler gauge cannot be withdrawn insures that shoes are resting against the anchor pin 17 Revolve brake drum So that feeler gauge hole is about 1 1 2 from the anchor end of the rear secondary shoe lining There should be a slightly heavier drag on the feeler gauge at this point If the clearance at the anchor end of the shoe is greater than the clearance at the adjustment end by 003 or more it will be necessary to ad just the anchor pin 18 To adjust anchor pin loosen locknut 1 4 to 1 2 turn and tap anchor pin either up or down to provide the correct anchor pin position After positioning the anchor pin to provide the correct rear secondary shoe clearance tighten the anchor pin lock nut with a 16 wrench and then recheck anchor and adjusting end clearances NOTE If anchor pin nut is loosened too much the anchor pin may shift when tightening the locknut 19 Replace adjusting hole covers PRINTED IN UNITED STATES OF AMERICA Donated by John amp Susan Hansen For Personal Use Only Donated by John amp Susan Hansen For Personal Use Only L LINE MOTOR TRUCK SERVICE MANUAL BRAKES ADJUSTMENTS Section G Page 1 HYDRAULIC BRAKES BRAKE SHOE ADJUSTMENTS AND SERVICING 12 x 1 3 4 2 1 4 LB 140 14 x Adjusting Backing hole
58. V WHEEL CYLINDER ASSEMBLY l Do not assemble parts dry Coat parts and inside of cylinder bore with clean brake fluid 2 Insert spring 16 cup filler 17 and piston cup 18 into cylinder bore Cup filler bumper and cup lip should face closed end of cylinder 3 Place boot 20 on piston 19 making sure boot snaps over shoe guide 4 Install piston and boot Align piston shoe guide slot to accommodate the shoe toe Push boot lip into place in groove machined on end of cylinder V REPLACEMENT OF WHEEL CYLINDERS l Place one cylinder in position on backing plate Install mounting screws 30 and lockwashers 31 small Refer to Notes D and E 2 Install cylinder anchor screw 27 washer 29 and lockwasher 28 large 3 Repeat steps 1 and 2 for second cylinder 4 Install wheel cylinder fittings 24 and tubes 21 Refer to Note B under disassembly VI REPLACEMENT OF SHOE ASSEMBLIES l Install spring anti rattle washer 6 on cam and shoe guide stud 2 pronged side facing adjusting cam 5 2 Place shoe assembly on backing plate with cam and shoe guide stud protruding through shoe slot Locate shoe toe in piston slot and shoe heel in anchor block slot Refer to Note G 3 Replace hold down washer 11 and C washer 12 on cam and shoe guide stud Crimp washer on stud 4 Repeat steps 1 2 and 3 for second shoe 5 Replace shoe retracting springs 13 Refer to Not
59. ack up truck until the wheels are free from floor Remove adjusting hole covers Insert screwdriver or special adjusting tool in slot of backing plate to engage star wheel adjusting screw Fig 5 Move outer end of screwdriver or special tool toward axle expanding brake shoes to the point where the wheel can just be turned by hand REAR BRAKES ONLY NOTE Parking brake cable adjustment should be made at this time Withbrakeshoes still expanded disconnect the parking brake cable at the 9 intermediate lever end Withparking brake lever applied approximately 1 from fully released position pull cables by hand to re move allslack Adjustcables as required at yoke end so that clevis pins can be inserted Insert clevis pins and new cotter pins Back off star wheel adjusting screw 12 to 14 notches and then check to see that brake drum turns freely It may be necessary to tap the backing plate lightly to permit the brake shoes to take a central position REAR BRAKES ONLY Pull parking brake lever back until the rear wheel can just be turned by hand Check rear wheels for even brake drag If drag is uneven loosen the tight brake to provide even drag Replace adjusting hole covers Major Adjustments and Servicing Fig 1 2 3 4 and 5 The following adjustments are performed only when adjustments under Minor Adjustments fail to give satisfactory results or when install ing new shoes or linings NOTE PER
60. ad e 9 0 e 9 5 8 LINING TO DRUM CLEARANCE Freedom from drag plus cam rotation of 9 9 9 o 2 19 109 Donated by John amp Susan Hansen For Personal Use Only Donated by John amp Susan Hansen For Personal Use Only BRAKES ADJUSTMENTS L LINE MOTOR TRUCK SERVICE MANUAL Section K Page 1 HYDRAULIC BRAKES BRAKE SHOE ADJUSTMENTS AND SERVICING L 160 L 161 L 162 L 163 L 165 LC 160 LC 161 LC 162 14 1 8 x 3 REAR BRAKES TYPE FR 2 FIGS 1 and 2 L 164 L 170 L 171 L 172 L 173 L 175 LF 170 LF 171 LF 172 15 3 REAR BRAKES TYPE FR 2 FIGS 1 and 2 LC 180 LC 181 LC 182 15 x 4 L 174 L 180 L 181 L 182 L 183 mi REAR BRAKES LF 190 LF 191 LF 192 TYPE FR 2 FIGS 1 and 2 Star wheel Wheel cylinder cover Adjusting slot cover adjusting screw Retracting spring Backing plate ind Bleeder valve Wheel cylinder A 2321 Internal View External View Fig Rear Brake Type FR 2 PRINTED IN UNITED STATES OF AMERICA Donated by John amp Susan Hansen For Personal Use Only BRAKES SEC MUNDUS L LINE MOTOR TRUCK SERVICE MANUAL Page 2 PF 42 M A 22912 Fig 2 Rear Brake Type FR 2 Exploded Yiew Item Item No DESCRIPTION No DESCRIPTION Spring I Plate brake backing 2 Pin anchor Piston assembly short piston
61. ake valve handle moved to its fully applied position the brake valve must deliver at least sixty pounds pressure Move the brake valve handle to several different positions between fully applied and fully released positions and observe that the air pressure registered by the test gage varies in accordance with the position to which the handle is moved Leakage Tests 1 With brake valve handle in released position coat the exhaust port with soap suds to check for leakage 2 With brake valve handle in fully applied position coat the exhaust port with soap suds to check for leakage 3 Leakage in excess of a one inch soap bubble in one second is not permissible in either of these tests If excessive leakage is found it will usually be caused by dirty or worn valves or valve seats and the inlet and exhaust valve assembly or the complete brake valve must be repaired or replaced Leakage due to dirty valves and valve seats may be corrected by removing the inlet and exhaust valve assembly and cleaning the valves and valve seats Leak age due to wornvalves maybe corrected by in stalling a newinlet and exhaust valve assembly If the valve seats are pitted or worn excessive ly or if the installation of a new inlet and ex haust valve assembly does not correct the leakage the brake valve must be repaired or replaced QUICK RELEASE VALVE Description The purpose of the quick release valve is to reduce the time required to re
62. ame plate is in accordance with the following Type of Cooling 4 6 Flange F Air A Eng Thus a 2 UE 7 1 4 VW compressor is a two cylinder type engine lubricated compressor with a displacement of 7 1 4 cubic feet per minute at 1250 r p m vertically mounted and water cooled PREVENTIVE MAINTENANCE AND TROUBLE SHOOTING Daily Service International trucks are usually equipped with the engine lubricated type air compressor however if the compressor is of the self lubricated type check the oil level in the compressorcrankcaseand replenish if nec essary Donated by John amp Susan Hansen For Personal Use Only BRAKES Section C Page 4 p L LINE MOTOR TRUCK SERVICE MANUAL b Should it be necessary to drain the engine cooling system to prevent freezing al ways drain the compressor cylinder head see Fig DA Every Month or After Each 2 000 Miles a Service compressor air strainer Re move and wash all parts including curled hair in cleaning solvent Saturate curled hair with clean engine oil and squeeze dry before re placing it in the strainer b If compressor is the self lubricated type drain and flush compressor crankcase and refill with clean engine oil c Check compressor mounting and drive for alignment belt tension etc Adjust if nec essary SCREWDRIVER nul A ii ali UNLOADING i GAGE 0 012 IN FEELER LEVER os DISCHARGE LOCK NUT VALVE
63. apply the brakes In flowing to the rear brake chambers the air pressure passes through the quick release valve entering at the top deflecting the dia phragm and its seat to seal the exhaust open ing while the air pressure passes around the diaphragm to the two side connections each leading to a brake chamber In the case of the relay valve 6 wheel models the connections lead to tee connections and from there to each of the four rear brake chambers When the pressure built up in the brake chambers and acting against the brake valve diaphragm is enough to compress the regulat ing spring the diaphragm moves upward allow ing the inlet valve to close by action of its spring The exhaust valve remains closed by action of the inlet valve spring and tilting of the rock er arm Further increase of brake chamber pressure is thus prevented If however there should be leakage from the brake chambers or piping while the brake valve lever remains in this position the resulting drop in pressure under the brake valve diaphragm will cause the regulating spring toagain unseat the inlet valve and restore the lost pressure Release When the foot is removed from the brake pedal the brake valve lever is moved back toward normal position again which relieves the tension on the regulating spring so that the diaphragm will be moved upward to its normal position by brake chamber pressure under neath it This permits the exhaust valve
64. ary until it is against edge of connector body Tighten con necting nut It is only necessary to tighten nut sufficiently to insure an air tight joint 10 When installing a hoseassembly where both ends are permanently connected the hose connector at either end is used as a swivel by loosening the nut on one of the connectors Turn the hose in the loose connector before the connector nut is again tightened This permits the installation of the hose without kinking or twisting HOSE COUPLINGS AND DUMMY COUPLINGS Description 1 Hose couplings provide an easy and convenient method of connecting and disconnect ing air lines between vehicles by hand The design of the hose couplings is such that when two of them are coupled together pressure is put on two rubber gaskets making an air tight seal 2 Dummy couplings are made in two general designs somebeing fitted withbrackets to permit them to be rigidly mounted on the vehicle while others are fitted with a chain attaching them to the vehicle The bracket type is used where the dummy coupling is to serve as a fastening for holding hose lines when not in use whereas the chain type is used for blocking off hose couplings rigidly mounted on the vehicle as used on the tractor truck The purpose of the dummy coupling is to prevent the entrance of dirt or other foreign matter into the air brake lines when the lines are not being used Testing 1 With the hose couplings connec
65. assem bly with cleaning solvent and dip in light lubri cating oil before replacing Care should be exercised to make sure the rubber boot is in good condition and properly installed to protect the piston shaft from the element 4 N T li 2 NL P Iston a backin X3 des PST 00 Z Of plate 7 ix N CO x V Z Ar TG O II Hg te CEA Y E 7 VIDES p NA Piston cu s 75 m S stem Yoke I i N plug Piston D Piston Piston stem Set screw Piston cup Spring A 22925 Fig 17 Typical Brake Chamber Piston Type AIR PRESSURE GAGE Description 1 The purpose of the dash mounted air pressure gage is to register the amount of air pressure in the air brake system While air pressure gages of this type are commercially accurate they must never be confused with or substituted for test air gages which are in tended primarily for accurately checking air pressure in the air brake system 2 Only test gages known to be accurate are tobe used for checking brake valve delivery pressures governor pressure settings and other tests Test gages differ from ordinary dashgages in respect to materialand workman ship much as an expensive watch differs from a cheaper one and due to these differences they are moreaccurate over their entire range and maintain their a
66. assembly Diffi culty will be encountered in bleeding operation if tube is assembled in wrong location Note C Whenever shoes are removed always dismantle adjusting mechanism and clean grease dust and dirt from parts and from chambers within the shoe Step By Step Procedure Disassembly 1 REMOVAL OF SHOE ASSEMBLIES 2 1 Remove brake shoe retracting springs 13 Refer to Note A 2 Remove shoe guide bolt nut 18 lockwasher 17 and washer 16 holding shoe in place Shoe 2 easily lifts off 3 other parts may then easily be removed Refer to Notes B and C 11 REMOVAL OF WHEEL CYLINDER 21 WITHOUT DISTURBING SHOES 1 Remove brake shoe retracting springs 13 Refer to Note A 2 Disassemble cylinder connecting tube 39 and tube fitting 41 Refer to Note B 3 At anchor block 20 of cylinder loosen anchor block lock nuts 19 It is not neces sary to completely remove these nuts Donated by John amp Susan Hansen For Personal Use Only BRAKES L LINE MOTOR TRUCK SERVICE MANUAL 7 Section L Page 4 VN V 4 Spread shoes away from cylinder until con the cylinder Greatest length from necting links 35 are cleared inlet port to end of cylinder must be assembled to the backing plate so 5 Push anchor block 20 away from backing that it faces the 1 Shoe Toe ad plate 1 until clearance is sufficient for justment end of shoe 2 Adjust cylin
67. ate wrench in opposite direction to in crease clearance until drag is relieved Then rotate wrench one additional turn to provide working clearance 5 Repeat Steps 3 and 4 on the other shoe or shoes B or A Step By Step Procedure Adjustment Type FR 2SD Brake Figs 5 and 9 The rear wheel brakes are adjusted by means of a special 3 8 hex wrench IH No SE 1731 which has been designed for the purpose of adjusting either the inner or outer brake shoe but not both shoes at one time 1 Make all adjustments with drum cooled to normal temperatures 2 Make sure wheel bearings are correctly adjusted 3 Insert special wrench IH No SE 1731 Figs 5 and 9 in adjustment slot A or B to engage either the inner or outer brake shoe adjusting worm Rotate wrench in the direction of FORWARD wheel rotation to decrease lining to drum clearance Re duce clearance until lining drags on drum 4 Rotate wrench in opposite direction to in crease clearance until 15 relieved Then rotate one 1 additional turn to pro vide the proper working clearance CAUTION Repeat operation at each shoe two shoes to be adjusted at each adjust ment slot in dust shield 5 Repeat Steps 3 and 4 at opposite adjust ment slot B or A NOTE For most accurate adjustment it is not advisable to attempt to adjust both brake shoes simultaneously always pro as outlined above PRINTED IN UNITED STATES OF AMERICA
68. brake valve when the brake pedal is fully depressed If the brake valve does not deliver approximately full reservoir pressure when the brake pedal is fully de pressed adjust the pedal stop or linkage so as to increase the travel of the brake valve lever This should increase the delivered pressure On some vehicles the pedalstop is so arranged as to prevent the brake valve from delivering full reservoir pressure This arrangement must not be altered on such vehicles unless a higher delivery pressure isdesired in order to increase the effectiveness of the brakes When making this adjustment be sure no strain is placed on the valve lever due to the edge of the lever cap striking the cover when the brake pedalis fully depressed Alsobe surethe brake valve lever returns tofullrelease position when the brake pedalis released 2 Hold brake pedal at several different positions between release position and fully de pressed position and observe that intermediate delivered pressures between five and seventy pounds definitely determined by the position in which the brake pedal is held Leakage Tests 1 With brakes released coat the exhaust port with soapsuds 2 With brakes fully applied coat the ex haust port with soapsuds 3 Leakage in excess of a one inch soap bubble in one second is not permissible ineither of these tests If excessive leakage is found the brake valve must be repaired or replaced 4 With brakes applie
69. by hand 13 Back off star wheel adjusting screw until brake drum is just free of brake drag approximately 6 notches 14 Replace adjusting hole covers Major Adjustments and Servicing Figs 1 2 3 4 and 5 The following adjustments are performed only when adjustments under Minor Adjustments fail to give satisfactory results or when in stalling new shoes or linings PERFORM OPERATIONS IN SE QUENCE GIVEN AT BOTH FRONT AND REAR BRAKES UNLESS OTHER WISE NOTED NOTE 1 Place parking brake lever in fully released position 2 Jack up truck until wheels are free from floor 3 Remove wheels hubs and drums Donated by John amp Susan Hansen For Personal Use Only L LINE MOTOR SERVICE MANUAL BRAKES ADJUSTMENTS Section I Page 3 10 NOTE Li Ld 13 14 Remove adjusting hole covers Remove brake shoes and inspect linings for excessive wear grease loose rivets or other damage Install new lining if old lining shows excessive wear or is saturated with grease or brake fluid Inspect brake drums for scores run out or cracks If scores are not too deep or run out does not exceed 010 drums may be machined If drums are badly scored or cracked they should be re placed Inspect wheel cylinders for signs of fluid leakage or deteriorated rubber dust boots If brake fluid is leaking out of wheel cylinders replace or recondition wheel cylinders Clean g
70. caused by the Hydrovac pick ing up the brake application The relief or movement is quite noticeable when the hydrovac is functioning properly If no movement or relief 15 felt at the brake pedal when making the above check it is good practice to check the brake system further be fore centering attention on the hydrovac unit Check as follows 1 Master Cylinder Piston Rod Clearance Make certain linkage is properly adjusted to permit opening of compensating port with brake pedal in normal full released position Failure to properly uncover the compensating port may cause sufficient pressure to be maintained in the brake System to hold the hydrovac valve in a partially applied position and thus cause dragging brakes 2 Restricted Vacuum Lines Check for vacuum at the hydrovac by dis connecting the vacuum line at the hydrovac vacuum connection fitting and holding a thumb over the line with the engine run ning If no vacuum exists or if air flow is slow check vacuum line to manifold for kinks in tubing and collapsed liners in hoses Also test the check valve to be sure it opens Check fitting at engine manifold for restriction 3 Restricted Air Line and Air Cleaner Disconnect the air cleaner line at the hy drovac and blow into the line H the line is restricted check for collapsed hose or tubing Clean or replace air cleaner PRINTED IN UNITED STATES OF AMERICA 4 Brakes Check brake shoe adjustment fo
71. ccuracy over longer periods Testing 1 Check the dash air gage for accuracy The simplest way to do this is to compare the pressures registered by the gage over its normal pressure range with the pressures registeredby a test gage known to be accurate 2 dash gage which loses its accuracy must replaced The continued use of a dash gage showing an error of more than 5 pounds is not recommended CUT OUT COCKS Description 1 Cut out cocks have a tapered key ground to the body to prevent leakage pas sage is provided through the key so that when the key is turned to its open position air is permitted to flow through the cock but when the key is turned to the closed position air is prevented from flowing through the cock Cut out cocksareusedinthe serviceand emergency lines of the tractor truck to provide a means of closing off these lines when they are not being used 2 The cut out cock is open when the handle is at a 90 degree angle with the body of the cock and closed when the handle is parallel with the body of the cock Stops are provided so that the handle cannot be turned beyond its normal positions 3 Always open and close a cut out cock by hand Never strike the handle with a ham mer or similar instrument as the cock would be damaged and leakage would develop Testing 1 With brakes applied and cut out cock closed hose line disconnected test with soap suds for leakage past the key Als
72. d Fig 13 The position of the push rod yoke on the push rod should be adjusted if necessary until these conditions prevail BRAKE CHAMBER PISTON TYPE MIDLAND The Midlandair cylinder Fig 17 requires very little attention but to insure proper oper ation the cylinder should be kept lubricated At intervals of approximately four months or 15 000 miles the air connection at the rear of the cylinder should be removed and one quarter pint of lubricant similar to Elso s 150 LO graphite type grease with 10 neat s foot oil inserted At regular truck overhaul periods the cylinder should be removed taken apart and thoroughly cleaned The piston cup should be inspected and free from cracks scratches and dirt particles If the piston cup is hard or dry it should be immersed in 5 foot oil before reassembling in cylinder If it becomes nec essary to replace the piston cup shellac both Donated by John amp Susan Hansen For Personal Use Only BRAKES AIR L LINE MOTOR TRUCK SERVICE MANUAL Section C Page 14 sides of piston stem plug gasket also shellac threads of piston stem plug and draw up piston stem plug just snugly on ball end of piston stem The inside of the air cylinder and complete piston assembly should be thoroughly cleaned and the wall of the cylinder as wellas the en tire piston assembly should be covered with a lubricant as outlined in first paragraph Cleanbreather hair in piston stem
73. d Servicing Figs 1 2 3 4 5 The following adjustments are performed only when adjustments under Minor Adjustments failto give satisfactory results or when in stalling new shoes or linings PERFORM OPERATIONS IN SEQUENCE GIVEN AT BOTH FRONT AND REAR BRAKES UN LESS OTHERWISE NOTED NOTE 1 Place parking brake lever in fully released position 2 Jack up truck until wheels are free from floor 3 Remove wheels hubs and drums 4 Remove adjusting hole covers 5 Remove brake shoes and inspect linings for excessive wear grease loose rivets or other damage Install new lining if old shows excessive wear or is saturated with grease or brake fluid 6 Inspect brake drums for scores run out or cracks If scores are not too deep or run out does not exceed 010 drums may machined If drums are badly scored or cracked they should be replaced 7 Inspect wheel cylinders for signs of fluid leakage or deteriorated rubber dust boots If brake fluid is leaking out of wheel cylin ders replace or recondition wheel cylinders 8 Clean grease and dirt off of backing plate and sand down shoe ledges of rusted or ridged 9 Apply a thin coating of suitable lubricant comparable to Lubriplate to shoe ledges 10 Thoroughly clean star wheel adjusting Screws pivot nuts hold down pins springs and cups Apply small amount of suitable lubricant comparable to Lubriplate to the threaded end of the a
74. d check for leakage out the top of the brake valve No leakage is permissible If leakage is found the brake valve must be replaced BRAKE VALVE Hand Operated Type HP Description Type HP brake valves Fig 5 are used for controlling the brakes on a trailer independent ly of the brakes on the towing vehicle They are usually mounted on the steering column or on the dash and the driver may put the handle in any one of several positions between brakes released and brakes fully applied position so the brakes on the trailer are kept applied until the brake valve handle is returned to release position The distance the brake valve handle is moved in a clockwise direction toward ap plied position determines the severity of the brake application The driver may therefore control the brakes on the trailer as the speed load and road conditions require PRESSURE REGULATING SPRING PISTON EXHAUST VALVE INLET VALVE BRAKE CHAMBER PORT 9356 INLET PORT Fig 5 Sectional View Of Hand Brake Value Donated by John amp Susan Hansen For Personal Use Only BRAKES AIR Section C L LINE MOTOR TRUCK SERVICE MANUAL Page 7 Testing for Serviceability Hand Brake Valve Operating Tests 1 Check the delivery pressure of the brake valve using anaccurate air pressure test gage The test gage may be conveniently con nected to the service line outlet at the rear of the vehicle With the br
75. der removal ment slot in backing plate 6 Lift out cylinder complete with connecting Note E Do not lubricate shoe adjustment links Be careful not to misplace spring mechanism or other parts of the brake washers 34 Lubrication will cause dust and dirt to collect and solidify in the adjustment III REMOVAL OF SHOE ADJUSTMENT mechanism MECHANISM Note When replacing shoes make sure 1 Remove shoes 2 from brake that shoe adjusting worm 10 Fig 2 is aligned with adjusting slot A or B 2 Rotate adjusting screw 7 threading it in backing plate Shoes 2 can be as free of worm wheel 12 sembled backward however the brake cannot be adjusted 3 Pry worm retainer snap ring 11 from shoe Note When replacing shoe retracting springs 4 End thrust washers 8 sleeve 9 worm 13 place hooked end on shoe pins at 10 and worm wheel 12 may now easily be shoe heel and then with brake spring removed pliers slip looped end of spring on hook at toe end adjustment end of IV WHEEL CYLINDER 21 DISASSEMBLY shoe 1 Pry off each boot retainer cap 33 Boot 32 and connecting link 35 will come with the cap Step By Step Procedure Assembly 2 Internal parts may now be forced out of one end of cylinder The brake is easily assembled in reverse order to disassembly 3 Slip cup back up ring segments 26 31 off of each piston assembly 23 28 V WHEEL CYLINDER ASSEMBLY 4 Cups 25 30
76. djusting screw and to contact points on the shoe webs ll When installing new shoes lay the shoes out in pairs according to their position on the truck The rear secondary shoe is the shoe with longer lining Donated by John amp Susan Hansen For Personal Use Only BRAKES ADJUSTMENTS L LINE MOTOR TRUCK SERVICE MANUAL Section F Page 3 12 Thread the star wheel adjusting screw into the pivot nut to the limit of the thread and assemble star wheel adjusting screw and adjusting screw spring to the adjustment end of the shoes with pivot nut against the right hand shoe NOTE Always assemble pivot nut on the right hand shoe regardless of position of shoes on the truck 13 Guide forked end of shoe links over anchor end of shoe web and attach shoes to backing plates by means of shoe hold down pins springs and cups 14 Attach retracting springs to shoes and anchor pins If springs show signs of having been overstressed they should be replaced 15 Install brake drums For lubrication and adjustment of front wheel bearings see Wheel Section NOTE DO NOT LOOSEN ANCHOR PINS UNLESS INSPECTION OF LINING TO DRUM CLEARANCE INDICATES A NEED FOR REPOSITIONING OF ANCHORS 16 Insert a 015 feeler gauge between the lining and drum of the rear secondary shoe about 1 1 2 from the star wheel adjusting screw end of the shoe and expand shoe by turning star wheel adjusting screw until feeler gauge cannot be withdrawn
77. e lining Adjusting hole cover Star wheel adjusting Adjusting screw screw Spring A 23054 Backing plate A 23055 Fig 3 Rear External View Fig 4 Rear Internal View PRINTED IN UNITED STATES OF AMERICA Donated by John amp Susan Hansen For Personal Use Only BRAKES ADJUSTMENTS Section F Page 2 Adjusting Screw Adjusting 1 tool Fig 5 A 22939 BRAKE ADJUSTMENT INSTRUCTIONS Before attempting to make any brake adjust ments whether minor or major be sure that wheel bearings are properly adjusted and that brake backing plates are tight Adjustment for Wear Minor PERFORM OPERATIONS IN SEQUENCE GIVEN AT BOTH FRONT AND REAR BRAKES UN LESS OTHERWISE NOTED NOTE 1 Place parking brake lever in fully released position 2 Jack up truck until the wheels are free from floor 3 Remove adjusting hole covers 4 Insert screw driver or special adjusting tool in slot of backing plate to engage star wheel adjusting screw Fig 5 5 Move outer end of screw driver or special tool toward axle expanding brake shoes to the point where the wheel can just be turned hand L LINE MOTOR TRUCK SERVICE MANUAL 6 Back off adjusting screw 12 to 14 notches and then check to see that brake drum turns freely It may be necessary to tap the back ing plate lightly to permit the brake shoes to take a central position 7 Replace adjusting hole covers Major Adjustments an
78. e F Adjustment Lining to drum clearance adjustment is required when shoes are relined and on occasion to compensate for normal lining wear Clearance should be sufficient to avoid brake drag and yet close to afford a good pedal reserve Manually operated and vacuum hydraulic actuated brakes require adjustment or relining when pedal reserve approximates 2 that is when the brake pedal drops to within 2 of floor board on hard application Adjustment may be made with the vehicle resting on jacks On jacks brake drag is checked by feel rotating the drum in the direction of for ward rotation as adjustment is made Step By Step Procedure Adjustment 1 Make all adjustments with drums cool 7 Donated by John amp Susan Hansen For Personal Use Only L LINE MOTOR TRUCK SERVICE MANUAL BRAKES ADJUSTMENTS Section J Page 5 2 Make sure wheel bearing is correctly ad justed 3 Place wrench 5 8 cam and shoe guide stud A or B Figs 1 and 4 to adjust Shoe Rotate wrench in the direction of FORWARD wheel rotation to decrease lin ing to drum clearance Reduce clearance until lining drags on drum 4 Move wrenchslightly in opposite direction to increase clearance until drag is re lieved Then move wrench slightly 79 to 109 to increase the working clearance 1 to 1 1 2 movement through arc swung by 8 wrench 5 Place wrench on opposite cam and shoe guide stude B o
79. e air brake System Hose Hose Fittings Hose Couplings and Dummy Couplings Flexible hose lines and hose fittings are used where 11 15 necessary to have an air line between two points of the vehicle which change their position in relation to one another Hose lines also make connections between two ve hicles and in such cases they are provided with hose couplings to permit the connections to be easily connected or disconnected Dummy couplings seal the hose couplings against the entrance of dirt when the hose couplings are not in use Dummy couplings on the back of tractor cabs also provide a place for attaching the free ends of connecting hose that is not being used Safety Valve The safety valve protects the air brake system against excessive air pressure Reservoirs Reservoirs store the compressed air until it is needed for brake operation and provide sufficient air pressure to make several brake applications even after the engine has stopped Air Gage The air gage mounted on the instrument panel of the vehicle registers the pressure in the air brake system Donated by John amp Susan Hansen For Personal Use Only BRAKES AIR Section C Page 2 L LINE MOTOR TRUCK SERVICE MANUAL INTERNATIONAL Air Supply Valve In some cases the air supply valve is in cluded to provide an easy means of obtaining compressed air from the air brake system for such purposes as tire inflation Low Pres
80. e floor board on hard application Adjustment may be made with the vehicle resting on jacks On jacks brake drag is checked by feel rotating the drum in the direction of for ward movement as the adjustment is made Step By Step Procedure Adjustment FR 2 Brake Figs 1 and 7 1 Make all adjustments with drum cooled to normal temperature 2 Make sure wheel bearing is correctly ad justed 3 Remove adjustment slot covers 4 Insert special adjusting tool or screwdriver into adjustment slot A or B to contact the star wheel Rotate star wheel toward axles using outer edge of slot as fulcrum for tool handle until lining drags the drum 5 Back lining off drum by rotating star wheel TWO notches away from axle This will provide sufficient working clearance 6 Repeat Steps 4 and 5 on Second shoe B or A 7 Replace adjustment slot covers Donated by John amp Susan Hansen For Personal Use Only L LINE MOTOR TRUCK SERVICE MANUAL BRAKES ADJUSTMENTS Section K Page 11 Step By Step Procedure Adjustment Type FR 2S Brake Figs 3 and 8 1 Make all adjustments with drum cooled to normal temperature 2 Make sure wheel bearings are correctly adjusted 3 Insert brake adjusting wrench Figs 3 and 8 through adjusting hole A or B in dust shield to fit firmly in adjusting worm Rotate wrench in direction of forward wheel rotation until lining drags on the drum 4 Rot
81. e greater equalization of brake lining pressure on the entire width of the drum surface more rapid heat dissipation and longer lining and drum life Dual shoes also simplify and yet permit greater accuracy of adjustment when compensating for lining wear Adjusting mechanisms are similar to the ad justment mechanism on type FR 2 Each ad justing screw is threaded into worm wheel placed in a slot located in its support The worm wheel is engaged with a worm which is rotated to effect adjustment The worm is en closed in a removable sleeve and worm and sleeve are held in the support by a thrust washer and a retainer snap ring Adjustments are made by inserting a 3 8 hex wrench in the worm and turning in the proper direction for the de sired adjustment The worm rotates the worm wheel which in turn threads the adjusting screw in the direction which the wrench is turned When the brakes are applied the wheel cylinder pistons apply force against the toe and heel of each shoe As the shoe linings come into contact with the drum self energization develops The rotation of the drum pulls the shoes against the drum surface to multiply the forces exerted on the drum and produce additional braking action If the vebicle is in forward motion this self energization or wrapping action pushes the shoe heels against the anchor pins In back ward motion the shoe toes are forced against the adjusting screws which then serve as anchor pins
82. e is located in the hydrovac slave cylinder end the brake pedal L LINE MOTOR TRUCK SERVICE MANUAL must be allowed to snap back QUICKLY to be released position This rapid return of the pedal and master cylinder piston allows the master cylinder barrelto receive brake fluid from the master cylinder reservoir on the return stroke and not just draw fluid back out of the lines when the pedal is released Continue bleeding until all of the air is expelled close bleeder valve Repeat bleeding operation at bleeder valve No 2 making sure the master cylinder fluid reservoir is kept full of brake fluid 4 Bleed the wheel brake cylinders in any con venient order NOTE Fluid withdrawn in the bleeding operation should not be used again Lubrication It has been definitely established that lubrication is highly important in hydrovac maintenance and that neglectofthis service adversely affects performance Hydrovacs should be lubricated as follows l Single piston 6 3 4 diameter hydrovacs should be lubricated once a year prefer ably before cold weather or every 20 000 miles whichever occurs first 2 Single piston 9 1 2 diameter hydrovacs should be lubricated every six 6 months or every 10 000 miles whichever occurs first One of these lubrication periods should occur just prior to the start of cold weather 3 The tandem piston hydrovacs should be lu bricated once a year preferably before cold weather orever
83. e the governorairstrainer and wash all parts in cleaning solvent Lamb s wool in the air cleaner may be used again if it can be washed thoroughly clean in cleaning solvent otherwise it must be replaced Every Year Or After Each 25 000 Miles a Disassemble governor and clean all parts b Cleanor replace both tubing lines con nected to the governor Testing for Serviceability and Adjusting Operating Tests 1 With the engine running build up air pressure in the air brake system and observe at what pressure registered by the dash gage the governor cuts out stopping further com pression The governor must cut out between 100 and 105 pounds PRINTED IN UNITED STATES OF AMERICA 2 With engine running slowly reduce the air pressure in the air brake system by applying and releasing the brakes and observe at what pressure registered by the dash gage the governor cuts in and compression is re sumed The governor must cut in between 80 and 85 pounds 3 Before condemning or adjusting the pressure settings of the governor be sure the dash gage is registering accurately This may be done by using an accurate test gage to check the pressure registered by the dash gage 4 Whennecessary the pressure settings cut in and cut out pressures may be adjusted after removing the cover The pressure set tings are raised by loosening the adjusting screw lock nut and turning the adjusting screw clockwise viewed from the top Fig
84. earances PRINTED IN UNITED STATES OF AMERICA Donated by John amp Susan Hansen For Personal Use Only L LINE MOTOR TRUCK SERVICE MANUAL BRAKES ADJUSTMENTS Section E Page 3 NOTE If anchor pin nut is loosened too much the anchor pin may shift when tightening the locknut 19 Replace adjusting hole covers Donated by John amp Susan Hansen For Personal Use Only Donated by John amp Susan Hansen For Personal Use Only BRAKES L LINE MOTOR TRUCK SERVICE MANUAL nidi cer Page 1 HYDRAULIC BRAKES BRAKE SHOE ADJUSTMENTS AND SERVICING 3135 1 135 1 132 i Pd oon Anchor pin Connecting link Retracting spring Wheel cylinder Anchor pin abes iius 9 Bleeder valve gc Retracting spring Backing 6 9 m 5 p We plate lt gt 1 Brake shoe S uer t A Hold down B ries spring and shoe oy Hold down ff and E ee 4 S shoe A A Brake shoe Backing ZA NN P una Pre e lining plate dh hole cover udi 7 z aX d Adjusting Adjusting screw Fig Front External View screw spring A 22938 Fig 2 Front Internal View h leed I Wheel cylinder Anchor pin Anchor pin Bleeder valve E Backin Ease Retracting spring 2 Brake shoe Brake shoe hold down spring and amp cup Be ET ibm i Brake sho
85. echanism When replacing shoes make certain that the toe or cutaway end of each shoe is aligned with the adjusting Screw and the heel of each shoe with the anchor pin otherwise adjust ments cannot be made When replacing shoe retracting springs place the straight ends of the springs in the notched holes in the brake shoes and with a brake spring pliers slip the looped ends over the pin or anchor pin projection as required The FR 2 type retracting springs are of equal length and loop over a pin mounted in the anchor and adjusting support Each shoe on the FR 2S and the FR 2SD type brakes has one long toe spring which loops over a pin mounted on a centered location on the spider and one short heel spring which loops over a projection on the anchor Pin Step By Step Procedure Assembly The brakes are easily assembled in reverse order to disassembly V TO ASSEMBLE WHEEL CYLINDERS 1 Do not assemble parts dry Coat parts and inside of cylinder bore with clean brake fluid before assembly 5 ADJUSTMENTS Section K Page 10 2 Stretch cups into place on the pistons lip must face inward toward spring groove side of piston Slip cup protector segments into place on each piston Protector segment is placed behind cup with segment lip facing same direction as cup lip Slide pistons with spring between them into cylinder chamber Be sure long stroke piston and short stroke piston a
86. erly adjusted b Air in system Remedy a Consult remedy b under No l b Consult remedy d under No 1 6 EXCESSIVE PRESSURE ON PEDAL POOR STOP Cause a Brake shoes not properly adjusted b Improper lining c Oil in lining d Lining making partial contact Remedy a Consult remedy b under No 1 b Specified linings have been developed to give satisfactory service and no changes should be made in the field to other makes of linings c Replace shoes d Remove high spots PRINTED IN UNITED STATES OF AMERICA Donated by John 8 Susan Hansen For Personal Use Only Donated John 4 Susan Hansen For Personal Use Only BRAKES L LINE MOTOR TRUCK SERVICE MANUAL POWER Page 1 HYDROVAC POWER BRAKE SYSTEM Cylinder shell Atmosphere control line o I Clamp bolt Bleeder valve Trailer brake connection plug End plate Control valve Atmosphere inlet from air cleaner Lock nut Ble der valve r e Stabilizing support stud holes Outlet to Inlet from master Vacuum inlet from wheel cylinders Slave cylinder cylinder vacuum source A 19444 Fig Exterior View of Third Series C Series Single 6 3 u Diameter Piston Hydrovac No 474000 Fig 2 illustrates the Interior Details of the Above Unit 2 a Control valve piston Atmosphere control 7 Bleeder valve line Q MN 00 Diaphragm Vacu
87. ermit the brake shoes to take a central position 8 Replace adjusting hole covers Major Adjustments and Servicing Figs 1 2 3 4 and 5 The following adjustments are performed only when adjustments under Minor Adjustments fail to give satisfactory results or when in stalling new shoes or linings PERFORM OPERATIONS IN SE QUENCE GIVEN AT BOTH FRONT AND REAR BRAKES UNLESS OTHER WISE NOTED NOTE 1 Place parking brake lever in fully released position 2 Jack up truck until wheels are free from floor 3 Remove wheels hubs and drums 4 Remove adjusting hole covers 5 Remove brake shoes and inspect linings for excessive wear grease loose rivets or other damage Install new lining if old lining shows excessive wear or is saturated with grease or brake fluid 6 Inspect brake drums for scores run out or cracks If scores are not too deep or run out does not exceed 010 drums may be machined If drums are badly scored or cracked they should be replaced 7 Inspect wheel cylinders for signs of fluid leakage or deteriorated rubber dust boots If brake fluid is leaking out of wheel cylin ders replace or recondition wheel cylinders 8 Clean grease and dirt off of backing plate and sand down shoe ledges if rusted or ridged 9 Apply a thin coating of suitable lubricant comparable to Lubriplate to all shoe ledges 10 NOTE 11 12 13 14 155 16 17 18
88. essed they should be replaced 15 Install brake drums For lubrication and adjustment of front wheel bearings see Wheel Section NOTE DO NOT LOOSEN ANCHOR PINS UNLESS INSPECTION OF LINING TO DRUM CLEARANCE INDICATES A NEED FOR REPOSITIONING OF ANCHORS 16 Insert a 015 feeler gauge between the 17 18 lining and drum of the rear secondary shoe about 1 1 2 from the star wheel ad justing screw end of the shoe and expand shoe by turning star wheel adjusting screw until feeler gauge cannot be withdrawn Then turn star wheel adjusting screw in opposite direction until there is but a light drag on the feeler gauge Withdraw feeler gauge NOTE Expanding shoes until feeler gauge cannot be with drawn insures that shoes are resting against the anchor pin Revolve brake drum so that feeler gauge hole is about 1 1 2 from the anchor end of the rear secondary shoe lining There should be a slightly heavier drag on the feeler gauge at this point If the clearance at the anchor end of the shoe is greater than the clearance at the adjustment end by 003 or more it will be necessary to ad just the anchor pin To adjust anchor pin loosen locknut 1 4 to 1 2 turn and tap anchor pin either up or down to provide the correct anchor pin position After positioning the anchor pin to provide the correct rear secondary shoe clearance tighten the anchor pin lock nut with a 16 wrench and then recheck anchor and adjusting end cl
89. exceed 010 drums may be machined If drums are badly scored or cracked they should be replaced Inspect wheel cylinders for signs of fluid leakage or deteriorated rubber dust boots If brake fluid is leaking out of wheel cylinders replace or recondition wheel cylinders Clean grease and dirt off backing place and sand down shoe ledges if rusted or ridged Apply a thin coating of suitable lubricant comparable to Lubriplate toshoe ledges Thoroughly clean star wheel adjusting screws pivot nuts hold down pins springs and cups Apply a small amount of suitable lubricant comparable to Lubriplate to the threaded end of the adjusting screw and to contact points on the shoe webs 12 13 14 When installing new shoes lay th shoes out in pairs according to their position on the truck The rear secondary shoe is the shoe with longer lining Thread the star wheel adjusting screw into the pivot nut to the limit of the thread and assembly star wheel adjusting screw and adjusting screw spring to the adjustment end of the shoes with pivot nut against the right hand shoe NOTE Always assemble pivot nut on the right hand shoe regardless of position of shoes on the truck Guide forked end of shoe links over anchor end of shoe web and attach shoes to backing plates by means of shoe hold down pins springs and cups Attach retracting springs to shoe and anchor pins If springs show signs of having been overstr
90. fluid with mineral base into the system will cause the cups to swell and distort making it necessary to replace all cups and flush system b Directly ahead of the master cylinder piston cup when in normal release position is a relief port It is im perative that this port be open when the brakes are released Brake pedal should be set to give the proper free movement before pressure stroke begins Should this port be blocked by piston cup not returning to its proper release position the pressure in the system will L LINE MOTOR TRUCK SERVICE MANUAL 3 gradually build up and brakes drag Shorten pedal push rod to allow piston to uncover compensating port allowing fluid to return to tank ONE WHEEL DRAGS Cause a Weak brake shoe return spring b Brake shoe set too close to drum c Cups distorted d Loose wheel bearings Remedy a Springs sometimes lose their con tracting power and take a set Replace spring b Readjust shoes to proper clearance Do not change anchor pin setting unless necessary c Ifin repairing wheel cylinders kero sene gasoline and other fluids are used as a cleaner instead of alcohol the cups will swell and distort The return action of the shoes will be retarded and the brake drum will heat Replace cups and wash unit in alcohol and dip all parts in fluid before reassembling d Tighten bearings TRUCK PULLS TO ONE SIDE Cause a Grease soaked lining
91. g power The fact that these brakes incorporate the greatest pos sible use of self energization in drums of the same or smaller sizes than those now in use is of tremendous importance in solving the braking problems of medium and heavy duty trucks The basic design of these brakes is the same The FR 2 and the FR 2S each incorporate two identicai shoes and two identical wheel cylinders The major difference is that the FR 2 uses a backing plate while the FR 2S is mounted on a spider The FR 2SD is a dual type brake equipped with four shoes Its appearance is comparable to two FR 2S brakes placed back to back and it employs two Siamese T win type Donated by John amp Susan Hansen For Personal Use Only BRAKES ADJUSTMENTS Section K Page 8 L LINE MOTOR TRUCK SERVICE MANUAL wheel cylinders to actuate the dual shoes The shoes of all these brakes are arranged with the toes diagonally opposite each other and the double end wheel cylinders are placed between the toe of one shoe and the heel of the other An equal amount of hydraulic pressure is thus applied at each end of each shoe Shoes are always forward acting independently actuated in the direction of rotation Shoes anchor at either toe or heel depending upon the rotation of the drum The 2 brake is constructed for use the rear axle of medium weight trucks and buses AS previously mentioned the major difference of this brake from the other two is that t
92. ge is found the compressor cylinder head or complete compressor should be repaired or replaced Trouble Shooting Dirty intake strainer Excessive carbon in com pressor cylinder head or discharge line Discharge valves leaking Compressor fails to maintain adequate pres sure in the air brake system Excessive wear Drive belt slipping No clearance at compressor unloading valves Unloading valves stuck open Excessive leakage of unload ing valves Excessive wear Dirty air strainer Excessive oil pressure Oil returnline or passage to Compressor engine crankcase plugged passes exces sive oil Compressor crankcase flooded Back pressure from engine crankcase Oil rings improperly in stalled Back lash in drive coupling or drive gears Loose drive pulley Excessive carbon incylinder head or discharge line Noisy operation Worn or burnt out bearings Excessive wear Defective unloading dia phragms Excessive clearance at un Compressor loading valves does not unload Unloading cavity plugged with carbon Unloading mechanism bind ing or stuck PRINTED IN UNITED STATES OF AMERICA Donated by John amp Susan Hansen For Personal Use Only L LINE MOTOR TRUCK SERVICE MANUAL BRAKES AIR Section C Page 5 BRAKE VALVE See Fig 3 Description The brake valve is fitted with a lever suit able for connecting to the brake pedal The pedal controls t
93. h drawn insures that shoes are resting against the anchor pin Revolve brake drum so that feeler gauge hole is about 1 1 2 from the anchor end of the rear secondary shoe lining There should be a slightly heavier drag on the feeler gauge at this point If the clearance at the anchor end of the shoe is greater than the clearance at the adjustment end by 003 or more it will be necessary to adjust the anchor pin To adjust anchor pin loosen lock nut 1 4 to 1 2 turn and tap anchor pin either up or down to provide the correct anchor pin position After positioning the anchor pin to provide the correct rear secondary shoe clearance tighten the anchor pin lock nut with a 16 wrench and then recheck anchor and adjusting end clearances NOTE If anchor pin nut is loosened too much the anchor pin may shift when tighten ing the lock nut To adjust rear parking brake cables ex pand shoes at both rear brakes until tight against brake drums With parking brake lever applied approximately 1 from fully released position pull cables by hand to remove all slack Adjust cables as re quired at yoke ends so that clevis pin can be inserted Insert clevis pins and new cotter pins At both rear brakes back off star wheel adjusting screw 12 to 14 notches To check rear brakes for balance pull park ing brake lever back until rear wheel can just be turned by hand Check rear wheels for even brake drag If drag is uneven loosen the t
94. h of the shoe adjusting worms Jpon brake application the wheel cylinder pistons 23 and 28 Fig 2 apply force against toe and eel of each shoe Upon contact of shoe liners 5 with the drum self energization shoe wrap ing action caused by drag of the drum on the inings wraps both shoes into the drum If the PRINTED IN UNITED STATES OF AMERICA vehicle is moving forward the shoe heels are wrapped against their anchor blocks by the drum rotation If the vehicle is backing the shoe toes are forced against their anchor blocks Anchor block sides are aligned on the axle radius Upon contact with the anchor blocks the shoes pivot and at the same time move radially along the anchor block sides until they are centered in relation to the drum Self energization assists brake application equally regardless of the direction of the drum rotation T he brake is thus capable of develop ing the same maximum torque output for a re verse stop that is used for a forward stop and it is always automatically self centering Disassembly The first disassembly operation is al ways removal of brake shoe retracting springs 13 Fig 2 With brake Spring pliers slip looped end of spring off of the spring hook located at the toe or adjustment end of each shoe Note A Note B If wheel cylinder connecting tube 39 and bleeder valves 38 are re moved mark wheel cylinder ports to which connecting tube is attached to avoid error in re
95. he air in the brake chambers to escape quickly at the quick release valve On some trucks air is released from the front wheel brake chambers back through the lines to the foot brake valve and exhausted at that point Where this is the case the quick release valve housing installed at the front of the vehicle serves merely as a connector and does not contain either a diaphragm or dia phragm spring and the exhaust opening in the quick release valve housing is closed with a plug IMPORTANT DO NOT REMOVE THIS PLUG TO DO SO WILL RENDER THE FRONT WHEEL BRAKES INOPERATIVE Leakage Tests 1 With brakes released coat the exhaust port with soapsuds to determine leakage 2 With the brakes fully applied coat the exhaust port with soapsuds to determine leak age Donated by John amp Susan Hansen For Personal Use Only BRAKES AIR Section C Page 8 3 Leakage in excess of a one inch soap bubble in one second 15 notpermissible in either of these tests If excessive leakage is found the relay valve must be repaired or replaced DOUBLE CHECK VALVE Description double check valve is used on the tractor truck at the frame side rail Fig 7 It is con nected into the air lines from the relay valve to the trailer lines The purpose of the double check valve is to control the brakes on the trailer or towed load If the double check valve were not used when one of the brake valves was moved to its applied position ai
96. he as sembly is mounted ona backing plate Riveted to this backing plate are two anchor and adjust ing supports Into each anchor and adjusting support is placed on anchor pin at one end of the support and a star wheel and adjusting screw at the other end The adjusting mechanism is assembled as follows The adjusting screw is threaded into its end of the support the star wheelis placed in the slot of the support so that the keys inside of the wheel fit into the lengthwise grooves of the adjusting screw the star wheel being held in the correct adjustment position by a lockspring Adjustments are made through a slot in the backing plate opposite the star wheel by placing the special adjusting tool or screwdriver through the slot and turning the star wheel to achieve the desired adjustment The FR 2S is constructed for the front axles of vehicles having a gross weight of 30 000 to 45 000 lbs and is used in conjunction with the FR 2SD rear axle brake These brakes are mounted on malleable iron spiders the FR 2S single sided spider and the FR 2SD on a double sided spider The adjusting and anchor support on these brakes is cast as an integral part of the spider The principle adjustment difference is that the adjusting screw is operated by worm and worm wheel instead of a star wheel The FR 2SD is designed with four shoes two on each side of the spider These four shoes offer advantages over two wide shoes in that they provid
97. he movement of an inlet valve and exhaust valve which in turn controls the air pressure being delivered to or released from the brake chambers on the vehicle To fully apply the brakes the brake pedal must be fully depressed whereas when the pedal is only partially depressed correspondingly less braking force is developed In other words Lever Roller Adjusting me screw Lock nut Air outlet to front brake Outlet chambers to check valve Air outlet to rear brake chambers Air inlet from reservoir Ses KIA 22832 Fig 3 Brake Valve the farther the driver depresses the pedal the greater the airpressure delivered to the brake chambers and the more effective the brake ap plication At any time the brakes of the vehicle may be partially released by the driver mitting the brake pedal to partially return towards released position or they may be en tirely released by permitting the pedal to re turn to full released position In this manner the amount of force being applied to the brakes of the vehicle is always under control of the driver Preventive Maintenance Every Month or After Each 2 000 Miles a Lubricate all linkage between the brake valve and brake pedal also lubricate the brake valve lever pin b Check to be sure that no strain is placed on the brake valve lever because the lower edge of the lever cap strikes the cover when the brake pedal is fullydepressed Adjust
98. heck clearances 020 to 030 clearance XI Tm T is E 0 20 to 0 30 7726052 clearance e e LI lt N Ney Ce 020 to 030 clearance 020 to 030 clearance A 22889 Fig 2 Donated by John amp Susan Hansen For Personal Use Only BRAKES ADJUSTMENTS Section M Page 2 PARKING BRAKE FOR L 190 AND LF 190 SERIES TRUCKS L 200 L 201 L 202 L 204 TRUCKS Parking Brake Adjustments See Fig 3 Note Perform operations in sequence given 1 Place parking brake in extreme forward release position NOTE Brake cam lever must rest squarely on the upper brake band bracket To correct this position remove clevis pin and readjust yoke The lining to drum clearance of 020 to 030 is obtained as follows Adjust anchor screw nut 1 until 020 to 030 clearance is obtained at side of the stop screw b Tighten nuts 4 on adjusting screw bracket bolt 5 to give 020 to 030 lining clearance to drum for lower half of shoe c Adjust upper half of shoe lining clearance to 020 to 030 by turning nut 2 on adjusting bolt 3 d Lock all adjustments and recheck clearances 020 to 030 clearance 1 020 to 030 020 to 030 SSS clearance L LINE MOTOR TRUCK SERVICE MANUAL AAA INTERNATIO
99. ic Brake Size Standard 6 wees 15x2 1 4x5 16 15x2 1 4x5 16 15x2 1 4x5 16 15x2 1 4x5 16 12x2 1 4x5 16 16 1 2x3 1 2x5 8 15 4 3 8 16 4 3 8 16 5 3 8 16 1 2x7 1 8x5 8 16x5x3 8 16 1 2x7 1 8x5 8 Brake Size Increased Capacity Front Same 5 Standard 15x2 1 4x5 16 15x2 1 4x5 16 15 2 1 4 5 16 RGAE ar aere wa Od 15x5x3 8 16x5x3 8 16x6x3 8 Number of Shoes s 53433 45924 2 2 2 2 pele gt Type of Anchor Eront a Double Double Rear A woes l e Double Double Wheel Cylinder Size Standard EIOBL 33 4 1 1 4 1 1 4 Double 1 1 4 1 1 4 1 1 4 1 1 2 Rear sa 11 2 1 5 8 1 3 4 I Wheel Cylinder Size Increased Capacity Front Same as Standard 1 1 4 1 1 4 1 1 4 1 1 4 nm Number of Wheel Cylinders Standard Fronts 2 2 2 2 e kus a eos a 2 Siamese Twir type 2 Siamese Twin type Number of Wheel Cylinders Increased Capacity Front Same as Standard 2 2 7 ou qq UU eS a 2 j 0 02 Jj 2 j e J 2 Master Cylinder Size Bore and Stroke 1 3 4x2 1 2 1 3 4x1 7 16 1 3 4x1 7 16 1 3 4x2 1 2 1 3 4x2 1 2 I Barre Hydrovac Standard or Optional Standard Standard Standard S
100. ight brake to provide even drag Replace adjusting hole covers Donated by John amp Susan Hansen For Personal Use Only Donated John 4 Susan Hansen For Personal Use Only BRAKES ADJUSTMENTS Section H L LINE MOTOR TRUCK SERVICE MANUAL 1 VV HYDRAULIC BRAKES BRAKE SHOE ADJUSTMENTS AND SERVICING FRONT 12 1 8 x 2 REAR L 150 LM 150 LM 1511 14 2 1 4 Backing plate I Brake shoe web Brake shoe Backing plate pnm hold down Wa Bleeder Pte g spring and Wheel cylinder 4 GC s SUP 7 w pb Brake shoe 7 rn um hold down E M va Anchor U 3 tar wheel pin N AME adjusting Connecting ER link Brake shoe lining Adjusting screw i Spring 4 23065 Adjusting hole cover A 23066 Fig 2 Front Internal View Fig Front External View Anchor pin 4 Backing plate Wheel cylinder Brake shoe Connecting link Retracting spring 2 Bleeder valve Anchor pin TTL Brake shoe hold down spring and cup A B t 2 gt z NT Y 5 pA iare Brake shoe Z lining A N e Backing plate Adjusting hole cover Star wheel adjusting nnns screw A 23055 screw SPUDE 23054 Fig 4 Rear Internal View Rear External View PRINTED IN UNITED STATES OF AMERI
101. in the compressor cylinder head stops starts the compression ofairbythe compressor when the desired max imum and minimum air pressures are present in the air brake system Brake Valve The brake valve controls the air pressure being delivered to the brake chambers and in this way controls the operation of the brakes Quick Release Valve The quick release valve speeds the release of air pressure from the front wheel brake chambers Relay Valve The relay valve speeds the application and release of air pressure from the rear wheel brake chambers Brake Chambers and Brake Cylinders Brake chambers and brake cylinders trans form the energy of compressedair into the me chanical force and motion necessary toapplythe brakes One brake chamber or one brake cylin der isused to operate the brakes on each wheel PRINTED IN UNITED STATES OF AMERICA Slack Adjusters Slack adjusters provide a quick and easy method of adjusting the brakes to compensate for brake lining wear One slack adjuster is used for the brakes on each wheel Cocks Cut out cocks are used in the trailer con nection lines to permit these lines to be closed when they are not being used Reservoir drain cocks are used also mounted at the bottom of the reservoir The drain cocks permit drain ing the oil and water which collects in the res ervoir Tubing and Tubing Fittings Tubing and tubing fittings connect the different air brake devices in th
102. ing brake cable adjustment should be made at this time With brake shoes still expanded disconnect the parking brake cable at the intermediate lever end With parking brake lever applied approximately 1 from fully released position pull cables by hand to remove allslack Adjust cables as required at yoke ends so that clevis pins can be in serted Insert clevis pins and new cotter pins 7 Back off star wheel adjusting screw 12 to 14 notches and then check to see that brake drum turns freely may be necessary to tap the backing plate lightly to permit the brake shoes to take central position 8 Rear brakes only Pull parking brake lever back until the rear wheel can just be turned by hand Check rear wheels for even brake drag If drag is uneven loosen the tight brake to provide even drag 9 Replace adjusting hole covers Major Adjustments and Servicing Figs 1 2 3 4 and 5 The following adjustments are performed only when adjustments under Minor Adjustments fail to give satisfactory results or when install ing new shoes or linings NOTE Perform Operations in Sequence Given At both front and rear brakes unless otherwise noted 1 Place parking brake lever in fully released position 2 Jack up truck until wheels are free from floor 3 Remove wheels hubs and drums 4 Remove adjusting hole covers 5 Remove brake shoes and inspect linings for excessive wear grease loose rivets or o
103. into glass and carries with it any air which might be present in the system Watch flow of fluid from tube the end of which should be kept below sur face of fluid in pint bottle and when all air bubbles cease toappearor when streamisa solid fluid mass close bleeder valve See Fig 5 Fluid withdrawn in bleeding operation should not be used again unless absolutely certain that it does not contain impurities Fluid of PRINTED IN UNITED STATES OF AMERICA Fig 5 which the cleanliness is questionable should never be used Fluid should be replenished in supply reservoir after each cylinder is bled Should supply reservoir be drained during bleed ing operation air will enter the system and bleeding will then be necessary Maintenance Hints 1 PEDAL GOES TO FLOOR BOARD Cause a Normal wear of lining b Brake shoes not properly adjusted c Leak in system d Air in system e Pedal improperly set f No fluid in supply reservoir When brake linings become worn it is necessary to set the shoes into closer relation to brake drums This condition is usually accompanied by the remark that it is necessary to pump the pedal several times before a brake is obtained Shoes should be set in accordance with instructions on ADJUSTMENTS FOR WEAR Donot disturbanchor pins when making this adjustment Adjustment must be made while drums are cool Donated by John amp Susan Hansen For Personal Use
104. ions interconnecting the master cylinder and wheel cylinders The master cylinder and wheel cylinders are fitted with pistons all of which are provided with cup packings which act as a sealto maintain pressure and prevent loss of brake fluid Depressing the brake pedal moves the piston within the master cylinder thus displacing the brake fluid from the master cylinder through its outlet orifices tubing and flexible hose con nect ons into the wheel cylinders The brake fluid being noncompressible enters each of the wheel cylinders causing the cylinder pistons to move outward and actuate the brake shoes As pressure on the pedal is increased greater hydraulic pressure is built up within the wheel cylinders and consequently greater force is exerted against the shoes When the pressure on the pedal is released the brake shoe retracting springs return the brake shoes to their normal or released position The return movement of the brake shoes in turn causes movement of the wheel cylinder pistons toward their released position thus forcing the fluid back thru the tubing into the master cylinder Hydraulic Fluid Always use genuine Lockheed or other high grade automotive type brake fluid The use of other than genuine Lockheed or any high grade automotive type brake fluid or the introduction of mineral base oil into the system will cause rubber parts to swell and become inoperative Combination Type Master Cylinde
105. iston 5 Wheel driven adjusting worm Spring 6 Worm adjusting shoe Piston assembly short 7 Sleeve adjusting worm Piston short 8 Washer end thrust adjusting worm Cup piston 9 Ring snap worm retainer Protector segment cup piston 10 Shoe and lining assembly Boot assembly 11 Shoe Push rod 12 Lining Valve bleeder wheel cylinder 13 Rivet Cover wheel cylinder 14 Pin assembly shoe guide Bolt mounting wheel cylinder 15 Washer shoe guide pin Lockwasher cylinder mounting bolt 16 Clip spring shoe guide Tube assembly connecting wheel 17 Spring retracting shoe toe long cylinder 18 Spring retracting shoe heel short Bolt fitting inlet 19 Wheel cylinder assembly upper Gasket fitting inlet Wheel cylinder assembly lower Fitting inlet fluid 20 Body wheel cylinder upper Gasket bolt fitting Body wheel cylinder lower Dust shield assembly 21 Gasket port plug Bolt mounting dust shield 22 Screw port plug Lockwasher dust shield mounting bolt i A 22939 Fig 7 Brake Adjustment Type FR 2 Brake Brake lining N Brake adjusting wrench A 23450 Fig 8 Brake Adjustment Type 25 Brake PRINTED IN UNITED STATES OF AMERICA Donated by John amp Susan Hansen For Personal Use Only BRAKES ADJUSTMENTS L LINE MOTOR TRUCK SERVICE MANUAL Section K Page 7 eS s Dust shield
106. kage No leakage is permissible If leakage is found the stop light switch must be replaced DIAPHRAGM CONTACT POINTS NS TERMINALS NON AIR INLET A 9354 Fig 15 Sectional View Of Stop Light Switch BRAKE CHAMBER BENDIX WESTINGHOUSE The Bendix Westinghouse brake chamber consists of two dished metal plates namely the non pressure plate and the pressure plate separated by a diaphragm see Fig 16 Dust shield lt Push rod return spring Push rod A 22923 Fig 16 Typical Brake Chamber Diaphragm Type In frontof the diaphragmare the non pres sure plate push rod and push rod spring Be hind the diaphragm is the air tight cavity into which is connected a tubing line from the brake V valve Due to the extreme sensitivity of the diaphragm this arrangement permits push rod to respond to the slightest variation of air pres sure from the brake valve thus permitting the driver to apply or release brakes as rapidly or gradually as the various road and operating conditions warrant Inorderto meetrequirements for different braking forces brake chambers are made in severaldifferentsizes All sizes are made for several different types of mountings such as stud mounting bracket mounting and flange mounting The following table shows different types of standard brake chambers Maxi mum Maxi e Effective Normal
107. lace adjusting hole covers PERFORM THE FOLLOWING OPER ATIONS AT EACH REAR WHEEL SEE FIGS 2 AND 3 When installing new shoes lay the shoes out in pairs according to their position on truck The rear secondary shoe is the shoe with longer lining Thread the star wheel adjusting screw into the pivot nut to the limit of the thread and assemble star wheel adjusting screw and adjusting screw spring to the adjustment and of the shoes with pivot nut against the right hand shoe NOTE Always assemble pivot nut on the right hand shoe regardless of position of shoes on the truck Guide forked end of shoe links over anchor end of shoe web and attach shoes to backing plates by means of shoe hold down pins Springs and cups Attach retracting springs to shoes and anchor pin If springs show signs of having been overstressed they should be replaced Install brake drums DO NOT LOOSEN ANCHOR PINS UNLESS INSPECTION OF LINING TO DRUM CLEARANCE INDICATES A NEED FOR REPOSITIONING OF ANCHORS Insert a 015 feeler gauge between the lining and drum of the rear secondary shoe about 1 1 2 from the star wheel ad justing screw end of the shoe and expand shoe by turning star wheel adjusting screw until feeler gauge cannot be withdrawn Then turn star wheel adjusting screw in opposite direction until there is but a light drag on the feeler gauge Withdraw feeler gauge NOTE Expanding shoes until feeler gauge cannot be withdrawn insu
108. lease the brakes by hastening the exhaust of air pressure from the brake chambers It is most commonly used with front wheel brake chambers The valve consists of a body containing a spring loaded diaphragm so arranged as to per mit air pressure to flow through the valve in one direction but when the supply pressure is reduced the air which has passed through the valve is permitted to escape through the ex haust port Fig 6 PRINTED IN UNITED STATES OF AMERICA INLET PORT DIAPHRAGM BRAKE CHAMBER X ilk PORT COVER EXHAUST PORT A 9360 Fig 6 Sectional View Of Quick Release Valve Operating Tests Apply the brakes and observe that when the brakes are released air pressure is quickly exhausted through the exhaust port of the valve Be sure the exhaust port is not restricted in any way The valve must be tested at regular inter vals for leakage by applying soapsuds on the exhaust port with the brakes applied On re leasing the brakes see that the valve releases immediately with the corresponding return movement of the foot pedal Leakage may be caused by dirt in the valve or a defective dia phragm As a rule the diaphragm should be replaced at least once every year The air line from the brake valve to the rear wheel chambers is released back to the quick release valve This allows the diaphragm in the quick release valve to unseat uncovering the exhaust port in the valve and permitting t
109. lining to drum clearance of 020 to 030 is obtained as follows a Adjust anchor screw nut 1 until 020 to 030 clearance is obtained at side of the stop screw b Tighten nuts 4 on adjusting screw bracket bolt 5 to give 020 to 030 clearance between lower half of lining and drum c Adjust lining clearance for upper half of band to 020 to 030 by turning nut 2 on adjusting bolt 3 d Lock all adjustments and recheck clearances 020 to 030 clearance 020 to 030 clearance 9 lt 2 020 to 030 clearance A 22888 Fig PRINTED IN UNITED STATES OF AMERICA PARKING BRAKE FOR L 180 LC 180 SERIES TRUCKS Parking Brake Adjustments See Fig 2 Note Perform operations in sequence given 1 Place parking brake lever in extreme for ward release position NOTE Brake cam lever must rest squarely on the upper brake band bracket To correct this position remove clevis pin and readjust yoke The lining to drum clearance of 020 to 030 is obtained as follows a Adjust anchor screw nut 1 until 020 to 030 clearance is obtained at side of the stop screw b Tighten nuts 4 on adjusting screw bracket bolt 5 to give 020 to 030 clearance between lower half of lining and drum c Adjust lining clearance for upper half of band to 020 to 030 by turning nut 2 on adjusting bolt 3 d Lock all adjustments and rec
110. lose toafford a good pedal reserve Manually operated and vacuum hydraulic actu ated brakes require adjustment or relining when pedal reserve approximates 2 that is when the brake pedal drops to within 2 of the floor board on hard application Adjustment may be made with the vehicle resting on jacks On jacks brake drag is checked by feel rotating the drum in the direction of for ward rotation as adjustment is made Step By Step Procedure Adjustment 1 Make alladjustments with drum cooled to normal temperature 4 Make sure wheel bearing is correctly ad justed 3 Remove adjustment slot covers 4 Insert brake adjusting wrench in adjust ment slot A or B Figs l and 3 to contact shoe adjusting worm 10 Rotate wrench in the direction of FORWARD wheel rota tion to decrease lining to drum clearance Reduce clearance until lining drags on drum 5 Rotate wrench in opposite direction to in crease clearance until drag is relieved Then rotate wrench one additional turn to provide working clearance 6 Repeat Steps 4 and 5 on the second shoe Adjustment Slot B or A 7 Replace adjustment slot covers Donated by John amp Susan Hansen For Personal Use Only BRAKES L LINE MOTOR TRUCK SERVICE MANUAL Page 6 BLEEDING THE HYDRAULIC BRAKE SYSTEM Vehicle brake systems using the self centering hi tork foundation brake are bled in similar manner to other hydraulic system
111. ls are free from floor Remove adjusting hole covers Insert screwdriver or special adjusting tool in slot of backing plate to engage star wheel adjusting screw Fig 5 Move outer end of screwdriver or special tool toward axle expanding brake shoes to the point where the wheel can just be turned by hand L LINE MOTOR TRUCK SERVICE MANUAL 7 INTERNATIONAL Back off star wheel adjusting screw 12 to 14 notches and then check to see that brake drum turns freely It may be necessary to tap the backing plate lightly to permit the brake shoes to take a central position Replace adjusting hole covers Major Adjustments and Servicing Figs 1 2 3 4 and 5 The following adjustments are performed only when adjustments under Minor Adjustments fail to give satisfactory results or when in stalling new shoes or linings NOTE 10 PERFORM OPERATIONS IN SE QUENCE GIVEN AT BOTH FRONT AND REAR BRAKES UNLESS OTHER WISE NOTED Place parking brake lever in fully released position Jack up truck until wheels are free from floor Remove wheels hubs and drums Remove adjusting hole covers Remove brake shoes and inspect linings for excessive wear grease loose rivets or other damage Install new lining if old lining shows excessive wear or is saturated with grease or brake fluid Inspect brake drums for scores run out or cracks If scores are not too deep or run out does not
112. lve H Hydraulic ie y A slave cylinder Atmosphere a T BS inlet ec from engine B air cleaner Control valve housing Lubrication plugs A 23204 Fig 5 Exterior View of Third Series C Series Tandem 9 1 2 Diameter Cylinder Hydrovacs No s 374229 and 374230 BLEEDER VALVE VACUUM INLET FROM 17 VACUUM SOURCE FAST APPLICATION 7 VALVE PA T e Co gt J BLEEDER VALVE INLET FROM 74 AIR CLEANER LAE 2 MENU SLAVE CYLINDER 4 WHEEL 2 CYLINDER wem RESIDUAL LINE Bu A ag T PRESSURE CHECK CONTROL VALVE E mu ce on VALVE JNLET FROM MASTER CYLINDER 10285 PISTON ROD CENTER PLATE 2 Fig 6 Sectional View of Third Series C Series Tandem 9 1 2 Diameter Cylinder Hydrovacs No s 374229 and 374230 PRINTED IN UNITED STATES OF AMERICA Donated by John amp Susan Hansen For Personal Use Only BRAKES HYDROVAC POWER Section B Page 4 HYDROVAC POWER BRAKE SYSTEM Bendix Hydrovacs Third Series Nos 374000 375278 375279 314229 and 374230 Hydrovac Power Brake Units Figs 1 2 3 4 5 6 The hydrovac is installed on vehicles having the conventional hydraulic brake system to make available to the operator a greater pressure on the hydraulic brake system than could be exerted by foot pressure alone Description The hydrovac is a hydraulic vacuum power braking
113. n Pad Pad d VDO mi N o FFON 45 3 ws 5 5 6 1 2 6 1 2 Be H Un M p O A p lt m et H C 09 p Model D 1 LF 230 LF 231 D 1 5 ss 6 amp z Foot Pedal Foot Pedal Air Reservoir Number Used 1 5 1 Length and Diameter 41 1 2x8 41 1 2 8 Air Compressor Type Westinghouse 2 Cyl 2 Cyl Capacity Cu Ft 7 1 4 7 1 4 es Water Mounting os a Engine Engine Drive sss sses Belt Belt L s ss Z lt O AJ E C aN Un T lt C T gt 2 C gt UC WALSAS Donated by John amp Susan Hansen For Personal Use Only L LINE MOTOR TRUCK SERVICE MANUAL Donated by John amp Susan Hansen For Personal Use Only BRAKES HYDRAULIC Section Page 1 HYDRAULIC BRAKES HYDRAULIC BRAKE SYSTEM The hydraulic system used to actuate the brake mechanism consists of a compensating type master cylinder in which the hydraulic pressure is originated individual wheel cylinders in which the hydraulic pressure is applied which serve to actuate the brake shoes against the brake drum of each wheel and the Line con sisting of steel tubing flexible hose brackets and un
114. n Adjusting screw 23066 Spring 4 23065 Fig Front External View Fig 2 Front Internal View Adjusting hale Bleeder valve EOM Backing plate Wheel cylinder Shield BE 8 nnecting link Brake shoe 80 Brake shoe web lining au mnis ME Retracting spring Retracting spring SUA black yellow ig 9 shoe Ii hold down washer V T 3 x 4 p 5 Retracting spring MON yellow Adjusting screw lock spring hydraulic line ON Retracting spring WAA black a Brake shoe anchor A Star wheel Bleeder valve trem bracket adjusting screw A 23067 Fig 3 Rear External View Fig Rear Internal View PRINTED IN UNITED STATES OF AMERICA Donated by John amp Susan Hansen For Personal Use Only BRAKES ADJUSTMENTS Section I Page 2 Brake shoe Adjusting screw Adjusting A 22939 Fig 5 BRAKE ADJUSTMENT INSTRUCTIONS Before attempting to make any brake adjust ments whether minor or major be sure that wheel bearings are properly adjusted and that brake backing plates are tight Adjustments For Wear Minor PERFORM OPERATIONS IN SE QUENCE GIVEN AT BOTH FRONT AND REAR BRAKES UNLESS OTHER WISE NOTED NOTE 1 Place parking brake lever in fully released position 2 Jack up truck until the wheels are free from floor 3 Remove adjusting hole covers PERFORM THE FOLLOWING AT EACH FRONT W
115. ndard PEON ok RR 12 1 8x2x1 4 12 1 8x2 1 4x5 16 12 1 8x2 1 4x5 16 12 1 8x2 1 4x5 16 12 1 8x2 1 4x5 16 12 1 8x2 1 4x5 16 Rear 14 1 8x3x3 8 14 1 8x3x3 8 14 1 8x3x3 8 15x3x3 8 15x4x3 8 Brake Size Increased Capacity Front Same as Standard 12 1 8x2 1 4x5 16 12 1 8x2 1 4x5 16 12 1 8x2 1 4x5 16 12 1 8x2 1 4x5 16 12 1 8x2 1 4x5 16 Rear ee 15x4x3 8 15x4x3 8 15x4x3 8 15x5x3 8 Number of Shoes Front 1 4 2 2 2 2 ee RENE O 2 Double 2 2 2 Front do CENA AO LO M S RS dp Double Double Double Double Double Double 1 1 4 Wheel Cylinder Size Standard 1 1 8 1 1 8 1 1 8 2 2 gt 9 gt gt M e 4 Oe Front 1 1 4 Reni i ss BY Wheel Cylinder Size Increased Capacity Front Same as Standard 1 1 8 1 1 8 1 1 8 1 1 4 1 1 4 Rear ws ST TO tae l 1 3 8 1 3 8 1 1 2 1 1 2 Number of Wheel Cylinders Standard 4422s f 1 2 2 2 2 2 Number of Wheel Cylinders Increased Capacity Front Same as Standard 2 2 2 2 2 Rear o QUEE SENE Master Cylinder Size Bore and Stroke 1 1 4x1 7 16 1 1 4x1 7 16 1 1 4x1 7 16 1 1 4x1 7 16 1 1 2x1 7 16 1 1 2x1 7 16 2 seere Barrel Standard or Optional Standard Standard Standard Standard Standard Model No Bendix s S mae 575279
116. nut If this fails to correct the leakage replace the connectors hose or both Replacement Hose assemblies are easily replaceable by removing the detachable connectors and installing a new piece of hose 1 Remove connector nuts and pull hose out of connector body Donated by John 4 Susan Hansen For Personal Use Only BRAKES L LINE MOTOR TRUCK SERVICE MANUAL Section C Page 16 2 Do not attempt to remove used sleeve from hose 3 Cut a piece of new hose to required length being sure that cut is made at right angles to outside wall of hose and that end of hose is smooth 4 Blow out hose with an air line to re move all cuttings SLEEVE NUT A 9365 Fig 19 5 Placeconnectornutand sleeve on hose Fig 19 being sure that barbs on inside of Sleeve point toward end of hose that is being connected CONNECTOR BODY PROTECTOR P GASKET i a COVERING x A 9363 Fig 20 6 Place new gasket over end of guide in connector body so that side with removable protector covering is next to hose Remove protector covering from gasket Fig 20 BLUNT HOSE CONNECTOR GASKET NOSED GUIDE BODY SCREWDRIVER A 9364 FI g 7 Push gasket into bottom of recess in connector body Fig 21 NUT SLEEVE HOSE GUIDE BODY Fig 22 8 Put end of hose in connector body making sure that end of hose is against gasket at bottom of the recess Fig 22 9 Move sleeve if necess
117. o boot G The combination type master cylinder is also known as a compensating type Its primary compensating function is to maintain a constant volume of fluid in the system at all times re gardless of expansion heat or contraction cold The secondary compensating function is the replacement of additional fluid into the system to counterbalance 1055 due to gravity seepage The return to off position of piston B and cup D is much faster in displaced volume than the return of the fluid through fitting J into the master cylinder A momentary vacuum is created in the cylinder barrel and additional fluid is drawn into the system through the drilled holes in piston B and past the lip of cup D The operating fluid returns more slowly from the wheelcylinders and lines back into the master cylinder barrel excess is by passed by port C into the reservoir Thus we have a cylinder full of fluid for the next brake application 22 Z2zzzz ZZ G I l A 22934 Fig Typical Combination Type Master Cyl inder Donated by John amp Susan Hansen For Personal Use Only BRAKES HYDRAULIC Section Page 2 L LINE MOTOR TRUCK SERVICE MANUAL Check Valve A double check valve is used in all master cylinders of the compensating type It is held in the closed end of the master cylinder barrel by the piston cup return spring The valve performs two functions It acts as
118. o check for leakage through the body by coating the outside of the cut out cock with soapsuds With brakes applied and cut out cock open hose line connected check for leakage through the body by coating the outside of the cut out cock with soapsuds 3 Leakage in excess of a 3 inch soap bubble in 3 seconds in either of these tests is not permissible 4 Leakageis caused by a dirty or scored key body Leakage due to dirt is corrected by cleaning parts and applying a light coating of cup grease to the key Leakage due to a scored key or body cannot be repaired and the cut out cock must be replaced RESERVOIRS 1 Reservoirs are tested against a 200 pound pressure and treated on the inside with a rust preventive WV 2 The purpose of reservoirs is to provide a place to store compressed air so that there willbeanample supply available for immediate useinbrakeoperation They also provide stor age for sufficient compressed air to permit several brake applications after the engine has stopped Another function of a reservoir is to provide place where the air heated during compression may cool and cause the oil and water vapors to condense Testing 1 LEAKAGE TESTS With the air brake system charged coat the outside of the reser voir with soapsuds to check for leakage If any leakage is found replace the reservoir 2 INSPECTION Inspect inside and out side surfaces for damage or corrosion
119. or Personal Use Only BRAKES L LINE MOTOR TRUCK SERVICE MANUAL Section C Page 10 ADJUSTING SCREW M 7 EXHAUST PORT 2 BALL VALVE gt a H 1 A 9348 Fig 10 Sectional View Of Safety Valve Testing Pressure Setting Tests 1 Connect a test gage known to accu rate into the airbrake system so as to register reservoirpressure simple way to do this is to connect the air gage to the emergency line at the rear of the tractor truck and open the emergency line cut out cock With the motor running temporarily stop governor operation by turning the air supply valve on the dash panel to its air supply position and permit the air pressure in the air brake system to rise until the test gage registers 150 pounds When the test gage reaches 150 pounds the safety valve must release or blow off If the safety valve does not release stop the engine imme diately and adjust the pressure setting of the safety valve Do not permit air pressure in the air brake system to build up higher than 150 pounds otherwise the compressor may become damaged 2 To adjust the pressure setting of the safety valve loosen the lock nut and turn the adjusting screw Turning the adjusting screw counterclockwise lowers the pressure setting Turning the screw clockwise raises the pres sure setting Turn the adjusting screw as re quired until the safety valve releases at 150 pounds pressure registe
120. ounting screws 30 small Cylinders easily lift off II WHEEL CYLINDER DISASSEMBLY l Pull boot 20 from wheel cylinder Piston 19 should come with boot Pull boot from piston 2 Piston cup 18 cup filler 17 and spring 16 may be pulled from cylinder Assembly Adjustment cam and shoe guide studs 2 are equipped with friction springs 4 They should easily turn with 8 wrench but should not be loose If frozen lubricate with kerosene or penetrating oil and work free Note C The two wheel cylinders mounted on one brake are identical HOW EVER CYLINDERS FOR LEFT OR RIGHT HAND BRAKES HAVE OP POSITE CASTINGS 15 Note D Clean mating surfaces of cylinders and backing plate before assembly to insure proper alignment Note E When replacing shoe retracting springs 13 place spring end with long hook in heel of shoe and then with brake spring pliers stretch spring to se cure short hook end in toe of opposite shoe Use new springs if there is evidence of spring fatigue rust set springs etc Note F For best results new shoe and lining assemblies 7 should have linings 9 of correct thickness ground not buffed to correct radius concentric with the brake drum Ifthis is not Note G done readjustment may be required after linings are worn in Do not lubricate brake mechanism except as noted in Note H Step By Step Procedure Assembly I
121. oved always dismantle adjusting mechanism and clean dirt dust and grease from the parts and supports Care should be taken to distinguish the adjusting Note C screws as those of the left or right brake The left brake adjusting screws have a left hand thread and the right brake screws have a right hand thread Neither can be assembled to the op posite brake Step By Step Procedure Disassembly Before beginning the following steps on the FR 2S and FR 2SD remove the dust shield attaching bolts and lift off the dust shields II TO REMOVE SHOE ASSEMBLIES Remove brake shoe retracting springs Refer to Note A Pry off shoe guide spring C clip and lift washer off of shoe guide stud Shoes will slide off easily The anchor pins should easily pull out of the supports TO REMOVE WHEEL CYLINDERS WITHOUT DISTRUBING SHOES Remove brake shoe retracting springs Refer to Note A Remove connecting tube fitting bolts from wheel cylinder Remove wheel cylinder bolts Spread shoes away from cylinder until push rods are cleared Lift out cylinder and cover TO REMOVE ADJUSTING MECHANISM Remove shoes from brake Rotate adjusting screw backing off adjust ment to thread it free of star wheel or worm gear Push adjusting screw out of support On FR 2 type lift star wheel and lock spring from slot On 25 and FR 2SD types pry worm retainer snap ring from support and remove thrust washer worm and
122. r Fig 1 The combination type master cylinder consists of barrel and tank casting double check valve L piston cup return spring I piston cup D piston B piston stop P boot G and connecting link A The fluid reservoir or supply tank is cast in tegral over the master cylinder barrel A com bination filler and breather plug N permits atmospheric pressure on the reserve fluid at all times Depression of the pedal causes piston B and cup D to move forward in the cylinder barrel A very small forward movement of cup D closes PRINTED IN UNITED STATES OF AMERICA compensating port C and the pressure stroke commences Actual pressure is not built up until the fluid displaced has caused all shoes to go into con tact with their drums Additional pressure on the pedal produces hydraulic pressure within ihe brake system Removal of operator s foot from the brake pedal after each brake application permits the brake pedal and push rod A to return independently to their off position The return of piston B and cup D is accom plished by the piston return spring 1 The piston for this type of unit is designed to carry primary cup D and a secondary cup E The construction of the piston is such that reserve fluid from the tank passes through vent R ina recessed area Thus we have fluid on both sides of the primary cup The secondary cup is merely seal to prevent loss of reserve fluid int
123. r A to adjust second shoe Repeat steps 3 and 4 Bleeding The Hydraulic Brake System Vehicle brake systems using the self centering hi tork foundation brake are bled in similar manner to other hydraulic systems METHOD A Bleed wheel cylinders in the following order 1 Cylinder lowest to road Cylinder highest from road METHOD B If brake is mounted so that both cylinder bleeder valves are not at the highest point of their re spective cylinder bores it may be necessary to surge bleed the system 1 Bleed brakes at all wheels in regular man ner using Method A 2 At each wheel cylinder in turn open bleeder valve and then kick brake pedal down sharply several times Close bleeder valve This action creates turbulance in each cylinder forcing out any remaining trapped air SERVICE SPECIFICATIONS LINING LENGTH MEASURED INSIDE ARC BOTH LININGS 12 1 8 Drum Diameter 1289 12 7 8 13 Drum Diameter 1279 13 23 32 15 Drum Diameter 1279 15 15 16 LINING WIDTH 12 1 8 Drum Diameter 2 1 4 13 Drum Diameter eee o 2 1 4 15 Drum Diameter ee eee 6 0 9 2 1 4 LINING 55 STANDARD LINING 12 1 8 13 15 Drum Diameters 5 A6 LINING RIVET STANDARD NUMBER 12 1 8 13 Drum Diameters 9 7 5 15 Drum Diameter 9 7 6 WRENCH SIZE Adjustment cam and shoe guide stud 2 he
124. r pressure from the reservoir would escape through the exhaust port of the other brake valve whose exhaust valve would be open When the double check valve is used and one of the brake valves is moved to the applied position the double check valve blocks off the line leading to the other brake valve in this manner preventing any loss of air pressure through the open ex haust valve of the brake valve not being oper ated GASKET iB 2 T i SHUTTLE A 9358 OUTLET Fig 7 Sectional View Of Double Check Valve Testing With the brake system fully charged and both brake valves in released position move one of the brake valves to applied position and check with soapsuds for leakage at the exhaust port of the brake valve not being operated Re peat test with the other brake valve Leakage in excess of a 3 inch soap bubble in 3 seconds is not permissible If excessive leakage is found the defective double check valve must be replaced RELAY VALVE Description The relay valve Fig 8 speeds up the ap plication and release of the rear wheel brakes It is controlled by the brake valve and keeps the air pressure in the rear brake chambers the same as the pressure being delivered by the brake valve 11 reacts to even slight changes L LINE MOTOR TRUCK SERVICE MANUAL in pressure and raises lowers or completely exhausts the air pressure in the rear brake chambers as the brake valve rai
125. r proper clearances Excessive shoe clearance will cause loss of pedal reserve travel Insuf ficient shoe clearance may cause dragging brakes Donated by John amp Susan Hansen For Personal Use Only INTERNATIONAL ff Donated by John amp Susan Hansen For Personal Use Only L LINE MOTOR TRUCK SERVICE MANUAL BRAKES AIR Section C Page 1 AIR BRAKES For Description and Operation see Shop Talk No 24 AIR BRAKE EQUIPMENT Air brake equipment on trucks and truck tractors provides a means of controlling the brakes through the medium of compressed air Air brake equipment consists of a group of devices Some maintaina supply of compressed air some direct and control the flow of the compressed air and others transform the en ergy of compressed air into the mechanical force and motion necessary to apply the brakes Different types and sizes of devices are used on different types of vehicles to meet oper ating requirements but they are all fundamen tally the same Following are the devices comprising atypical truck or truck tractor air brake system with a brief description of the function of each device Compressor The compressor supplies the compressed air to operate the brakes Governor governor controls the compression of air by the compressor Although the compres sor runs continuously when the engine is run ning the governor acting in conjunction with the unloading mechanism
126. rake system reaches a point between 66 and 54 pounds Donated by John amp Susan Hansen For Personal Use Only BRAKES AIR Section C Page 12 L LINE MOTOR TRUCK SERVICE MANUAL N EY SPRING t DIAPHRAGM YS FROM RESERVOIR CONTACT POINTS g A 9353 i Lud Fig 4 Sectional View Of Low Pressure Indi cator Leakage Test With the air brake system fully charged coat the outside of the low pressure indicator with soapsuds to check forleakage No leakage is permissible Leakageat the lower diaphragm screwcan sometimes be corrected by removing the electrical connection and carefully tighten ing the terminal screw nut Leakage through the small vent hole in the cover signifies a leaking diaphragm and the low pressure indi cator must be replaced STOP LIGHT SWITCH Description The stop light switch 15 mounted on the left hand frame side rail Stop light switches are electro pneumatic switches which close the stop light electrical circuit when the brakes are applied see Fig 15 Testing 1 With all air pressure exhausted from the air brake system move the brake valve to applied position and start the engine Observe at what pressure registered by the dash gage the stop lights light Stop lights must light be fore the dash gage registers 10 pounds pres sure Withbrakes applied coat the stop light switch with soapsuds to check for lea
127. re at the correct ends of the cylinder and the push rod socket in each piston faces outward Refer to Note D Slip boots over ends of cylinder so that the boot edges fit squarely into the grooves on the casting Place push rods into assembled boots and cylinder TO REPLACE ADJUSTING MECHANISM Do not lubricate parts Refer to Note E On the FR 2S and FR 2SD types place worm in sleeve and slip them into hole in adjusting support Open side of sleeve must face worm wheel slot Insert thrust washer and snap ring be sure snap ring fit firmly into groove in wall of worm hole Omit this step with the FR 2 type brake Hold star wheel FR 2 or worm wheel FR 2S FR 2SD in slot in adjusting support and slide adjusting screw into the outer end of the support so that the keys machined on the inner circumference of the wheel en gage into the keyways on the adjusting screw Be certain to use the correct ad justing screws for the left and right brakes Refer to Note C Rotate worm or star wheel to thread ad justing screw into support TO REPLACE WHEEL CYLINDER WITHOUT DISTRUBING SHOES Be sure backing plate or spider is clean so that cylinder and cover will fit properly when mounted Spread shoes as far apart as possible Place cylinder and cover in proper position on the backing plate or spider and fasten securely with wheel cylinder bolts and lock washers Screw in connecting tube fitting bolt Refer to Note B
128. rear secondary shoe clearance tighten the anchor locknut with a 16 wrench and then recheck anchor and adjusting end clearances NOTE If anchor pin nut is loosened too much the anchor pin may shift when tighten ing the locknut To adjust rear parking brake cables expand shoes at both rear brakes until tight against brake drums With parking brake lever applied approximately 1 from fully released position pull cables by hand to remove all slack Adjust cables as required at yoke ends so that clevis pins can be inserted Insert clevis pins and new cotter pins At both rear brakes back off star wheel adjusting screw 12 to 14 notches To check rear brakes for balance pull parking brake lever back until rear wheels can just be turned by hand Check rear wheels for even brake drag If drag is uneven loosen the tight brake to provide even drag Replace adjusting hole covers Donated by John amp Susan Hansen For Personal Use Only Donated by John amp Susan Hansen For Personal Use Only L LINE MOTOR TRUCK SERVICE MANUAL HYDRAULIC BRAKES BRAKE SHOE ADJUSTMENTS AND SERVICING LM 120 LM 121 LM 122 12 x 2 Backing Adjusting plate hole cover A 22940 Fig Front External View Anchor pin Bleeder valve me mer Adjusting hole cover Backing plate A 22926 Fig 3 Rear External View PRINTED IN UNITED STATES OF AMERICA BR
129. rease and dirt off of backing plate and sand down shoe ledges if rusted or ridged Apply a thin coating of suitable lubricant comparable to Lubriplate to all shoe ledges Thoroughly clean star wheel adjusting screws pivot nuts hold down pins springs and cups of front brakes and clean star wheel adjusting screws locksprings hold down nuts and washers of rear brakes Apply a small amount of suitable lubricant comparable to Lubriplate to threaded end of the adjusting screws and to points of contact of the shoe webs with the shoe links and anchor buttons PERFORM THE FOLLOWING OPER ATIONS AT EACH FRONT WHEEL SEE FIGS 1 AND 2 When installing new brake shoes lay the shoes out in pairs according to their position on the truck The upper secondary shoe is the shoe with the longer lining Thread the star wheel adjusting screw into the pivot nut to the limit of the threads and assemble star wheel adjusting screw and spring to the adjustment end of the shoes NOTE Always assemble pivot nut on the right hand shoe as viewed from the adjusting screw end of the shoes regardless of whether the brake shoes are for left or right side of truck Assemble shoe links to wheel cylinders and guide forked end of shoe links over anchor end of shoe webs Attach brake shoes to backing plate with shoe hold down pins springs and cups PRINTED IN UNITED STATES OF AMERICA 15 NOTE 17 18 19 20 NOTE
130. red by the test gage Then tighten the lock nut to hold the adjusting screw at the proper setting Reduce air pres sure in the air brake system to normal of AMIDA approximately 100 pounds applying and releasing the brakes Leakage Tests With the air brake system fully charged to approximately 100 pounds coat the safety valve all over with soapsuds to check for leak age Leakage of a l inch soap bubble in 5 seconds is not permissible Slight leakage may sometimes be corrected by lightly tapping the end of the release pin If this fails to correct the leakage replace the safety valve SLACK ADJUSTER Description One slack adjuster is used at each brake chamber Slack adjusters consist of a worm and gear enclosed in a body which also serves as an adjustable lever Fig 11 They provide a quick and easy means of adjusting the brakes to compensate for brake lining wear During brake operation tbe entire slack adjuster ro tates bodily with the brake camshaft During brake adjustment the worm moves the gear so as to change the position of the lever arm in relation to the brake camshaft Slack Spring loaded adjuster sleeve type adjusting screw lock Adjusting screw A 22838 Fig 11 Sectional View Of Slack Adjuster INTERNATIONAL Donated by John amp Susan Hansen For Personal Use Only L LINE MOTOR TRUCK SERVICE MANUAL BRAKES AIR Section G
131. res that shoes are resting against the anchor pin Donated by John amp Susan Hansen For Personal Use Only foie 1 MENTS Section H L LINE MOTOR TRUCK SERVICE MANUAL VN 4 27 Revolve brake drum so that feeler gauge hole is about 1 1 2 from the anchor end of the rear secondary shoe lining There should be a slightly heavier drag on the feeler gauge at this point If the clearance at the anchor end of the shoe is greater than the clearance at the adjustment end by 003 or more it will be necessary to adjust the anchor pin 28 To adjust anchor pin loosen locknut 1 4 to 1 2 turn and tap anchor pin either up or down to provide the correct anchor pin position After positioning the anchor pin to provide the correct rear secondary shoe clearance tighten the anchor pin lock nut with a 16 wrench and then recheck anchor and adjusting end clearances NOTE If anchor pin is loosened too much the anchor pin may shift when tightening the locknut 29 Replace adjusting hole covers Donated by John amp Susan Hansen For Personal Use Only BRAKES L LINE MOTOR TRUCK SERVICE MANUAL DS Page l HYDRAULIC BRAKES BRAKE SHOE ADJUSTMENTS AND SERVICING L 151 L 152 L 153 LM 152 d e Brake shoe web Brake sboe hold down pee Wheel cylinder P S J Au A b Brake shoe hold down bracket Adjusting P Anchor Retracting spring 5 5 hole cover pi
132. ruck FRONT BRAKES ONLY Guide forked end of shoe links over anchor end of shoe web and attach shoes to backing plates by means of shoe hold down pins springs and cups REAR BRAKES ONLY Place parking brake lever strut spring against shoulder at front primary shoe end of strut Guide forked end of strut and shoe links over anchor end of Shoe webs Attach shoes to backing plate by means of shoe hold down pins springs and cups REAR BRAKES ONLY Attach cable to parking brake lever by sliding yoke at brake end of cable over hook end of packing brake lever Attach retracting springs to shoes and anchor pins If springs show signs of having been overstressed they should be replaced PRINTED IN UNITED STATES OF AMERICA 21 Install brake drums For lubrication and NOTE 224 23 24 25 26 21 28 adjustment of front wheel bearings see Wheel Section DO NOT LOOSEN ANCHOR PINS UNLESS INSPECTION OF LINING TO DRUM CLEARANCE INDICATES A NEED FOR REPOSITIONING OF ANCHORS Insert a 015 feeler gauge between the lining and drum of the rear secondary shoe about 1 1 2 from the star wheel ad justing screw end of the shoe and expand shoe by turning star wheel adjusting screw until feeler gauge cannot be withdrawn Then turn star wheel adjusting screw in opposite direction until there is but a light drag on the feeler gauge Withdraw feeler gauge NOTE Expanding Shoes until feeler gauge cannot be wit
133. s METHOD A Bleed wheel cylinders in the following order 1 Cylinder lowest to road 2 Cylinder highest from road METHOD B If brake is mounted so that both cylinders are almost in a vertical plane it may be necessary to surge bleed the system 1 Bleed brakes at all wheels in regular manner using Method A 2 At each wheel cylinder in turn open bleeder valve and then kick brake pedal down sharply several times Close bleeder valve This action creates turbulence in each cylinder forcing out any remaining trapped air SERVICE SPECIFICATIONS LINING LENGTH measured inside arc Both Linings 16 Drum Diameter 16 1 8 LINING WIDTH 16 Drum Diameter 4 5 LINING THICKNESS Std Lining I6 Drum 3 8 TORQUE WRENCH READING SHOE ANCHOR BLOCK LOCKNUT 16 Drum Diameter 3 4 16 Thrd 175 219 Ib ft INTERNATIONAL Donated by John amp Susan Hansen For Personal Use Only BRAKES ADJUSTMENTS Section M L LINE MOTOR TRUCK SERVICE MANUAL Page 1 PARKING BRAKE FOR LM 120 L 130 L 150 LM 150 L 160 LC 160 L 170 LF 170 SERIES TRUCKS Parking Brake Adjustments See Fig 1 Note Perform operations in sequence given l Place parking brake lever in extreme for ward release position NOTE Brake cam lever must rest squarely on the upper brake band bracket If necessary readjust linkage 2 The
134. s back through conduits Wipe off excessive grease from backing plate Apply a thin coating of suitable lubricant comparable to Lubriplate to shoe ledges and on rear brakes apply to the parking brake lever fulcrum and strut contact points Thoroughly clean star wheel adjusting screws pivot nuts hold down pins springs and cups Apply a small amount of suitable lubricant comparable to Lubriplate to the threaded end of the adjusting screw and to contact points on the shoe webs When installing new shoes lay the shoes out in pairs according to their position on the truck The rear secondary shoe is the shoe with longer lining REAR BRAKES ONLY On rear shoes at tach parking brake levers to backing plate side of shoe web Place spring washer on parking brake lever pin and insert pin through lever and shoe from the backing plate side Assemble lockwasher and nut Adjust nut so that parking brake lever is under spring tension but free of bind REAR BRAKES ONLY Attach parking brake lever strut to parking brake lever from side opposite backing plate with conical spring flat washer and cotter pin Thread the star wheel adjusting screw into the pivot nut to the limit of the thread and assemble star wheel adjusting screw and adjusting screw spring to the adjustment end of the shoes with pivot nut against the right hand shoe NOTE Always assemble pivot nut on the right hand shoe regardless of position of shoes on the t
135. s operating a brake valve capable of giving finely graduated brake con trol and making full use of this feature An air braked vehicle should not be moved unless the air gage shows at least 60 pounds air pressure in the air brake system because the brakes are not fully effective at lower pressures While operating the vehicle the driver should periodically observe the air pressure registered by the dash gage to be sure itis being maintained properly If the air pressure drops to a low point or if the warn ing buzzer or light signifies the pressure is low the vehicle should be stopped and the trouble corrected The best stop results when the brake ap plication is as hardat firstas the speed condi tion of the road and passenger comfort permits and then graduated off as the speed decreases As the stop is completed there should be only sufficient air pressure in the brake chambers to hold the vehicle stationary The brakes must never be applied lightly at firstand the braking pressure increased as the speed decreases as this will result in a very rough stop The brake pedal should not be fanned as this merely wastes compressed air and has no bearing on correct braking results The brake pedal should not be fully de pressed except in cases of emergency as this causes full braking force to be delivered to the wheels and this should not be necessary in ordinary service Normally the engine is used to assist the brakes by
136. same manner 27 Install brake drums 28 To adjust front shoe insert screwdriver or special brake adjusting tool through slot in backing plate upper front and expand front brake shoe to the point where the wheel can just be turned by hand 29 Back off star wheel adjusting screw 6 notches 30 To adjust rear shoe insert screwdriver or special brake adjusting tool through slot in backing plate lower rear and expand rear brake shoe to the point where the wheel can just be turned by hand Back off star wheel adjusting screw 6 notches 31 32 Replace adjusting hole covers Donated by John amp Susan Hansen For Personal Use Only L LINE MOIOR IRUCK SERVICE MANUAL BRAKES ADJUSTMENTS Section J Page 1 HYDRAULIC BRAKES BRAKE SHOE ADJUSTMENTS AND SERVICING L 160 L 161 L 162 L 163 L 164 L 165 LC 160 LC 161 LC 162 L 170 L 171 L 172 L 173 L 174 L 175 LF 170 LF 171 LF 172 L 180 L 181 L 182 L 183 L 184 L 185 LC 180 LC 181 LC 182 L 190 L 191 L 192 L 193 L 194 L 195 LF 190 LF 191 LF 192 LC 190 LC 191 LC 192 L 200 L 201 L 202 L 204 L 205 LC 200 LC 201 LC 202 Brake hose Backing plate connection Brake shoe cam lt adjustment A Bleeder valve Brake shoe cam adjustment B Bleeder valve A 23197 Fig Front Brake External View Type PRINTEO IN UNITED STATES OF AMERICA FRONT BRAKE 12 1 8 x 2 1 4 TYPE
137. sen For Personal Use Only L LINE MOIOR TRUCK SERVICE MANUAL 20 els Cos 23 24 29 0 Li BRAKES ADJUSTMENTS Section D Page 3 Install brake drums For lubrication and adjustment of front wheel bearings see Wheel Section NOTE DO NOT LOOSEN ANCHOR PINS UNLESS INSPECTION OF LINING TO DRUM CLEARANCE INDICATES A NEED FOR REPOSITIONING OF ANCHORS Insert a 015 feeler gauge between the lining and drum of the rear secondary shoe about 1 1 2 from the star wheel ad justing screw end of the shoe and expand shoe by turning star wheel adjusting screw until feeler gauge cannot be withdrawn Then turn star wheel adjusting screw in opposite direction until there is but a light drag on the feeler gauge Withdraw feeler gauge NOTE Expanding shoes until feeler gauge cannot be with drawn insures that shoes are resting against the anchor pin Revolve brake drum so that feeler gauge hole is about 1 1 2 from the anchor end of the rear secondary shoe lining There shouldbe a slightly heavier drag on the feeler gauge at this point If the clearance at the anchor end of the shoe is greater than the clear ance at the adjustment end by 003 or more it will be necessary to adjust the anchor pin To adjust anchor pin loosen locknut 1 4 to 1 2 of a turn and tap anchor pin either up or down to provide the correct anchor pin position After positioning the anchor pin to provide the correct
138. ses lowers or completely exhausts air pressure from it BRAKE VALVE PORT BY PASS PORT NEA 4 BRAKE CHAMBER EXHAUST PORT PORT SUPPLY VALVE p GASKET RESERVOIR PORT ans o gt Fig 8 Sectional View Of Relay Valve CAP NUT A 9357 Testing for Serviceability Operating Tests 1 With the air brake system charged apply brakes and check to be sure the rear wheel brakes controlled by the relay valve ap ply promptly 4 Release brakes and check to be sure air pressure is exhausted from the exhaust port of the relay valve promptly Leakage Tests l With brakes released coat the exhaust port with soapsuds to determine leakage 2 With brakes fully applied coat the ex haust port with soapsuds to determine leakage 3 Leakage in excess of a one inch soap bubble one second is not permissible in either of these tests If excessive leakage is found the relay valve must be repaired or replaced GOVERNOR TYPE O 1 Description The purpose of the compressor governor is to automatically control the air pressure being maintained in the reservoirs the air brake system by the compressor between the maximum pressure desired 100 105 lbs and the minimum pressure required for safe brake operation 80 85 lbs To understand this func tion of the governor it should be remembered that while the compressor may run continuous ly actual
139. still be greater than 90 In other words the slack adjuster should not go over center when the brakes are applied Fig 13 The position of the push rod yoke on the push rod should be adjusted if necessary until these conditions prevail Maintenance Ihe worm gear and worm should be kept welllubricated This can be done by removing the plug and filling the cavity with a good grade of chassis lubricant every 1 000 miles LOW PRESSURE INDICATOR Description The low air pressure indicator Fig 14 is a safety device designed to give an automatic warning whenever the air pressure in the air brake system is below approximately 60 pounds Operating as an air controlled switch of an electrical circuit the low pressure indicator automatically sounds a buzzer when the air pressure drops too low some vehicles a light is used to indicate low pressure in place of the buzzer Testing l Drain air brake system turn on igni tion key and start engine The low pressure indicator buzzer must sound until the air pres sure in the air brake system reaches a point between 54 and 66 pounds when the buzzer must stop sounding 2 Continue to build up air pressure in theairbrake system until the pressure reaches at least 75 pounds stop engine and reduce the air pressure in the air brake system by mak ing brake applications Check to see at what pressure the buzzer again sounds buzzer must sound when the pressure in the air b
140. ston cup 3 Shoe amp lining assembly Spring 4 Shoe amp insert assembly Piston assembly short 5 Lining Piston short 6 Rivet lining Cup piston 7 Screw adjusting shoe Ring segment back up piston cup 8 Washer end thrust adjusting worm Boot 9 Sleeve adjusting worm Cap boot retainer 10 Worm adjusting shoe Washer spring cylinder mounting 11 Ring snap worm retainer Link connecting piston to shoe 12 Wheel driven adjusting worm Cover wheel cylinder 13 Spring brake shoe retracting Cover wheel cylinder 14 Bolt shoe guide Valve bleeder cylinder 15 Sleeve shoe guide bolt Tube assembly connector wheel 16 Washer plain shoe guide bolt cylinder 17 Lockwasher shoe guide bolt Gasket fitting 18 Nut shoe guide bolt Fitting inlet fluid connector tube 19 Nut lock shoe anchor block Gasket bolt 20 Block assembly shoe anchor Bolt fitting inlet brake pipe to 2 Wheel cylinder assembly cylinder amp tube 22 Body wheel cylinder Bolt fitting inlet connector tube 23 Piston assembly long to cylinder 24 Piston long Donated by John amp Susan Hansen For Personal Use Only L LINE MOTOR TRUCK SERVICE MANUAL BRAKES ADJUSTMENTS Section L Page 3 Brake lining xis Brake adjusting wrench A 23450 Fig 3 Brake Adjustment Type FR Brake MAINTENANCE AND ADJUSTMENT WAGNER SELF CENTERING TYPE FR BRAKES Figs 1 and 2 The Wagner self centering Hi
141. sure Indicator The low pressure indicator is often pro vided to warn the driver by sounding a buzzer or by lighting warning light if for any reason the air pressure in the air brake system falls below a safe operating point Stop Light Switch The airoperated stoplight switch provides a simple means ofcontrolling the stop lights of the vehicle Air Horn On some vehicles the air horn is included to provide an effective warning signal Alcohol Evaporator On some vehicles the alcohol evaporator is included to prevent moisture freezing in the air brake system OPERATION OF THE AIR BRAKE EQUIPMENT Charging The reservoirsare charged with air by the compressor The reservoir air has access to the inlet valve chamber of the brake valve and the inlet valve is then held closed by the tension of its spring and air pressure Service Application When it is desired toapply the brakes foot pressure is applied to the brake pedal which action is carried through the brake rod pulling up on the lever of the brake valve This com presses the spring deflects the diaphragm downward andthrough the medium of the rock arm closes the exhaust valve and opens the inlet valve Air is thereby admitted from the reservoir to the brake valve thence out the two side outlets to the front and rear brake cham bers The power thus exerted against the brake chamber diaphragms or pistons forces the push rods out rotating the camshafts to
142. t The air cleaner should be inspected every 1000 miles If air passages are restricted re move the air cleaner dismantle and thoroughly clean all parts in cleaning solvent and allow to drip dry Then saturate the air cleaning element with a light oil reassemble and install ER ex on vehicle A 22878 NOTE Where the air inlet line is connected Fig 7 Hydrovac Air Inlet Filter to the engine air filter servicing the air filter as outlined in the Fuel System Maintenance Section will suffice CAUTION hose connections must be secure and leak proof Vacuum Line Oil Bath Air Cleaner Fig 8 On trucks having a separate air cleaner for the vacuum line this unit is located on the engine side of cowl at upper right hand corner The qud Check valve Outlet to engine vacuum line air cleaner prevents any dirt or foreign matter being drawn into intake manifold when the brakes are applied In normal operation service the cleaner every 5000 miles by re moving oil reservoir cleaning thoroughly in a suitable cleaning solution or kerosene and re filling with clean engine oil to indicated level on side of reservoir Fig 8 Use same grade of oil as used in engine crankcase CAUTION Be sure that reservoir seats per fectly against gasket and that clamp is correctly installed after completing service operation Should a leak occur the engine performance and hydrovac operation will be seriously affected
143. tandard ETON 3244 Z w 3 fo la la Un v Uu 2 2 Double O mT lt m pe d Qu M Un N c ty d t amp 1 1 2 b I UJ n d m w H 4 TVAaNVIA JOANS AONYL SANIT I d b i d fa i Number of Wheel Cylinders Increased Capacity Front Same as Standard Master Cylinder Size Bore and Stroke 1 3 4x2 1 2 1 3 4x2 1 2 TD Barrel Barrel 7 GW Standard or Optional Standard Standard Model No ommo 0 DEPIBS 4 wo ON EUR ii e dd V sess d ERIS Single or Tanden Piston Tandem Tandem These hydrovacs contain residual pressure check valve and must used with a master cylinder that does not have residual pressure check valve 2 4 1545 z A m gt o rr Donated by John amp Susan Hansen For Personal Use Only 41 1 2x8 es 2 Cyl 9 Length and Diameter 41 1 2x8 Air Compressor Type Westinghouse 2 Cyl Capacity in Cu Ft 1 1 4 2 Cyl 7 1 4 Water AIR BRAKE SPECIFICATIONS vg tj x Fu PN P Bi LC 200 P og
144. tandard Standard Model No Bendix 374229 375218 375278 314230 375218 374230 Series e lt e G v 9 lt v wp ugn Cylinder Diameter 9 1 2 9 1 2 9 1 2 9 1 2 9 1 2 9 1 2 Single or Tandem Piston Single Guided Single Guided Single Guided Tandem These hydrovacs contain a residual pressure check valve and must be used with a master cylinder that does not have a residual pressure check valve p 229 lt WALSAS x gt Z gt r TVANVW 39IAW3S AONUL YOLOW ANITI wvOIH3HY dO SILVLS GALINN NI O3ANIHd Donated by John amp Susan Hansen For Personal Use Only HYDRAULIC BRAKE SPECIFICATIONS Continued LF 160 LF 221 LF 222 L 220 L 225 TRUCK MODEL Brake Hydraulic Brake Size Standard Front 16 1 2 3 1 2 5 8 Rear vua 38 16x4x3 8 Brake Size Increased Capacity Front Same as Standard L 230 L 231 LF 239 LF 231 Hydraulic 16 1 2x3 1 2x5 8 Front S dw wt Q a a e p l Type of Anchor ipee wa Double Front xxu S s Re N 1 1 2 Wheel Cylinder Size Increased Capacity Front Same as Standard Number of Wheel Cylinders S
145. ted and brakes applied coat the hose couplings all over with soapsuds to check for leakage There must be no leakage Leakage is usually caused by worn damaged or improperly installed gaskets correct leakage install new gaskets 3 Remove old gasket by prying out with screwdriver Before attempting to installa new gasket be sure the groove in the coupling in which the gasket fits is thoroughly cleaned Otherwise it will be impossible to install a new gasket properly Fig 23 PRINTED IN UNITED STATES OF AMERICA Donated by John amp Susan Hansen For Personal Use Only L LINE MOIOR TRUCK SERVICE MANUAL BRAKES AIR Section C Page 17 4 To installa new gasket partially col lapse it with the fingers Fig 23 and enter one side of the gasket lange in the groove in the coupling BLUNT NOSED SCREWDRIVER GASKET A 9362 Fig 24 5 Then use a blunt nosed screwdriver or similar instrument to push the gasket into place Fig 24 When properly installed the exposed face of the gasket will be flat not twisted or bulged at any point TUBING Operating Tests If any evidence is found that a tubing line is restricted remove and blow air through it inbothdirections tobe sure the passage through the tubing is notobstructed in any way Inspect tubing for partial restrictions such as may be caused by dents or kinks Damaged tubing must be replaced Leakage Tests With the air brake
146. ted be tween the shoes at each toe and heel Upon brake application the wheel cylinder pistons transmit pressure to the toes of the shoes forcing the shoe linings into contact with the brake drum If the vehicle is moving for ward the drag of the drum against the shoe lining produces self energization which tends to help rotate the shoes outwardly about their anchor points This action multiplies the forces PRINTED IN UNITED STATES OF AMERICA Donated by John amp Susan Hansen For Personal Use Only BRAKES ADJUSTMENTS L LINE MOTOR TRUCK SERVICE MANUAL Section J Page 3 exerted against the drum and produces additional braking effect Both shoes are forward acting primary shoes self energizing in the forward direction of drum rotation If the vehicle is moving backward the drag of the drum on the linings is in the opposite direction and produces de energization which tends to move the shoe heels away from their anchor blocks Piston forces at the shoe toes are large enough to overcome this action but the shoes tend to rotate inwardly about their anchor points and attempt to leave the drum Both shoes are reverse acting since neither is self energized in the reverse direction of drum rotation Cylinder anchor block sides are aligned on the axle radius As the shoes roll upon their anchor blocks to contact the drum the heels may also slide radially upon the anchor block surface The shoes thus automaticall
147. ther damage Install new lining if old lining shows excessive wear or is saturated with grease or brake fluid 6 Inspect brake drums for scores run out or cracks If scores are not too deep or run out does not exceed 010 drums may be machined If drums are badly scored or cracked they should be replaced 7 Inspect wheel cylinders for signs of fluid leakage or deteriorated rubber dust boots If brake fluid is leaking out of wheel cylin ders replace or recondition wheel cylinders 8 Clean grease and dirt off backing plate and sand down shoe ledges if rusted or ridged 9 10 11 12 13 14 15 16 17 18 19 Disconnect parking brake cables to rear brakes at intermediate lever end Wipe off dirt and grease from exposed portion of cables and pull cables through con duits as far as possible from the brake end and wipe off old grease Apply a generous coating of cable lubricant to cables and slide cables back through con duits Wipe off excessive grease from backing plate Apply a thin coating of suitable lubricant comparable to Lubriplate to shoe ledges and on rear brakes applyto the parking brake lever fulcrum and strut contact points Thoroughly clean star wheel adjusting Screws pivot nuts hold down pins springs and cups Apply small amount of suitable lubricant comparable to Lubriplate to the threaded end of the adjusting screw and to contact points on the shoe webs
148. ting mechanism Z s s se s e s e e s e 10 Replacement of brake shoes Tr SCAN PONO EOS 9 N 10 Replacement of wheel cylinders TTD TT Tn 10 Service ww xw S P S k Q s 12 Wheel cylinder assembly TP Q 9 Wheel cylinder disassembly 404 44 s s s sr e s sz s s s e e O9 sc a oy s s s s e e e 9 SECTION L 184 L 190 L 191 L3192 L 193 L 195 LC 190 LC 191 LC 192 LF 210 LF 211 LF 220 LF 221 LF 222 REAR BRAKES 16 4 TYPE FR L 194 L 200 L 201 L 202 L 205 LC 200 LC 201 LC 202 REAR BRAKES 16 5 TYPE FR Bleeding the hydraulic brake system v w w w a w 0 s noct 6 Brake adjustm enlLl 44 xo wo SU Sw MED E W E TETTETETT Se oe 5 Brake component parts Rue 2 Removal of brake 5 Sb z S TUTTI 3 Removal of shoe adjusting mechanism lt lt wa w a s w w a 4 Removal of wheel cylinders W S TIT TET 3 4 Continued PRINTED IN UNITED STATES OF AMERICA Donated by John amp Susan Hansen For Personal Use Only BRAKE SYSTEM L LINE MOTOR TRUCK SERVICE MANUAL BRAKE SHOE ADJUSTMENTS AND SERVICING CONTINUED SECTION L Con d Page Replacement of shoe adjusting mechanism
149. to be unseated by its spring which opens brake cham ber line to atmosphere and allows air to ex haust from the brake chambers If the brake valve lever is moved all the way back to normal position and left there foot entirely removed from brake pedal the brakes will entirely release but if moved only part way back foot pressure eased the brakes will only partially release i e the exhaust valve will remain open until the brake chamber pres sure has reduced to such an amount as will no longer hold the diaphragm up whereupon the regulating spring will move the diaphragm with rocker arm downward again and close the exhaust valve The brake chamber line to the rear wheels 15 released only up tothe quick release valve or relay valve This allows the diaphragm to un seat uncovering the exhaustportthrough which the rear brake chambers are then exhausted OPERATING INSTRUCTIONS Operating the brakes of an air braked ve hicle differs very little from operating the brakes of a passenger car Because operation of the brake pedal requires very little physical effort proper control of the brakes is easily accomplished l h The distance the brake pedal is depressed determines the amount of air pressure deliv ered to the brake chambers and the brake chamber pressure determines the braking force Thus the driver may definitely control the brakes of the vehicle by keeping in mind the fact that he i
150. um valve Diaphragm return spring Atmospheric valve Atmosphere inlet from ME yr 2 8jr cleaner Piston return E qr Control valve E valve spring I body O Bleeder valve XA t o Outlet to wheel d i Hydraulic piston i Cylinder shell m T y o g ers support stud SSS cmn ar Slave cylinder B By pass valve PA Toe by pass valve Push rod Inlet from master cylinder Vacuum piston gt P Push rod seals Lubrication plug End plate Vacuum inlet from vacuum source Cylinder shell inlet drawn out of position 23201 Fig 2 Sectional View of Third Series C Series Single 6 3 u Diameter Piston Hydrovac No 374000 PRINTED IN UNITED STATES OF AMERICA Donated by John amp Susan Hansen For Personal Use Only BRAKES POWER LINE MOTOR TRUCK SERVICE MANUAL Page 2 UNIV Atmosphere control line Bleeder valve Trailer brake Cylinder shell connection plug 1 Control valve t lt guide tube Atmosphere inlet int y 4 from air cleaner 4 d ad Lit 7 t Lock He 3 _ Bleeder pu End plate 5 Outlet wheel _ s AN LT cylinders Slave cylinder B MN Clamp bol ES amp bolt Inlet from master cylinder Stabilizing support stud holes inlet from vacuum source
151. utside of the drain cock with soap suds Leakage in excess of a 3 inch soap bub ble in 3 seconds is not permissible 2 Leakage is caused by dirty or scored key or body Leakage due to dirt is corrected by cleaning parts and applying a thin coating of cup grease on the key Leakage due to a scored key or body cannot be repaired and the drain cock must be replaced HOSE HOSE ASSEMBLIES AND HOSE CONNECTORS Description Hose and hose fittings provide a means of making flexible air connections between points on avehicle which normally change their position in relation to each other also of mak ing flexible connections between two vehicles All hose assemblies include detachable type hose connectors with spring guards Hose assemblies used to connect the air brake sys tem to another vehicle are fitted with hose couplings The two hose lines or hose cou plings at the rear of the tractor truck are marked by tags identifying them as SERVICE or EMERGENCY Testing 1 If any evidence is found indicating that a hose line is restricted remove and blow air through it in both directions to be sure the passage through the hose is not obstructed in any way 2 With the brakes applied to be sure that the hose line being tested is under pressure coat the outside of the hose and connections with soapsuds to check for leakage No leakage is permissible Leakage at the connectors is sometimes corrected by tightening the con nector
152. w piston to uncover compensating port allowing fluid to escape into tank Donated by John amp Susan Hansen For Personal Use Only BRAKES HYDRAULIC L LINE MOTOR TRUCK SERVICE MANUAL Page 3 Bleeder wrench Brake Us Z i 231854 Fig Brake Pedal Free Travel Z A Bleeding The Lines Also see HydrovacSection Any air inside the hydraulic system must A 22936 removed Whenever a line has been discon nected at master cylinder the entire system must be bled at all wheels until all air is completely expelled When a line has been disconnected at any wheel cylinder this cylinder together with the cylinder on the opposite wheel must be bled Air in the system will cause a springy rubbery action of the brake pedal Should a sufficient quantity be introduced into the system the brake pedal will go to toeboard under normal pressure Fill master cylinder supply reservoir with genuine Lockheed or any high grade automotive type brake fluid and see that it is kept at least half full during entire bleeding operation Use pressure type brake bleeder where avail able Attach bleeder tube to bleeder valve by pushing tube over the end of bleeder valve Allow tube to hang in a clean container such as pint glass jar Unscrew bleeder valve 3 4 turn and depress brake pedal by hand using half strokes allowing pedal to return slowly Pumping brake pedal forces fluid out
153. worm wheel from slot TO DISASSEMBLE WHEEL CYLINDERS Take push rods out of boot assemblies and slip boots off ends of cylinders Remove pistons and spring by pushing either piston through and out of cylinder Cups are removed by slipping cup protector segments off and working cups over the end of the pistons PRINTED UNITED STATES OF AMERICA Donated by John amp Susan Hansen For Personal Use Only L LINE MOTOR TRUCK SERVICE MANUAL BRAKES ADJUSTMENTS Section K Page 9 Assembly Note D Each brake utilizes two wheel cylin Note E Note F Note G ders which are identical The piston actuating the toe of each shoe has provision for a longer stroke than the other piston This is to compensate for adjustments made on the shoe which move the shoe toe away from the wheel cylinder Thus the long stroke piston is built longer than the short stroke piston and is also identified by a circular groove machined at the bottom of the push rod socket The cylinder casting is constructed with the bleeder valve and connecting tube inlets offset toward the short stroke end of the cylinder PISTONS MUST BE ASSEMBLED IN THE PROPER ORDER WITHIN THE CYLINDER Otherwise fluid will enter the cylinder chamber improperly and may be forced out past the short stroke piston Do not lubricate shoe adjustment mechanism or other parts of the brake Lubrication will cause dirt and dust to collect and solidify in the adjust ment m
154. y self center in relation to the drum The self energization factor causes this brake to be approximately three times as effective during forward operation as it is during verse operation therefore its use is generally confined to the front axle of vehicles in con junction with a rear axle brake of a type viding effective stopping ability in reverse as well as forward motion Disassembly Note A The first disassembly operations is always removal of brake shoe re tracting springs 13 With brake Spring pliers pull one hooked end of spring free of shoe web Note B If wheel cylinder connector tubes 21 are removed mark wheel cylinder ports to which tubes are attached to avoid error in re assembly Dif ficulty will be encountered in bleeding operation if tubes are assembled in wrong location Step By Step Procedure Disassembly I REMOVAL OF SHOE ASSEMBLIES 1 Remove both brake shoe retracting springs 13 Refer to Note 2 Remove each shoe hold down C washer 12 and washer 11 Shoes easily lift off II REMOVAL OF WHEEL CLYINDERS 1 Remove brake shoe assemblies 7 Remove connector tubes 21 and wheel cylinder fittings 24 Refer to Note B Donated by John amp Susan Hansen For Personal Use Only BRAKES ADJUSTMENTS Section J Page 4 L LINE MOTOR TRUCK SERVICE MANUAL 3 Remove each cylinder anchor screw 27 large and washer 29 4 Remove cylinder m
155. y 20 000 miles which ever occurs first The lubrication service should be performed with the hydrovac mounted on the vehicle with the engine stopped and brakes released Single piston hydrovacs have one pipe plug in the cylinder shell Figures 2 and 4 remove pipe plug and fill cylinder with vacuum cylinder oil to the level of the bottom of the hole Replace pipe plug Tandem piston hydrovacs have two pipe plugs one in the end plate below control valve and the other in the center plate between the vacuum cylinders Fig 5 Remove pipe plugs and fill cylinder with vacuum cylinder oil to the level of the bottom of the holes Re place pipe plugs NOTE The quantities of oil required are automatically controlled by the position of pipe plugs They are located so as to es tablish the proper oil level Donated by John 4 Susan Hansen For Personal Use Only BRAKES L LINE MOTOR TRUCK SERVICE MANUAL PYPROVAC POWER Page 5 HYDROVAC OIL CAPACITIES ARE AS FOLLOWS APPROXIMATE OIL CAPACITY END CHAMBER CENTER CHAMBER 6 3 4 Diam qo NS Single Piston 5 9 1 2 Diam Hair filter element HYDROVAC SIZE 2 ounces 9 1 2 Diam landem Piston 2 ounces Hydrovac Air Inlet Filter Fig 7 On all hydrovac installations a filter is pro vided to cleanthe air eniering the power chamber whenever the brakes are applied This filter is located on the inside of cab below driver s sea

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