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Fuel System - Hansen Web Design

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1. Governor ad we A 22183 Fig 5 Throttle body NG Leathe 4 WA k Gasket E Washer Governor bod f NG ZA Ai aes d mc A 22179 Mark flange and plates A 22168 Fig 52 Fig 55 PRINTED IN UNITED STATES OF AMERICA FUEL SYSTEM Section D Page 16 L LINE MOTOR TRUCK SERVICE MANUAL The four throttle plate screws have been upset and must be filed flat before removing to avoid breakage or stripping of threads in shaft Re move four throttle plate screws Fig 56 Remove the throttle plates Remove the throttle stop screw and spring Fig 57 Fig 58 Remove the retainer spring holding the throttle shaft and bearing as sembly in place Remove the throttle shaft and bear ing assembly by tapping threaded end of shaft lightly with a soft hammer Note Do not attempt to remove the bearing on end of shaft as this bear ing is pressed and staked in place Fig 59 Insert a 9 32 brass rod through shaft hole at throttle lever end and remove throttle shaft bearing by tapping lightly on the brass rod Fig 60 The foregoing completes removal of all parts from the throttle body parts should be kept to gether in a group ready for cleaning and in spection before reassembly Throttle plates A 22178 Throttle stop screw ME Fig 57 MV A 22197 Retainer spring Fig 58 Bearing Throttle shaft Clutch A 22196
2. Fig 36 Fig 39 A INTERNATIONAL N NA Donated by John 4 Susan Hansen For Personal Use Only L LINE MOTOR TRUCK SERVICE MANUAL FUEL SYSTEM Section D Page 13 Turn casting over and remove the third throttle body to main body as sembly screw Access to this screw is by means of a hole in carburetor mounting flange face hj E 00 As nN t Separate the main body from the throttle body assembly and remove gasket Retain all parts removed from main body assembly as a group for cleaning and inspection Fig 43 Fig 44 Remove seal and wire from governor body cover plate screws Remove cover plate screws and lock washers Note Plug screw located in cover plate This screw serves to plug blind hole in governor housing and has no effect on carburetor opera tion Fig 45 Fig 46 Remove governor body cover plate and gasket Economizer valve 7 A 22188 lt Main body a j Throttle body 7 Throttle body to main body assembly screws A 22187 Fig K PRINTED IN UNITED STATES OF AMERICA b Cer SUM yu ii Throttle body pa ET Fig 42 z L at A Gasket NA 7 Throttle body Fig 43 A 22170 Donated by John 4 Susan Hansen For Personal Use Only FUEL SYSTEM Sea c L LINE MOTOR TRUCK SERVICE MANUAL Fig 47 Remove the governor spring with the f
3. M A N INTERNATIONAL N y V b W S y IN Donated by John amp Susan Hansen For Personal Use Only N L LINE MOTOR TRUCK SERVICE MANUAL FUEL SYSTEM GROUP INDEX SPECIFICATIONS Carburetor Carter bha Gol IG WG FUR E 3 GB E E E ee eae Carburetor Holley o lt 44 4455046 3 3 dod v8 9 ah C E9090 38 CP e A Ud PUCWPUINUG wu X wok AG AG WA AGA PEER ORR EEE CHER OE V EORUM EUR SECTION A FUEL SYSTEM AND FUEL PUMPS GENERAL Auxiliary electric pump installation o AC e CR OEC UR Truck storage preparation of fuel system Pu ded Vapor lock 52 x 4 x44x maawa gt FUEL PUMPS Desetiption and Operation s w 840 0 3 ww o woe X 9 Xo oor E OU a Tial CHECK 4 4 a4 5 ok edm xw X koX o3 3 5 4 x3 AX OX 4 How to diagnose fuel pump trouble 64624466 o ww ox R OX COE d oem ee A Installation of fuel pump assembly lt 6 aa oes Ke 0 ee we oe ew lt Loacating fuel putup trouble sss ssr erein KR UE NA AAA SECTION B CARBURETOR CARTER MODEL YF DESCTP Oi a Maa 4 8 3 9 9 9 2 9 ee ea Oe A BN Tr LDi5assembly 23 444 Wo rrise Tm Pee Eo ET SEE Le ew tat aeons ee be Oe es BE eee KER RE Sa AA aasa AA a SECTION C CARBURETOR CARTER MODEL BBR 1 Carburetor O CLA a 343 3 4 4 9 23 939 344 42 4 ES 3 94
4. Choke wire bracket Retainer screws Diaphram v housing Main body be assembly A 22221 mu A 22547 Fig 10 Fig 10 The carburetor is in reality an as sembly of four major subrassemblies These assemblies are identified above and should be disassembled and kept together in their respective groups Disassembly Disassembly of the carburetor is as follows atra we A 22548 Fig 11 Loosen screw in choke lever clamp Gasket and remove lever Fig 12 Remove two choke wire bracket re a tain Main body aining screws and lockwashers and remove the choke wire bracket Fig 13 Remove six air horn assembly screws and lockwashers PRINTEO IN UNITED STATES OF AMERICA Donated by John amp Susan Hansen For Personal Use Only AM A NNV V FUEL SYSTEM zar D L LINE MOTOR TRUCK SERVICE MANUAL age Fig 14 Separate air horn from main body assembly and remove gasket Be careful not to damage float Fig l5 Remove float shaft and float Fig 16 Remove fuel valve needle Note The fuel inlet valve seat and gasket are serviced as an assembly and should be used in matched sets as supplied Fig 17 Remove fuel valve needle seat and gasket using a large screw driver that fits the slot properly or SE 1190 14 wrench Fig 18 Remove economizer piston and stem A 22154 assembly Use special wrench to fit piston retainer Fig 19 In removing the choke plate no
5. gardless of whether or not a vacuum by pass is used around the governor Illustrations Figs 1 to 8 show the location of the various parts and will aidin correctly PRINTED IN UNITED STATES OF AMERICA identifying the various assemblies when dis mantling the YF model carburetor for complete reconditioning as outlined in the following step by step instructions Air horn ba and fuel bowl cover Choke shaft Choke As lever N W ES i R Fuel bowl cover ff attaching screws a yo E pr Fast idle connector MANE rod and spring NG ud Body flange jattaching screw Throttle stop screw S e sx d OS Idle adjusting screw Throttle JE lever A 22880 Fig Carter Model YF Carburetor Low speed or idling jet fy Pump disc retainer ring E R rot KA 3 L WS Accelerating 50r RES 2 2h discharge nozzle of rrie k bee LAN A 22904 Fig 2 FUEL SYSTEM Section B Page 2 L LINE MOTOR TRUCK SERVICE MANUAL a Pump intake A a N ll Accelerating pump assembly A 22903 Metering 7 bs C rod arm SIE E retainer E Upper pump spring Metering rod H as 250 H Diaphragm Bas housing attaching _ screws strainer Pump lifter gt A 22902 Float pin A 22901 l Fig 5 Throttle lever retainer gff Flange assem
6. needle to raise level or toward needle to lower float level Bend vertical lip of float only Use float gauge SE 1639 10 and check level as shown Setting is 5 64 plus 1 64 below top surface of carburetor body casting and without the body gasket Idle adjusting screw pu M to 114 turns open C Bel 7127 Fig 3 Idle adjustment is 3 to i turns open For richer mixture turn the idle screw out orifice tube and plug assembly air bleed idle port idle mixture adjusting screw throttle valve carburetor bore and economizer HIGH SPEED CIRCUIT The intermediate and high speed circuit consists of the step up jet step up piston and rod assembly main metering jet main vent tube diffuser holes and air passage PUMP CIRCUIT The acceleration circuit consists of the Donated by John 4 Susan Hansen For Personal Use Only FUEL SYSTEM Section C Page 2 accelerating pump spring pump plunger and rod assembly pump leather inlet valve outlet valve pump jet air bleed and pump Jet The accelerating pump is provided with an adjustable stroke setting Set the accelerator link in the inner hole in the throttle shaft lever for summer operation For winter setting use the outer hole CHOKE CIRCUIT This circuit is used only in starting and warming a motor its purpose being to supply a rich mixture temporarily It consists of a choke shaft and lever assembly a choke valve choke breather valve and spring and
7. A EP ab P c CROKE a sas ars irausi aranak QU wo 9o 3 V 1e ae AAA IDeSCTIDLI N sss KG 99 Wow MOA EC CON 66 ss ee ee COREE Aaa EC I o Dg aca wu ume d s HiIBhespeed 617 4 se do we Soe des we oe ee SS T Ge AG Lowespesd CITCUIL rimas add PITT POND CITCU 393 X36 RA Ge RUE x AEREA SECTION D CARBURETOR HOLLEY MODEL 852 FFG Acceleralin PUMP xc wo AID AAA EOE OE eL eS DESCTIPUION ara errada idie duel SySDeTDL s asni ditia X o9 uw Yon dehors cR d d a a NO d ex o Bdain Idel SYSTEM 099 o 9d ox ARA A E EU Rss dd Power mixture supply Tm sw KA ADJUSTMENTS AND SERVICE HINTS Accelerating DUI nos doe e e T lo EES HO KB Se e s TETE Altitude OPETAUON o4 3 4 93 9 93 40 WA OHH ECONOMY complalnis 4 4d awa a SHH 99 4 Ea 9 oy GG EU Po wow s Failure to 1dle properly sra 4 xo ox KN DORR AA AAA Finaladjusime i s ww sonoro XXX NM AED XE XX HES 3 9 9 KAG C SOR Float level xa koe e RO ess ROSSO CUAL COR ND UR ADU A EBA BA de E AX JEDE om High speed complaints rea seses oo 9 o t o c n lt ldling Speed wa sacos a a o CELESTE RSE Ow 9 AO Main fuel IE AA A coe PRINTED IN UNITED STATES OF AMERICA FUEL SYSTEM Index Page
8. C Per Min 025 54 C C Per Min 025 Fuel Inlet Needle Seat 098 Accelerator Pump Plunger Stroke Adjustable Adjustable Power Jet Economizer Valve No 25R 80A 43 No 25R 80A 58 Flanges no 9939 5 8 AY 1 1 4 SAE Dual 1 1 4 SAE Dual Idle Adjusting Screws 3 4 to 1 1 4 Turn Open 3 4 to 1 1 4 Turn Open Main Well Bleed 025 031 Aspirating Hole wa naa 992 35 043 067 Accelerating Jet uoo WR 4 033 33 Idle Air Bleed u 0465 0465 Well TubeS oooo 3 32 O D 4 Holes 028 3 32 O D 6 Holes 040 Idle Progression Hole 56 DR 0465 56 DR 0465 Idle Adjusting Hole 56 DR 0465 56 DR 0465 Accelerator Pump Spring 040 Wire 040 Wire Secondary Venturi 3 8 I D 3 8 I D Bowl Cover Plate Vent Holes ka 2 18 DR 1695 2 18 DR 1695 Only last two digits of number appear on power jet 23ed Continued ze OO ADIANSS NINAL YOLOW ANITY suorjeorjroadg NALSAS TANA Donated by John 4 Susan Hansen For Personal Use Only SPECIFICATIONS COVERING HOLLEY CARBURETOR MODEL 885 FFG USED ON RD 406 AND RD 450 ENGINES FUEL SYSTEM SPECIFICATIONS Continued ENGINE MODELS RD 406 RD 450 GOVERNOR HOLLEY 885 FFG 885 FFG Governor Spring Color Marking Yellow Plain Governor Spring Position in H
9. Fig 59 Bearing A 22185 Fig 60 Ni NA Donated by John 4 Susan Hansen For Personal Use Only FUEL SYSTEM AMA L LINE MOTOR TRUCK SERVICE MANUAL 2 IN age Fig 61 Remove the washer and leather seal from governor body Fig 62 Remove the governor housing by pass jets The assembly of governor by pass passage jets is shown above The outside diameters of the A jet and B jet are not identical hence it is impossible to assemble them incorrectly Fig 63 Remove the seal and wire from the three governor diaphragm cover retaining mounting screws Fig 64 Remove the eight governor diaphragm cover retaining screws Fig 65 Remove diaphragm cover Use a soft hammer and tap lightly around the edge of the cover until cover breaks loose DO NOT PRY COVER OFF Remove the diaphragm and rod as sembly If diaphragm sticks to the body flange carefully work it loose with the fingers A 22195 Washer A 22194 Fig 64 CN Diaphragm Fig 61 Governor by pass passage jets M Diaphragm cover A 22193 j Fig 65 Pi NOTE The foregoing instructions com pletely strip the governor keep all the compo A 22453 l E nent parts togetherfor cleaning and inspection Fig 62 in preparation for reassembly PRINTED IN UNITED STATES OF AMERICA Donated by John 4 Susan Hansen For Personal Use Only FUEL SYSTEM Section D Page 18 L LINE MOTOR TRUCK SERVICE MAN
10. Hansen For Personal Use Only z A ri x 1 gt SIE o FUEL SYSTEM SPECIFICATIONS M 33 2 3 Y dO SALVLS GALINA NI 31 ENGINE MODELS RD 406 RD 450 CARBURETOR HOLLEY Model number AA 1G 852FFG 852FFG Float level 1 1 4 1 1 4 1 1 4 2 x po obra 1 1 16 1 3 16 Main jets 059 061 Idle tubes 0 88 C C per min 64 C C per min Bleeder plug or button in nozzle bar 175 234 234 Fuel inlet needle seat 098 098 098 Accelerator pump plunger SITORE eadra a sasaaa adjustable adjustable adjustable Power jet economizer VIVE 4 sce xe eo No 25R 67A No 25R 72A 49 No 25R 72A 66 Flange dre 1 1 4 SAE 1 1 4 SAE dual 1 1 4 SAE dual Idle adjusting screw GOVERNOR HOLLEY Governor spring color marking ados 3 s Governor spring position in housing lt ae amp xu Governor by pass jet hole A Governor by pass jet hole B Maximum no load speed Governor rotor valve and housing assembly IH partnumber 3 4 to 1 turn open 54 784 R91 3 4 to 1 turn open 54 784 R91 Only last two digits of number appear on power jet 3 4 to 1 turn open 54 784 R91 28e4 TIWANVW 3OIAWJS NINAL YOLOW 3NTTI suor3eortjioads WALSAS TANA Donated by John amp Susan Hansen For Personal Use Only Donated by John amp Susan Hansen For P
11. caps from over the valves and test for freedom of action The filtering screen if in a gummed con dition should be replaced and the sediment bowl cleaned If there is doubt as to the condition of the carburetor it is suggested that a one quart mixture of 50 50 CP acetone and gasoline be burned through the carburetor at fast idle from a closed container attached direct to the car buretor not through the fuel pump because of the detrimental effect of acetone on fuel pump diaphragms This willserve to remove alarge amount of the gum providing that it has not be come hard and varnishlike If the results are not satisfactory the carburetor must be removed and all jets and carburetor valves replaced FUEL PUMPS DESCRIPTION The fuel pump is installed on the engine between the fuel tank and the carburetor The suction side of the pump is connected to the fuel tank and the discharge side to the carburetor by tubing designed to carry the fuel The pur pose of the pump is to suck fuel from the supply tank and push it into the carburetor float bowl as it is required by the engine OPERATION The pumping operation is accomplished through a rockerarm on the pump contacting an eccentric on the engine camshaft The link is hinged to the rockerarm so that it can be moved down but cannot be raised by the rockerarm The only function ofthe rocker arm spring is to make the rockerarm follow the cam The link and diaphragm are moved by
12. estes ws bea esasa Cd Z5 Operating pressure 3500 engine 3500 engine 3500 engine Ll r p m r Dp m ee aa gt Z E gt suot e2rjyr2oadg INWISAS TANA 9883 Donated by John amp Susan Hansen For Personal Use Only FUEL SYSTEM SPECIFICATIONS ENGINE MODELS SD 240 CARBURETOR CARTER Model number ha YF 735 S YS 136 S Float level 25 64 1 64 7 16 1 64 Flange Lena dra 1 1 4 SAE 1 1 4 SAE Venturi 1 5 16 1 5 16 Main jet ow o xs 104 1015 A A Baw we 9A 0276 0292 Accelerating jet 025 025 Main air bleed 034 034 Fuel valve seat 076 081 Metering rod No 75 693 No 75 688 Idle adjustment 3 4 to 1 3 4 turns open 3 4 to 1 3 4 turns open Used with governor yes yes FUEL SYSTEM SPECIFICATIONS ENGINE MODEL CARBURETOR CARTER Model number Float level MAINJET soso aa ws late DUDE s s perrera Accelerating pump jet Step up JED i 2 2 Fuel valve seat Idle adjustment Used with governor BD 269 BBR1 617SA 5 64 t 1 64 1 1 4 SAE 1 5 16 298 C C 031 0315 0374 086 1 2 to 1 1 2 turns open yes 7 23d suomneorji2odg IN X LSAS TANA 3 Z m lt O i O A 4 A E C Un T A us C 53 gt L E gt m Donated by John amp Susan
13. fuel line or loose carburetor assembly screws 6 Improper carburetor adjustment NOTE If none of these is the cause of flooding or poor gasoline mileage then the pump needs overhauling FINAL CHECK After overhauling a simple check of the suctionand pressure should be made before in stalling the pump on the engine This can be done by holding the fingers over the inlet and outlet openings of the pump and manipulating the rockerarm by hand The pump may then be reinstalled on the engine and tested See in stallation instructions below It should prime itself that is fill the filter bowl in about 30 seconds with the starter button depressed If it fails to provide sufficient pressure the dia phragm has beenincorrectly installed prevent ing thefull stroke of the push rod or the springs do not have sufficient tension and it will be necessary to disassemble the pump to reinstall the diaphragm correctly or to replace the link age springs if this has not been done INSTALLATION OF FUEL PUMP Use a new gasket between fuel pump mount ing flange and pad on crankcase and tighten cap screws securely Connect fuel lines first making sure that there is no dirt on the fittings which might be drawn into the system If carburetor has not been removed there will usually be sufficient fuel in it to run the engine long enough to fill the fuel pump filter bowl If there is an air leak between filter bowl and gasket the pum
14. l NNN Ww Ww W W Po PA PM Ka N N Ka Kad ee WIRD WN WA Donated by John amp Susan Hansen For Personal Use Only FUEL SYSTEM Index L LINE MOTOR TRUCK SERVICE MANUAL Page 2 FUEL SYSTEM GROUP Cont d INDEX SECTION D CARBURETOR HOLLEY MODEL 852 FFG Cont d OVERHAUL CARBURETOR AND GOVERNOR M INA VW Cleaning CERA paa GG rh GT TATE i 18 DISASSCObIY serora BAKA o ABA EE CEES RH eas Poe OR CER e e d 1 to 18 Governor adjustment 45 e4 5 9 9 3 oe dw ha T PANA Inspection and assembly rers AK GNG AAA OS EDS OHS 18 to 22 SECTION E AIR CLEANERS DESCLIDUON 2 ee ee ES EERE Ge ER ORE ES EE ORD EO Ee SEE OS SES GS l DETVICINP ua KGABI E 9o 4d AAA AAA l 1 O1 CAPACITY ss did oe IAM Xo POR AAA AAA ARA 9 w 9 lt Donated by John amp Susan Hansen For Personal Use Only mee SPECIFICATIONS COVERING HOLLEY CARBURETOR MODEL 1904 FS USED ON SD 220 240 AND BD 269 ENGINES TT S LO 303 sodud peaueuro ddng 61 HONVIA 71T SLI YDIIYAWY JO SILVILS QILINN NI GalNidd FUEL SYSTEM SPECIFICATIONS CARBURETOR HOLLEY MODEL NUMBER 5 4 4955 1904FS 1904FS 1904FS Float Level EE MC 145 MC 145 MC 145 ganito CE R uas enny 1 5 16 1 5 16 1 5 16 Z K 2 69 Std Alt 70 Std Alt 70 Std Alt 7 73 High Alt 73 High Alt 73 High Alt Power Jet 052 55 DR 04
15. or otherwise damaged Replace the assembly if the rod is bent or twisted Donated by John 4 Susan Hansen For Personal Use Only L LINE MOTOR TRUCK SERVICE MANUAL FUEL SYSTEM Section D Page 21 10 11 12 Note Sealing surfaces of diaphragm housing and cover must be clean and free from nicks or burrs Install diaphragm assembly to housing with the bent end of the rod parallel with the throttle shaft and pointing away from the throttle body See Fig 48 Line up the holes and place diaphragm cover in position Note Be sure that suction connector tube Fig 65 in cover fits into suction channel in the body properly Assemble cover to body with eight screws and lockwashers Thread all screws in until both flange surfaces nearly come together Then with the thumb or fingers pull the diaphragm rod as far back toward the throttle shaft as possible hold it there and tighten every other cover assembly screw tight Then release the rod and tighten the remaining screws Note When inserting the cover screws ob serve the three screws that are drilled for the seal wire Space drilled screws as shown in Fig 63 Install the seal wire and seal GOVERNOR LEVER Replace the lever if the pin is loose or if rod is worn Start lever onto throttle shaft and work end of diaphragm rod into hole in lever Press lever into position and assemble to shaft with hex nut and lockwasher Be sure that nut is started correctl
16. rough polish with a small piece of No 320 wet or dry abrasive paper Place float in position in hinge bracket Be sure float balancer spring is in position FLOAT LEVER SHAFT Replace shaft if bent or shows excessive wear at bearing ends Assemble shaft and float to bracket There should be at least 005 clearance on each side of float lever and assembly bracket If end play is insufficient remove the float and spread the bracket FLOAT LEVEL SETTING Hold air horn assembly at eye level float side up and gauge float Gauge must just slide over top of float when float is in closed position If float is too high press it down gently with the fingers and regauge If float is too low remove it and insert a narrow screw driver between the float bracket and lip Twist the screw driver enough to raise the lip In stall float and regauge See Float Level Adjustment ECONOMIZER PISTON AND STEM AS SEMBLY Examine assembly closely Replace if piston is worn stem is bent or spring is damaged Install economizer piston and stem assembly After completing installation of economizer piston and stem assembly place casting to one side until ready to assemble to main body Main Body l CASTING All gasket surfaces must be smooth and clean If any sealing surface is damaged to the extent that a perfect seal is impossible the casting must be replaced INTERNATIONAL Fig 66 Pump the operator rod and seal In
17. spring MIM Donated by John amp Susan Hansen For Personal Use Only L LINE MOTOR TRUCK SERVICE MANUAL FUEL SYSTEM Section C Page l CARTER MODEL BBR 1 CARBURETOR FOR DETAILED DISASSEMBLY INSTRUCTIONS SEE SHOP TALK NO 35 Fast idle rod F Pump link Idle screw Flange assembly A 17083 Description The Carter Model BBR 1 617SA carbur etor Fig 1 is a downdraft carburetor divided into five circuits which consist of the following FLOAT CIRCUIT The float circuit controls the height of the gasoline level in the bowl Fig 2 A gasoline level too high or too low may cause trouble in other circuits and make complaints hard to trace The float circuit consists of a needle valve seat and gasket float float bowl float bowl cover float lever pin retainer float pin gasket and vent hole LOW SPEED CIRCUIT The idle or low speed circuit controls the supply of gasoline to the engine during idle and no load up to a speed of approximately 15 to 20 m p h and it partially controls the supply of fuel for no load or light loads at higher speeds Fig 3 The low speed circuit consists of the idle PRINTED IN UNITED STATES OF AMERICA Float setting gauge y Float 77 Fig 2 Before adjusting float level be sure float lever pin is firmly seated and that the float pin retainer is in position Reset float level by bending lip of float lever away from
18. the accelerating pump to stick Gum deposits in the fuel pump will cause the fuel filter to become clogged or the check valves to stick IMPORTANT Itis well to emphasize the possibilities that can develop because of gum film in carburetor jets A thin film of gum assume 002 thick is transparent and would escape casual inspection but this thickness of film represents a 004 reducation in orifice size and shouldone orall jets beaffected there would be alean mixture ratio that would be det rimental to the engine as well as performance for it would contribute to sticking and burning of valves because of gum accumulation on the stems The condition would also be a contrib uting cause of premature spark plug failures Gum is not soluble in gasoline therefore any reduction in the capacity of the jets willbe per petuated almost indefinitely The best known means of preventing gum formation in trucks that are to be placed in storage or allowed to stand idle for a period of two or more weeks is to thoroughly condition the fuel system as follows l Completely drain the fuel tank 2 Run engine until all fuel is consumed in carburetor 3 Remove plug from carburetor under main jet assembly to complete drain ing 4 Empty sediment bowl at fuel pump The possible affected parts in the fuel pump are the check valves and the filtering screen or filtering element To determine the condition of the check valves remove the
19. throttle valve seated press down on upper end of diaphragm shaft Metering rod should be seated in cast ing and metering rod arm Fig 3 flat against pump lifter link A If metering rod does not seat in body casting check by pressing downward on metering rod or seats before the metering rod arm makes flat contact with pump lifter link raise or lower by bending lip B on metering rod arm Adjust float level as shown in Fig 3 Width of gauge is 25 64 for YF 735S car buretor and 7 16 for YF 7368 carburetor A tolerance of plus or minus 1 64 is per missable in each float level setting Install needle seat and gasket assembly needle float and float pin NOTE Stop shoulder on float pin must be on side away from bore of carburetor Set float level to catalog page specifications Measure from machined surface of casting gasket removed Adjust by bending lip which contacts needle L LINE MOTOR TRUCK SERVICE MANUAL 39 40 41 Install air horn gasket and air horn as sembly Install attaching screws and lock washers 7 and choke tube clamp assembly Tighten center screws first Slide choke shaft and lever assembly into place and connect choke lever spring In stall choke valve Center valves by tapping lightly and hold in place with fingers when tightening screws Install fast idle connector rod with offset portion of the rod to top of pin spring to the outside Install fast idle connecting rod
20. tighten all screws tight Be sure throttle lever spring bracket is in stalled in correct position at accelerating pump chamber See Fig 67 Place as sembly to one side being careful not to damage accelerating pump operating rod 21 Note During the disassembly operation the plates and barrels were marked No 1 and No 2 Place No l plate in No l barrel Install the throttle plate with the bevel edge down and facing the countersunk side of shaft Close the plate and using the pre viously scribed lines as a guide center tbe plate in the bore and assemble plate to shaft with new screws Before drawing screws tight be sure the plate is properly centered Repeat same procedure to install the other throttle plate Then check the four as Throttle spring YA sembly screws to be sure they are tight A Upset the threaded ends of the screws with a blunt center punch and a light hammer Be sure to support opposite side of shaft to prevent bending After upsetting screws check the shaft to make sure it oscillates freely If shaft binds or drags tap screw heads lightly with a brass rod until shaft operates freely n Ru ng ber ia lt a e ka Tay thing t 41130 ESI TET iti TIT tit Rest throttle body on bench with threaded end of shaft up N D f NG Governor Body Ag 1 Check all sealing surfaces for cracks nicks or imperfec
21. 14 15 16 LT 18 19 FUEL SYSTEM Section D Page 19 DISCHARGE NOZZLE BARS Replace nozzle bars if damaged in any way All drillings and channels must be free from dirt blow out thoroughly with compressed air Install four new neoprene nozzle bar gaskets in place Note In all cases where nozzle bars have been removed from casting for any reason use new gaskets when reas sembling To install gaskets place a gasket on the blade of a narrow screw driver and put blade at edge of gasket seat Then elevate handle of screwdriver until gasket slides into place Install nozzle bars in place being careful not to dislodge gaskets Note Nozzle bars are marked with the letter R or L meaning right or left on the outer wall of the idle tube housing See Fig 36 Place nozzle bar marked R next to accelerating pump chamber Place nozzle bar clamp in position on op posite side of fuel bowl Insert short clamp screws and star washers through clamp and tighten screws just enough to hold nozzle bars in place IDLE TUBES Replace idle tubes if bent or otherwise damaged blow out idle tubes with compressed air and install in place Fig 34 Idle tubes must be tight on seats Install the remaining nozzle bar clamp first being sure to install the fuel pump dis charge nozzle and gasket Also make sure fuel pump discharge ball check and spring are still in place Tighten both clamps Install new bleede
22. 3 57 DR 0595 53 DR High Speed Bleed 031 68 DR 031 68 DR 028 70 DR Q Main Well Bleed Upper 025 72 DR 025 72 DR Main Well Bleed Lower 025 72 DR 025 72 DR 025 72 DR Idle Well Restriction 032 67 DR E Idle Air Bleed 055 54 DR 0595 53 DR E Idle Transfer Hole 0465 56 DR 0465 56 DR lt Idle Adjusting Screw Accelerator Pump Spring Accelerator Pump Link 33R 207 33R 207 33R 207 Accelerator Jet 0293 69 DR 0293 69 DR 0293 69 DR m Fuel Seat 082 082 082 SE EA Y Used With Governor Yes Yes Yes 0 mg S t 0 Use gauge SE 1772 9 Use gauge SE 1772 9 Adjust Screw to Obtain 350 to 400 R P M Adjust Screw to Obtain 350 to 400 R P M 38R 452 035 Wire 38R 452 Wire Use gauge SE 1772 9 Adjust Screw to Obtain 350 to 400 R P M 38R 452 Wire Donated by John amp Susan Hansen For Personal Use Only a pH SPECIFICATIONS COVERING HOLLEY CARBURETOR MODEL 1904 H USED ON BD 282 ENGINE NG o FUEL SYSTEM SPECIFICATIONS x ENGINE MODELS BD 282 Not RC Trucks S CARBURETOR HOLLEY MODEL NUMBER 1904H Float Level Use Gauge SE 1772 9 MC 145 VentUTI uu 99 ooa re KGG ha WAG 1 3 8 Mam C o spaka oe AG 9 RUE ehe ide
23. 72 Fig 2 plates and a separate main metering system and idle system one for each side NOTE In the following explanations one side is generally referred to unless mentioned otherwise Idle Fuel System The fuel from the carburetor bowl 12 passes through the main metering jet 13 into the idle tube 10 as shown in Fig 2 Air is introduced into the fuel stream by idle air bleed 8 This fuel and air mixture then travels through the idle passage 1 through the chamber around the bleeder plug 16 and to the continuation of passage 1 then discharges at idle transfer hole 2 and idle discharge hole 3 When the engine is set to idle ata speed of approximately 350 r p m the mixture is dis charged out of the lower hole 3 only As the throttle plate 5 is opened and the engine speed and air flow increases the upper idle trans fer hole 2 starts discharging in addition to the lower hole at about 450 r p m The action and timing are such that the discharge from the upper hole reaches a maximum at approximately 750 r p m and then gradually becomes less effective as the main nozzle 15 begins to flow The lower discharge hole 3 is provided with an idle adjusting needle 4 Turning this needle out to the left gives a richer mixture and turn ing in to the right a leaner mixture The idle adjustment should be set with a vacuum gauge for the highest and steadiest vacuum reading or Donated by John 4 Su
24. D STATES OF AMERICA cover raises the level pushing it away from the cover lowers the level NOTE The fuel inlet valve valve seat and gasket are serviced as an assembly and should be used as supplied in factory matched sets When replacing the valve seat be sure to use a screwdriver with a blade wide and heavy enough to fill the slots in the valve seat IDLING SPEED ADJUSTMENT First set the idling speed by adjusting the throttle stop screw Fig 5 The idle mixture is controlled by the idle ad justing screws Fig 5 NOTE These screws regulate fuel flow and are not air bleed needles Turning these screws in or to the right makes the mixture leaner and turning them out or to the left makes the mixture richer Screws should be turned in until they just touch the seat then backed off one full turn Care should be taken not to jam the screws against the seat tight enough to groove the points If this occurs the needles will have to be replaced before a satisfactory adjustment can be made The screws should be adjusted with the fingers to avoid damage When the engine has warmed up turn both idle screws in until the engine starts to slow down then turn both idle screws out until the engine starts to slow down A point half way between these two will be very close to the correct idle mixture After arriving at the correct mixture it may be necessary to reset the throttle stop screw to obtain the correct idle s
25. TEM Ad A Paez L LINE MOTOR IRUCK SERVICE MANUAL 3 Recheck all visible assembly screws make sure all are tight DO NOT DISTURB INITIAL SETTING OF IDLE ADJUSTING NEEDLES AND THROTTLE STOP ADJUSTING SCREW 4 PUMP OPERATING LINK Replace the link if bent twisted or worn Install link over pump operator shaft stud first then start pin end of link into No 2 hole on the throttle lever for normal operation Push link all the way onto stud 5 Install cotter key holding pump link to stud bend open ends of cotter key around stud Note The recommended position for the pump link is in the No 2 hole Placing the use link in the No 3 hole increases the pump stroke and hence increases the accelerating gi fuel charge to maximum Placing the link in A AIR BLEED OUTLET No l hole shortens the pump stroke and de i TO CARBURETOR creases the accelerating fuel charge to i minimum Fig 68 DISTRIBUTOR BRACEKET 6 THROTTLE LEVER SPRING Install spring being sure loops are securely hooked at spring bracket and throttle lever ADJUSTING CARBURETOR FINAL ADJUSTMENT SCREW PLUG All adjustments made during assembly procedures were preliminary Final and accurate adjust ments can only be made after carburetor is mounted on engine ADJUSTING GOVERNOR MODEL 1174 A 8662 Connect tachometer and adjust governor to cut off within the engine no load cut off range see Specifications as follows l Turn off ignition sw
26. UAL Cleaning l The disassembled carburetor should be segregated into the four major groups Clean the castings and parts in each in dividual group Wash castings thoroughly in cleaning solvent and blow out all passages with compressed air CAUTION Do not wash LEATHER parts or governor DIA PHRAGM in cleaning solvent If these parts are dirty wipe them with a soft cloth Wash metal parts in a cleaning solution and rinse them ina solvent solution Dry all parts thoroughly Remove all carbon deposits from throttle body bores and throttle plates CAUTION A wire or drill used to clean metered jets or discharge holes will destroy the accurate calibration and defeat the purpose of the Do not use a wire brush to clean overhaul parts Inspection and Assembly Inspect and assemble castings and parts by groups e NOTE Inspect all parts thoroughly check closely for any possible defect Replace any doubtful parts Never use old gaskets when reassembling ihe carburetor Air Horn and Float Bowl Cover Replace all defective parts and assemble as follows l CASTING Examine for cracks or breaks Be sure sealing surfaces of casting are smooth and clean Float lever bracket must not be twisted or bent Install new choke shaft felt in choke shaft hole counterbore Assemble choke wire clamp bracket to casting with the two mounting screws Mount bracket with the clamp end to the left when holding casting
27. VN V Donated by John amp Susan Hansen For Personal Use Only L LINE MOIOR TRUCK SERVICE MANUAL FUEL SYSTEM Section D Page 3 Taga Air horn less gasket A 22481 Fig 4 Before making any adjustments to the carburetor it is important that the breaker points and spark plugs be properly spaced the ignition timing cor rect and valve tappets set to proper clearance Check all carburetor assembly screws and mani fold flange bolts see that they are thoroughly tightened and that there are no leaks at gaskets FLOAT LEVEL Proper carburetor perfor mance is dependent on maintaining the correct fuel level in the bowl The float level can be set accurately when the air horn is off by gauging the distance between the bottom of the float and the flange surface of the air horn Holding the air horn upside down less gasket and with the float in the closed position measure the distance from the flange surface of the air horn to what would normally be the bottom side of the float not the soldered seam Fig 4 The correct distance that it should measure is 1 11 32 To correct the float setting the float lever arm 11 Fig 2 should be bent up or down to bring the float within the established limits and thus correct the fuel level for best opera tion Pushing the float toward the float chamber EC M Y Idie screws stop screw A 22241 Fig 5 PRINTED IN UNITE
28. a means of controlling the position of the valve It incor porates a fast idle cam connected to the choke shaft by a rod When the choke is closed the throttle valve is forced open slightly by thecam to make starting easier and prevent stalling The choke breather valve allows sufficient air to enter so that the motor will start and not flood even though the choke valve is fully closed Carburetor Overhaul See Shop Talk No 35 for complete instruc tions and details When disassembling the carburetor keep the various groups of circuit parts together so that each group can be inspected and replaced completely before proceeding to the next group Use a sectionalized pan or muffin tin to sepa rate each group of parts Reassembly of the carburetor is practi cally the reverse of disassembly A complete set of servicing tools is provided to facilitate overhauling of the Carter carburetors These tools are available under SE 1639 and are shown in Fig 4 Proper selection of carburetor flange gas ketis necessary when installing the carburetor on the manifold see Fig 5 If the carburetor is used in conjunction with a sandwich governor governor mounted between carburetor flange and manifold the gasket having four small holes is used Where no governor is used the slotted gasket is used The slots in the gasket provide leads to the vacuum passage leading to the step up piston cylinder Either gasket can be used between the gov
29. and screws fast idle arm throttle shaft washer throttle lever idle port rivet plug idle adjusting screw and spring gasket attaching screws 3 low speed jet throttle shaft seal spring Group all parts controlling the high speed circuit Metering rod metering rod jet pin spring Group all parts controlling the pump cir cuit pump lifter link pump connector link throttle shaft arm assembly metering rod arm assembly pump diaphragm housing pump diaphragm assembly pump diaphragm spring diaphragm spring retainer pump intake strainer upper pump spring upper pump spring retainer pump disc check pump disc retainer pump disc retainer ring diaphragm housing screw and washer as sembly 4 Group all parts controlling the choke cir cuit choke valve and screws 2 choke shaft and lever assembly fast idle connector rod and spring choke tube clamp assembly air horn attaching screw and washer assembly 7 pin spring 2 Install throttle shaft seal and retainer in flange casting Install fast idle arm washer and lever as sembly on throttle shaft slide shaft into place and install throttle valve Carter trademark should go toward the idle port when viewed from manifold side of flange Tap valve and hold in place with finger be fore tightening screws Install idle port rivet plug and idle adjusting screw and spring Attach flange assembly to pong casting Use new gasket Install low speed jet assemb
30. bly R a Throttle shaft Y pump arm er assembly A 22899 PAGA a Choke p B Choke valve P od 1 i screws valve lever ring A 22914 MODEL YF SERVICE PROCEDURE To Disassemble l 2 10 11 12 13 14 15 Remove pin springs fast idle connector rod spring and rod Fig 1 Remove air horn and bowl cover attaching screws 7 and choke tube clamp assembly Fig 1 Remove air horn assembly and gasket Remove pump disc retainer ring using knife tip retainer and pump check disc Fig 2 Remove throttle shaft arm assembly pump connector link shaft seal spring dust seal washer and felt dust seal Fig 7 Loosen diaphragm housing attaching screw and washer assemblies 4 and lift out entire pump and metering rod assembly Figs 3 and 4 Remove diaphragm housing attaching screws pin spring metering rod upper pump spring retainer upper pump spring metering rod arm assembly and pump lifter link Fig 4 Remove diaphragm spring retainer spring and pump diaphragm assembly Fig 4 Carefully remove pump intake strainer from housing using tip of knife blade Remove metering rod jet Remove low speed idle jet assembly Do not remove pressed in parts such as nozzle pump jet or anti percolator air bleed Fig 2 Remove body flange attaching screw 3 body flange assembly and gasket Fig 1 Remove idle adjustment screw spri
31. d to the diaphragm 35 As the air bleed to the diaphragm is reduced it permits the suction supplied by the orifices 37 and 38 in Fig 8 to operate the diaphragm As this suction increases the diaphragm power overcomes the tension of the governor spring 46 in Fig 7 and takes over full control of the throttles The engine governed is then held constant by the valve 47 being balanced between the pull of centrifugal force actuated by the rotation of the shaft 43 and the tension of the spring 49 in Fig 7 sSIISSI Ue I Il SS T SEE NN Lo dg O L TATE T e D WII AN L 4 INN A 22476 Any slight change in speed or engine load will cause the governor valve 47 to act immediately either to increase or decrease the amount of air bleed through orifice 50 which in turn causes an instant response from the diaphragm to increase or decrease the throttle opening L LINE MOTOR TRUCK SERVICE MANUAL When the accelerator is released the control is taken away from the governor by the external throttle lever and the governor connecting spring 40 then closes the throttle to bring the engine to any desired lower speed NOTE The governor adjustments have been set at the factory to operate the engine at the proper recommended speed It is not likely that the adjustments will change once they are set Governor Adjustments and Service Hints To adjust the governor cut off speed proceed as follows
32. e lever if bent or if ball stud is worn Re place shaft if worn or accelerating pump lever if loose or if clutch assembly is loose Replace housing if shaft bearing is down or if housing is damaged Install throttle operator shaft in housing and place throttle lever in position ball stud facing toward carburetor and tighten lever clamp screw Install the two throttle operator lever shaft housing mounting screws and place gasket in position Hold the assembly with throttle Iever ball stud up and assemble to throttle body as shown in Fig 23 Tighten housing mounting screws Note Check the assembly if correct the throttles will close when lever is turned counter clockwise Releasing lever should permit governor operating spring to pull throttle into full open position THROTTLE LEVER STOP SCREW Place spring over stop screw and install as sembly in throttle body Holding throttle plates closed turn the throttle stop screw in until throttles open enough to allow a 003 feeler to pass freely between edge of plate and wall of bore Main Body and Throttle Body Assembly l Le Install new main body to throttle body gasket Place main body in position on throttle body and assemble with the three mounting screws This operation is accomplished by reversing the procedure outlined in Fig 4 and Fig 42 Tighten the three mounting screws Donated by John 4 Susan Hansen For Personal Use Only FUEL SYS
33. eee ig H B 2 E Power cesa ee wa A AE A 050 a High Speed Bleed Tr 035 65 DR Main Well Bleed Upper lt lt lt ess 025 72 DR Main Well Bleed Lower 025 72 DR Idle Well Restriction o 031 68 DR e Idle Air Ble d 59 99 wo OHSS RR 055 54 DR R Idle Transfer Hole 0465 56 DR z Idle Discharge Hole 0465 56 DR Idle Adjusting Screw PAUSE Screw Ld CM Accelerator Pump Spring 38R 452 035 Wire Accelerator Pump Link 33R 207 Accelerator Jet ae os o o R N 033 Ruel Heal comisario 082 Used With Governor en n Yes Yoa 1 61 103 se32d uiuawajddns E56 HOUVA Z1 SLO YOIIYIWY dO 631YV16 CALINAN Ni GaLNitd Donated by John amp Susan Hansen For Personal Use Only SPECIFICATIONS COVERING HOLLEY CARBURETOR MODEL 885 FFG USED ON RD 406 AND RD 450 ENGINES FUEL SYSTEM SPECIFICATIONS ENGINE MODELS RD 406 RD 450 CARBURETOR HOLLEY MODEL NUMBER 885 FFG 885 FFG Float Level 1 2 Below Top of Fuel Bowl 1 2 Below Top of Fuel Bowl Venturi 1 7 32 1 1 4 Main J l 60 Std Alt 61 Std Alt ain OILS 2 6462S eo CERES wr de UR 58 High Alt 59 High Alt Idle Tubes 54 C
34. ernal lever 53 on the throttle shaft by the Aa iS IN gt t Tal sh 3 23 N SS ET zl ees Saman x CNN KO NS gt NG 4 ab f ARATE E C NS 3 0 accelerator spring as shown in Fig 8 At s N Z idling speed the governor valve 50 in Fig 7 54 53 38 A 22240 is held away from the air bleed orifice 50 by the spring 49 which is fastened to the governor Fig 8 adjusting screw 48 As the accelerator is PRINTED IN UNITED STATES OF AMERICA Donated by John 4 Susan Hansen For Personal Use Only FUEL SYSTEM Section D Page 6 SRO ow gt SSS N fa B SI NY E NIS NES LL AZ IMP NS E IP AFAPAVAPAP AF AFP TI 4 45 Ey 46 wee A 0077 Fig 9 moved to and held in the full open position to increase the engine speed the governor spring 46 in Fig 7 pulls the throttles to the wide open position to remain there until the engine r p m has reached the predetermined governor cut off speed At this point the governor mechanism which has kept pace with the engine speed is ready to go into action and take over control of the throttle causing the accelerator system to become ineffective for further engine speed increase Theaction of the mechanism is that when the engine speed increases the gover nor valve 50 in Fig 7 stretches the spring 49 and moves toward the air bleed orifice 50 thus restricting the blee
35. ernor and manifold L LINE MOTOR TRUCK SERVICE MANUAL a Ar MIM INTERNATIONAL VV 2 Fig 4 Service Tools See list below Service Tools A special set of tools is provided to facil itate overhauling of the Carter carburetors see Fig 4 These tools are as follows SE 1639 Carter Carburetor Service Tools Set consists of SE 1639 1 to 1639 13 inclusive SE 1639 1 Grip handle for sockets No T 109 51 SE 1639 2 Handle bar for grip handle No T109 53 SE 1639 3 Screw driver bit 5 16 No T 109 57 SE 1639 4 Screw driver bit 1 4 No T109 58 SE 1639 5 Screw driver bit 3 16 No T 109 59 SE 1639 6 Socket double hex 9 16 No T109 69 SE 1639 7 Socket double hex 5 16 No T 109 64 SE 1639 8 Ball retaining inserter tool No T109 75 SE 1639 9 Rivet extractor tool No T109 43 SE 1639 10 Floatlevel gauge No T109 50 SE 1639 11 Main vent tube tool No T109 195 SE 1639 12 Ball retaining ring removing tool No T109 56 SE 1639 13 Metal box for SE 1639 tools Carburetor flange gaskets ring O O O O Used with governor A 23443 Used without governor Fig 5 d INTERNATIONAL Donated by John 4 Susan Hansen For Personal Use Only L LINE MOTOR TRUCK SERVICE MANUAL FUEL SYSTEM Section D Page 1 HOLLY MODEL 852 FFG CARBURETOR Choke plate Choke lever Air horn and float bowl cover assembly Throttle lever Diaph
36. ersonal Use Only L LINE MOTOR TRUCK SERVICE MANUAL FUEL SYSTEM Section A Page 1 FUEL SYSTEM GENERAL VAPOR LOCK The Service Parts Department has avall able an electric fuel pump for use on trucks which have given trouble with vapor lock but they cannot furnish material other than shown in Fig 1 because the installation will have to conform to individual requirements ZG To coil side of ignition switch il Electric fuel pump switch Carburetor Mechanical fuel pump Auxiliary electric fuel pump Fuel tank Main fuel Jine A 23442 Fig INSTALLATION ELECTRIC FUEL PUMP Fig 1 illustrates a hook up that is adapt able to any type of fuel system The location of the fuelline from the elect ric pump should be on the outside of the frame rail opposite the exhaust system and if neces Sary carried across thefront cross member to the carburetor Considerable freedom can be exercised in locating the lines always keeping in mind that they should be away from the exhaust system and not exposed to hazards that will result in their being damaged The use of loom is rec ommended where protection from radiated heat 15 required Should the electric pump be located where it may be damaged from stones etc a simple shield can be readily installed to supply the necessary protection The following discussion on vapor lock is for the purpose of providing necessary infor mation to diagnose and
37. etor whichever is easier to reach Then turn the engine over a few times using the starting motor It is best to turnoff the ig nition switch If gas spurts from the pump or the outline line the pump gas line and tank are OK If no gas flows at all or if only alittle gas flows do the following 1 Look for a leaky bowl gasketseat In stall a new gasket if you are not sure 2 Remove and clean the gas strainer which is inside the pump bowl 3 Look for loose line connections Check allthe way back to the gas tank Tighten all connections 4 Look for aclogged fuel line Blow out with compressed air 5 Make sure that all cover screws on the pump are tight Make sure that the external plugs over pump valves are tight 6 Inspect the flexible fuelline for breaks or porous condition If correction of the above six items does not place the pump in operating condition it should be removed for replacement or overhaul PRINTED IN UNITED STATES OF AMERICA Donated by John amp Susan Hansen For Personal Use Only L LINE MOTOR TRUCK SERVICE MANUAL FUEL SYSTEM Section A Page 3 ENGINE GETTING TOO MUCH GAS More often than not an oversupply of gas oline is caused by trouble somewhere else not in the pump So first check the following Defective automatic choke Excessive use of hand choke l 2 3 Punctured carburetor float 4 Defective carburetor needle valve 5 Loosely connected
38. expell the va por during which time the following cycle is being established a Reduced engine speed because of lack of fuel b Reduced fuel pump speed with propor tional loss of pumping ability c Increased fuel temperatures and re sultant increase in vapor formation resulting in reduced fuel delivery and further reduction of engine speed The continuation ofthe cycle willultimately result in the complete cessation of gasoline de livery TYPE OF FUEL VAPOR LOCK The use of a highly volatile gasoline such as furnished in Winter weather will produce vapor lock under conditions where a less vola tile or Summer gasoline would be satisfactory HOW TO DIAGNOSE VAPOR LOCK A vapor lock in the system permits the gasoline level in the float bowl to become low or even dry causing a lean mixture which is evidenced by the following operating character istics a Lack of power on full throttle or soft ness and flat spots on part throttle op eration b Stalling on idle when engine is hot c Inability to start a hot engine Donated by John amp Susan Hansen For Personal Use Only FUEL SYSTEM Section A Page 2 L LINE MOTOR TRUCK SERVICE MANUAL PROPER USE OF ELECTRIC FUEL PUMP FOR VAPOR LOCK When the first indications of vapor lockare observed the electric pump Should be brought into operation and uponregaining the lostengine speed should be shut off thus giving the stand ard mechanical pum
39. get a solution to the problem WHAT IS VAPOR LOCK When asection of the fuel system becomes filled with gasoline vapor causing either partial or total disruption of fuel service to the car buretor it is said to be vapor locked PRINCIPAL SOURCES OF HEAT VAPOR LOCK The fuel pump is generally the part of the fuel system where the greatest rise in fuel temperature occurs because of heat derived from the following sources PRINTED IN UNITED STATES OF AMERICA a Heat conducted from crankcase and camshaft b Heatreceived from hot oil splashedin to pump body for lubricating purposes c Radiated heat from exhaust manifold d Heat received from under hood air It is for these reasons thatthe electric fuel pump is mounted on the outside of the frame rail The fuel line from the fueltank to the reg ular mechanical pump is under a depression or more commonly known as suction which lowers the vaporizing or boilingpoint of aliquid This makes it particularly bad to have it located close to the exhaust system By locating the electric fuel pump close to the fuel tank a greater percentage of the system is under pressure which increases the vaporizing or boiling temperature of the gasoline WHEN AND WHY OF VAPOR LOCK Vapor lock occurs in hot weather with a hot engine when the fuel requirements are at minimum such as idling after a hard run When the maximum amount of fuel is again re quired the fuel pump must first
40. he accelerating pump opera tor rod and piston assembly Fig 27 Disassemble the pump rod and piston by compressing the spring and remov ing the pump rod from the piston slot Fig 28 Remove accelerating pump operator rod seal Use narrow blade screw driver and pry out felt retainer and remove felt Fig 29 Choke plate ie Screws Fig 20 PRINTED IN UNITEO STATES OF AMERICA A 22223 WE Throttle F operator haft housing assembly Retainer screws A 22166 Fig 23 Donated by John amp Susan Hansen For Personal Use Only FUEL SYSTEM AMA Section D L LINE MOTOR TRUCK SERVICE MANUAL age Pump rod de L L L V D 2 Ed E a y SLOT TIRES ATTI E rm E E t mit a SET fy x ast e NP m ING x KS d l Less fuel 2 Average 3 More fuel A 22529 ba Fig 24 4 22215 n X NE sae Ld c P n y Gasket A 22212 Throttle operator shaft assembly en Bak 7 Seal retainer A 21585 Narrow blade screw driver A 22454 Fig 29 FUEL SYSTEM L LINE MOTOR TRUCK SERVICE MANUAL 2 age AMIN Fig 30 Remove the two brass air bleed plugs and gaskets located at the top of the main discharge nozzle bars Fig 31 Remove the two nozzle bar clamp screws and lockwashers located nearest the fuel reservoir and re move clamp Fig 32 Remove the accelera
41. ingers Be sure to hold throttle open while removing spring Remove cotter pin holding diaphragm rod to governor lever Fig 48 Fig 49 Remove governor lever retainer nut and lockwasher SE 1190 9 wrench fits this nut Fig 50 Remove governor lever from throttle shaft Fig 51 Remove the three screws and lock washers that hold governor housing ue to throttle body eee Y Governor spring Fig 52 Remove the governor housing from the throttle body and remove gasket Note The throttle shaft leather seal and washer will usually adhere to governor body but were placed on shaft to show correct assembly Fig 47 Diaphragm rod Cotter pin Governor lever A 22151 Cover plate screws d A 22184 Governor lever retainer nut A 22169 lt A 22182 Donated by John amp Susan Hansen For Personal Use Only FUEL SYSTEM L LINE MOTOR TRUCK SERVICE MANUAL go We baga Fig 53 Remove coiled seal retainer spring i Throttle shaft from throttle body Fig 54 Remove two idle adjusting screws and springs Fig 55 Mark the throttle plates 1 and 2 and also mark the same number on the casting flange as shown Scribe lines across the full width of the plates against the shaft This will assure installation in their proper barrels and in correct position when reassembling x Governor lever Governor to throttle body screws Throttle f N
42. ion Do not merely take a customer s word on mileage run a gas test with a scientific mileage tester Check float level in carburetor bowl and make sure the fuel pump pressure is not excessive Then if there is still cause for complaint the various points as outlined above should be carefully checked over Pump link A 22654 Fig 6 Showing adjustment provided for accel erating pump stroke No hole shortens pump stroke No 2 length increases pump stroke The No 2 hole is the intermediate and recom mended position GOVERNOR MODEL 1174 This engine speed governor has been designed and engineered as an integral part of the Holley Carburetor The governor is a vacuum con trolled device featuring all the advantages ofa Donated by John amp Susan Hansen For Personal Use Only FUEL SYSTEM L LINE MOTOR TRUCK SERVICE MANUAL Section D Page 5 NN 43 y J 49 by Ng aT EY i i gt AN s gil UTR SS NM SS a 1 4 EL ISI si HD AN lt 2 NA HR EN f AN LESA D USE GU A 22469 Fig 7 Details of governor Spinner or rotor nousing is located at distributor The diaphragm chamber 33 in Fig 9 is con nected to the governor valve air bleed orifice 50 in Fig 7 by means of a conventional pipe line 34 The air bleed supply enters the rotor housing 52 Fig 7 from a pipe line 42 at tached to the engine air cleaner or carburetor as shown in Fig 7 mechanical governor without
43. itch The engine must be completely stopped to adjust this governor 2 Remove the adjusting hole plug seal located at the side of the governor housing Do not break the pipe con nection seal Remove the adjusting hole plug Figs 68 69 3 Turn engine over with hand crank ig nition switch OFF until the adjusting screw in the end of the enclosed rotor appears at the plug hole 4 Insert a screwdriver through the open ing from which the hole plug was re Fig 70 moved and turn the screw clockwise to increase speed or counter clock CAUTION Excessive engine speeds cause wise to decrease engine governed undue strains and rapid wear on engine parts speed Fig 70 One turn of the screw therefore the governor must not be adjusted to will affect the governed speed approx allow the engine to exceed the maximum re imately 150 engine r p m commended r p m AINA y Donated by John 4 Susan Hansen For Personal Use Only L LINE MOTOR TRUCK SERVICE MANUAL FUEL SYSTEM Section E Page 1 AIR CLEANERS Cover retainer nut KA A 21733 Fig Air Cleaner Bonnet type mounting Description The construction of the oil type aircleaner Figs 1 and 2 is such that uncleaned air is drawn into the upper portion of the unit and then drawn downward at high velocity Just above the oil reservoir the direction of air travel is suddenly reversed and this reversal of airflow causes the larger particle
44. l If the leather is not a snug fit against the cylinder wall fuel will leak by the piston on acceleration causing a weak discharge To clean the accelerating pump system remove piston assembly and check ballretainer and check ball from bottom of cylinder Remove pump discharge nozzle and valve 28 Fig 3 Re move pump discharge needle valve All chan nels can then be cleaned of all foreign matter by flowing out with compressed air The small holes or restrictions in the discharge nozzle should deliver a fine solid and round stream When the system is in good condition a quick steady stream will flow from the discharge out let the instant the throttle is opened MAIN FUEL SYSTEM To check for trouble at intermediate speeds be sure all gaskets are tight Remove main jets 13 Fig 2 and check size in accordance with specifications Cleanmain jets main jet passages and main discharge nozzle with compressed air NOTE Never attempt to clean any of the small holes or restrictions by forcing any object through them This is apt to enlarge the hole or distort the shape and change the calibration HIGH SPEED COMPLAINTS For high speed complaints check the power valve 17 Fig 2 as well as the main jets 13 in accordance with the above instructions Clean all passages with compressed air Check the fuel pump pressure to be sure it is sufficient to maintain fuel level in the bowl Check float travel to insure full opening of
45. l Remove the seal from the screw 51 that will be found on the side of the governor housing 52 in Fig 7 2 Remove the screw from the housing 3 Rotatethe engine until the end of the governor rotor 41 in Fig 7 which carries the ad justing screw 48 is in line with the hole from which the screw 51 was removed 4 With a suitable screw driver turn the ad justing screw to the RIGHT to INCREASE the engine governed speed or to the LEFT to DECREASE the speed NOTE Where the governor has been dis assembled andserviced after reassembling turn the adjusting screw 48 to the right until it stops then turn the screw to the left three full turns Final adjustment is then made after the governor has been assembled to the engine as outlined above in operation 4 HOLLEY CARBURETOR AND GOVERNOR OVERHAUL The carburetor and governor can be overhauled with ordinary tools Clean all loose dirt from carburetor assembly before proceeding with the following instructions CAUTION Do not immerse the carburetor as sembly in cleaning solvent as the solution may cause damage to leather seals and governor diaphragm Do not direct compressed air stream into air vent tubes in air horn as air pressure will damage float MAIYA Donated by John amp Susan Hansen For Personal Use Only FUEL SYSTEM PN dme L LINE MOTOR TRUCK SERVICE MANUAL Section D AN age Air horn and float bow cover assembly
46. lever 32 The function of the accelerating assembly is to temporarily en rich the mixture for rapid acceleration The fuelis drawn into the pump chamber 29 through pump inlet check valve 25 on the upward stroke of pump piston 30 when closing the throttle When the throttle is opened the pump piston 30 moves downward closing the pump check valve 25 and forcing the displaced fuel through passage 24 to raise the pump discharge valve 28 The accelerating fuel charge then goes around the valve and out the pump discharge nozzle 26 A slot in the pump piston stem allows the pump operating rod 31 to overrun the pump piston 30 when the throttle is opened suddenly This overrun causes the pump piston to be subjected to the pressure of the spring 27 thereby giving a prolonged discharge of the accelerating fuel The accelerating pump is provided with an ad justment for varying the quantity of the accel erating charge This adjustment is made by changing the position of the pump link 30 in the holes of the operating lever 32 The position farthest away from the pivot point is the cold weather setting since it gives the greatest discharge The middle position is the average setting and the position nearest the pivot is used under conditions of very hot weather ADJUSTMENTS AND SERVICE HINTS TOOLS REQUIRED This carburetor can be cleaned or repaired without the use of special tools MIN INTERNATIONAL
47. ly Donated by John 4 Susan Hansen For Personal Use Only FUEL SYSTEM Section B Page 4 Zt 28 29 30 31 32 33 34 35 36 37 38 Install pump intake strainer in pump dia phragm housing and carefully press into recess CAUTION If strainer is even slightly damaged a new one must be used Install pump diaphragm assembly in dia phragm housing then install pump dia phragm spring lower and retainer Install pump lifter link metering rod arm upper pump spring and retainer Install metering rod jet no gasket is used with this jet Install diaphragm housing attaching screws 4 in the diaphragm housing making sure the edges of diaphragm are not wrinkled Lower into place and tighten screws evenly and securely Install throttle shaft seal dust seal washer and shaft seal spring Install pump connector link in the throttle shaft arm assembly Install throttle shaft arm assembly on throttle shaft guiding connector link into pump iifter link hole CAUTION Linkage must not bind in any throttle position If binding occurs loosen clamp screw in throttle arm adjust slightly and retighten screw Install pump check disc disc retainer and lock ring Install metering rod and pin spring Con nect metering rod spring Metering Rod Adjustment Be sure flat of metering rod arm is parallel to flat of pump connector link before proceeding with metering rod adjustment With
48. ng idle port rivet plug throttle lever assembly washer fast idle arm valve attaching screws 2 and throttle shaft Then remove throttle shaft seal by prying out seal re tainer Do not remove vacuum passage orifice pressed in Remove float pin float and needle and seat assembly from air horn casting Fig 5 Remove choke valve screws and choke valve Unhook choke spring and slide shaft from housing Do not remove balance vent tube NOTE In normal service choke lever assembly will not require replacing How ever if it has been bent or otherwise damaged requiring replacement proceed as follows Pry off choke lever retainer ring and remove lever assembly Fig 8 PRINTEO IN UNITED STATES OF AMERICA Donated by John 4 Susan Hansen For Personal Use Only L LINE MOTOR TRUCK SERVICE MANUAL 16 FUEL SYSTEM Section B Page 3 Wash all parts in carburetor cleaning solution and blow out passages with com pressed air Do not immerse diaphragm assembly pump check disc or seals in cleaning solution Inspect all parts for wear or damage and replace if necessary Always use new gaskets To Reassemble 17 18 19 20 2l Boe 23 24 25 26 Group all parts controlling the float cir cuit float float pin needle and seat as sembly air horn gasket Group all parts controlling the low speed circuit throttle shaft seals 2 and re tainers 2 throttle shaft throttle valve
49. on should be performed atearlier intervals under dusty operation even daily under severe conditions When servicing the oil type air cleaner re move the oil cup or reservoir and clean free of old oil and dirt Wash the filtering mesh or element in kerosene then dip in clean oil and allow the excess oil to drain from the element Air cleaners should be serviced with same grade oil as used in the crankcase and the oil cup filled to the level indicating beads inthe cup See chart below for approximate capacities Air cleaner connections mustbe maintained in a tight and leak proof condition Otherwise uncleanedair will be allowed to enter the engine OIL CAPACITY PINTS Cont R 6602 SD 220 240 Donated by John amp Susan Hansen For Personal Use Only
50. ousing 3 Perch Position 3 Perch Position Governor By Pass Jet Hole A 028 028 Governor By Pass Jet Hole B 052 052 Maximum No Load Speed 2950 R P M 2800 R P M AAAS NONYL YO LOW ANITYU Governor Rotor Valve and Housing Assembly IH Part Number 114510 R91 114510 R91 Air Cleaner Oil Capacity Specifications covering the Hat type air cleaner used in conjunction with the Holley 1904 Carburetor SD 220 ENGINE SD 240 ENGINE BD 269 ENGINE BD 282 ENGINE p 23 4 suotje21j122dg NALSAS TANA NS YOIHIAY 4O S31v1S GALINA Ni O31NISg Donated by John amp Susan Hansen For Personal Use Only gt AAA ELLA L L FUEL SYSTEM SPECIFICATIONS ENGINE MODELS SD 220 SD 240 BD 269 RD 372 RD 406 RD 450 Cont R 6602 lt o O FUEL PUMP AC Model number 1539537 1539537 1539501 1539513 1539513 1539513 1538259 2 Typ PP AF ae AT it da sesser sassu iras 3 to 4 1 2 3 to 4 1 2 4 to 5 1 4 4 to 5 1 4 4 to 5 1 4 a A lbs at i lbs at lbs at lbs at lbs at ting pressure l l i i POTONE Parser te 3500 engine 3500 engine 3500 engine 3600 engine 3600 engine 3600 engine 2 r p m r p m i p m r p m r p m p m rep m Un FUEL PUMP CARTER s Model number M 737S M 737S EX112 78 cee 4 asas ata cua 3 to 4 1 2 3 to 4 1 2 3to 4 1 2 Ll E R lbs at lbs at ips GE TY
51. p an opportunity to rid the regular fuel system of vapor This method of operation may have to be repeated several times before the mechanical pump will supply suffi cient fuel after which the use of the electric pump is not required however instubborn cases continous operation may benecessary It should be noted that shut off valves are not shown on the sketch as it isdesired tomake theauxiliary system as flexible as possible to accomodate either continous or intermittent operation making it unnecessary to stop the engine NOTE If the electric pump is not required regularly itshould be operated every few days to prevent the stagnant gasoline from forming gum TRUCK STORAGE PREPARATION OF FUEL SYSTEM When placing trucks in storage remove all fuel from the fuelsystem If fuel is not entirely removed a gumlike substance will be deposited on all parts contacted by the fuel and will seri ously affect operation of the carburetor and fuel pump All standard grades of gasoline have a small gum content which is not sufficient to cause any trouble under ordinary conditions However when allowed to stand for a period of two or more weeks the gum will increase toa point where adeposit is formed onthe surfaces which it contacts This deposit when dry has a hard varnishlike appearance Gum deposits may completely alter cali bration of the carburetor for itwillpartially or completely plug the jets or cause the power jet valve and
52. p cannot draw fuel into the bowl To remedy this install a new gasket and see that bowl seats squarely Tighten clamp screw securely with the fingers only If fuel pump bowl still does not fill the trouble may be due to an air bound condition In this case the bowl should be loosened slightly so that air can escape and by blowing in the gasoline tank filler neck fuel will be forced into the pump Then tighten bowl securely and start engine Donated by John amp Susan Hansen For Personal Use Only INTERNATIONAL Donated by John amp Susan Hansen For Personal Use Only L LINE MOTOR TRUCK SERVICE MANUAL FUEL SYSTEM Section B Page 1l CARTER MODEL YF CARBURETOR Description The Carter carburetor model YF for the 220 and 240 Silver Diamond engines is essentially the same as conventional carburetors in that it has a high speed fuel circuit low speed cir cuit and accelerating pump circuit There is however a departure in the method of controlling the fuel flow on part throttle wide open throttle and through the accelerating pump circuit as compared to carburetors pre viously used A calibrated metering rod Fig 4 fits into the main jet It becomes effective at low part throttle speeds and automatically positions itself according to the throttle opening thus producing proper fuel flow throughout part throttle and wide open throttle The heart of the carburetor is the diaphragm Fig 4 which ac
53. peed Changing the speed may make a slight change in the idling mixture In the event this occurs re adjust the screws as outlined above NOTE When adjusting the idle mixture itis important that both idle screws be set at ap proximately the same number of turns open otherwise the off idle performance may be erratic FAILURE TO IDLE PROPERLY AFTER AD JUSTING Be sure motor is tuned to speci fications Check for air leaks in intake mani fold gaskets carburetor body bowl and flange gaskets If the idle is erratic and not sensitive to ad justment check the float level in the float bowl Check the idle tubes 10 They must be tight on seat in nozzle bar casting 15 Fig 2 ACCELERATING PUMP ADJUSTMENT When the engine does not accelerate properly check the accelerating pump system for dirt If the pump inlet check valve 25 Fig 3 does not seat fuel will return to the float bowl instead Donated by John 4 Susan Hansen For Personal Use Only FUEL SYSTEM Section D Page 4 of discharging through the pump discharge passages 26 This can be checked by re moving the main body cover and operating the pump with a small amount of fuel in the bowl If the check ball is leaking air or fuel will bubble back into the float bowl through the inlet hole After cleaning this seat extreme care should be taken when reinstalling the pump piston to be sure the piston leather is not damaged and that it contacts the cylinder wal
54. r atmospheric changes keeps dirt out of the fuel system and reduces air cleaner clogging effects to a minimum POWER MIXTURE SUPPLY The power valve vacuum piston 18 and the spring 19 shown in Fig 2 are actuated by the vacuum below the throttle plate 5 which communicates with the top of the piston 18 through passage 20 L LINE MOTOR TRUCK SERVICE MANUAL At idle the vacuum is the highest and it de creases as the load of the engine increases The piston 18 actuated by vacuum and the spring 19 are held in the up position which allows the valve 17 to remain closed until the vacuum drops to approximately 7 5 to 6 5 inches of mercury Below this vacuum the piston force is not great enough to resist the compressed load of the spring 19 and thus opens the power valve 17 Under load as in climbing hills etc the vacuum drops because it becomes necessary to open the throttle wider in order to maintain speed When the vacuum drops below 7 5 inches of mercury the power valve is opened by the piston stem The fuel then flows into the power valve chamber and through the restriction 21 into the main well 6 and is discharged together with fuel from the main metering system This gives the additional fuel required for high speeds for heavy loads and low speeds at full throttle Accelerating Pump The accelerating pump shown in Fig 3 is con nected to the throttle shaft by means of link 33 and operating
55. r plug gaskets in top of nozzle bars Install bleeder plugs in place and tighten ECONOMIZER VALVE Replace valve if spring is weak or if the valve stem is bent Place a new gasket on valve body and as semble valve in place Fig 40 ACCELERATING PUMP Examine pump piston operator rod operating spring leather cup and cup expander spring Re place any worn bent or distorted parts Assemble pump rod spring and retainer to piston and install the pump assembly in the pump chamber of the main body casting Be careful not to damage the leather as it is entered into the pump chamber PUMP OPERATING ROD STUD Replace stud if bent or badly worn Using a small accurate fitting open end wrench 1 47 tighten stud to rod Donated by John amp Susan Hansen For Personal Use Only MIMA FUEL SYSTEM Section D L LINE MOTOR TRUCK SERVICE MANUAL Page 20 WV 3 THROTTLE PLATES Replace throttle plates if they are nicked or otherwise damaged To install plates place throttle body on bench with the manifold mounting flange up and the threaded end of the throttle shaft to the left Rotate the shaft until the countersunk holes in shaft are facing the idle adjusting screw bosses 20 Assemble main jet plugs and gaskets to casting Blow out casting thoroughly with compressed air Assemble air horn to main body Recheck the float setting using gauge Holding as sembly gasket in place assembly air horn to main body and
56. ram and governor assembly Idle adjusting Throttle stop screws screw A 22549 Fig Description The Holley Model 852 FFG carburetor is a dual downdraft carburetor of the plain tube type designed for use on engines of approximately 260 to 390 cubic inch displacement All of the metering jets and passages are located in the center of the main body which provides for correct metering of fuel and air at all practical operating angles The carburetor fuel system is fully balanced and sealed the air for all vents and bleeds being taken from the main air entrance of the carburetor thus only air which has passed through the air cleaner is admitted to the carburetor The governor actuated throttle mechanism is an integral part of the carburetor designed to provide the needed power required for moving the throttle to governing speeds and is con trolled by a separately driven governor rotor The combination of these two units has been engineered to give instant response and accurate governing A power valve provides additional fuel for high power operation and a throttle actuated ac celerating pump provides the necessary fuel for fast engine pick up A throttle lever which is self locking and self positioning is incorporated in this carburetor This dual carburetor can be considered as two carburetors built into one unit There are separate venturi tubes idle tubes and throttle PRINTED IN UNITED STATES OF AMERICA A 224
57. resorting to lengthy and complicated linkage The governor can be cleaned and serviced without the use of Special tools The governor is made up of two units see Fig 7 The control at the engine end of the governor Vacuum to the diaphragm 33 Fig 7 is sup consists of a governor valve 47 an adjusting Bed beans QUAL DUO 37 a screw 48 a spring 49 assembled 38 as shown in Fig 8 Channel 37 opens into rotor 41 which revolves at one half the engine ihe carburetor above the theoitle plate and speed in a housing 52 attached to an engine channel 38 below the throttle plate These driven shaft 43 The controls at the carburetor two openings are connected by iene 29 end of the governor unit consist of a diaphragm Fig 8 which in turn is directly connected nga 35 which is connected to the governor lever chongel 36 as shown in Fig 9 The vacuum is 45 i a short rod and a tension spring 40 controlled by the governor by pass channel which is also attached to the governor lever 45 jets 39 instead of the variable restriction and tends to hold the throttle open formerly used 31 29 A detailed description and the operation of the above mentioned features follows j KON VY D p Governor Operation J SIZZE When the engine is running at idling speed the throttle is controlled by the external lever 2 Fig 8 and the pin 54 which is held against the int
58. s of dirt to fall into the oil The partially cleaned air then travels upward through an oil moistened filtering ele ment where any remaining dirt and dust par ticles are removed The cleaned and purified air then leaves the air cleaner and enters the carburetor The air cleaner on Super Red Diamond En gines is located in the conventional under the hood position However the air taken into the air cleaner is drawn through a special hood opening Fig 3 The purpose of this outside intake is to draw in cooler outside air during hot weather operations when high under hood temperatures would otherwise make available to the engine only expanded air with low oxygen content By drawing in cooler air with greater oxygen volume per cubic foot volumetric effi ciency is increased and the engine produces the greater horsepower for which it is designed In cold weather when under hood air tem perature is more desirable for efficient engine operation air intake is easily changed to draw air from under the hood Servicing Air Cleaners The necessity for cleaning and servicing of oil type air cleaners depends entirely upon operating conditions as to dust dirt etc PRINTED IN UNITED STATES OF AMERICA Mounting bracket lamp A 23444 Fig 2 Air Cleaner Bracket type mounting ie T A 22832 EMEN Fig 3 Under normal conditions oil type air cleaners should be removed and servicedevery 5000 miles The operati
59. san Hansen For Personal Use Only FUEL SYSTEM Section D Page 2 Re NG NG K ZN AN bo e SS N L 8 LORD NANA ANA Ay z ERR N A S 722 22 LZ T 19 A S NS A81 U U UUV UY Y GU L n JE LI NO L 25 24 MIO JU LEY Z177 Hi LT LI JT TA AA mai If SI 39 maa AULA Z L A S A 224 K Fig 3 the smoothest running and maximum idle r p m When seating the idle adjustment needle 4 excessive force should never be used as this may cause a groove to form on the needle point If this occurs the adjusting needle will have to be replaced in order to obtain a satisfactory idle adjustment Main Fuel System As the throttle is opened and the idle system becomes less effective the main discharge nozzle 15 in Fig 2 starts to deliver fuel This occurs at approximately 900 r p m road load Between 900 and 1200 r p m there isa definite blending of the idle and main fuel system In the above range all the fuel passes through the main jet 13 up through the main well 6 to angle channel 9 Here the fuel is atomized by the high speed bleed 7 and an additional sup ply of air is introduced to this mixture by the bleeder plug 16 before being discharged through the vertical passage 14 into the venturi The float bowl 12 Fig 2 is vented to the atmosphere through a balance tube 34 This system besides correcting float chamber air pressure fo
60. stalla new felt seal and retainer washer and stake as shown in Fig 66 JETS Replace jets if screwdriver slot orifice or threads have been damaged or otherwise mutilated Install jets in casting ACCELERATING PUMP INLET BALL CHECK Replace ball check if it is cor roded or nicked Drop ball into pump cham ber and work into seat housing Ball seat is located in cut away portion of chamber floor in which the bent end of the retainer fits RETAINER SPRING Replace spring if bent or twisted spring must lay flat Install spring in pump chamber keeping bent end of spring in line with ball check Then with a 5 8 diameter dowel pin of wood or fiber press the retainer in the groove at bottom of chamber Be sure bent end of spring is directly over the ball when in place PUMP DISCHARGE BALL CHECK AND SPRING Replace ball check if corroded or nicked Replace coiled spring if corroded or distorted Install ball check in pump discharge well Install coiled spring over ball check PUMP DISCHARGE NOZZLE AND GASKET Replace if damaged in any way Discharge holes must be clean blow out with com pressed air Place a new gasket in position on nozzle and hold assembly until ready to install bar clamp after main discharge nozzle bars have been placed in position PRINTED IN UNITED STATES OF AMERICA Donated by John amp Susan Hansen For Personal Use Only L LINE MOTOR TRUCK SERVICE MANUAL 9 10 11 12 13
61. te that the two choke plate screws are up set and must be filed flat before re moving to prevent breakage or strip ping of threads in shaft Economizer piston and stem assembly Air horn A 22486 ere M iL ud Se lu ans Float shaft Fig 18 Needle Gasket S 2 k X T Main body A ai Donated by John amp Susan Hansen For Personal Use Only L LINE MOTOR TRUCK SERVICE MANUAL FUEL SYSTEM Section D Page 9 Fig 20 Remove the two choke plate screws Remove choke plate shaft and felt packing Do not attempt to remove vent tubes Do not remove plug from end of choke shaft bars All removable parts have been stripped from air horn and float bowl cover assembly and should be kept together as a group ready for cleaning and inspection preparatory to reassembling Fig 21 Fig 22 Remove cotter pin holding acceler ating pump link in place Remove the two throttle operator shaft housing assembly retainer screws and remove housing assembly Fig 23 Remove accelerating pump link Note It is not necessary to remove the throttle operator shaft housing assembly when changing pump link to secure better engine performance or to adjust carburetor for climatic changes It was removed here to show the pump link lever more clearly Fig 24 Remove the throttle operator shaft assembly Fig 25 Fig 26 Remove the pump operating rod stud Remove t
62. the diaphragm spring The pump therefore de livers fuel to the carburetor only when the fuel pressure in the outletline is less than the pres sure maintained by the diaphragm spring This condition arises when the float needle valve is not seated and the fuel passage from the pump into the carburetor float chamber isopen When the needle valve in the carburetor float chamber is closed and held in place by the pressure of the fuel on the float the pump builds up pres sure until it overcomes the diaphragm spring This pressure results in almost a complete stoppage of diaphragm movement until further fuel is needed HOW TO DIAGNOSE FUEL PUMP TROUBLE Fuel pump trouble is of only two kinds Either the pump is supplying too little gas or in rare cases too much If the pump is supplying too little gas the engine either will not run at all or will cough and falter If the pump is supplying too much gas you will be able to see gasoline dripping from the carburetor or the engine will not run smoothly when idling Engines are hard to start when getting too much gas LOCATING FUEL PUMP TROUBLE ALWAYS CHECK WHILE THE PUMP IS INSTALLED ON THE ENGINE DON T TAKE IT OFF TO CHECK IT ENGINE NOT GETTING ENOUGH GAS If the engine is getting too little gas the trouble may be in the pump the fuel line or the gas tank First be sure that there is gas in thetank Disconnect the outlet line from the pump or the carbur
63. the inlet valve ALTITUDE OPERATION In some cases in high altitudes it may be necessary to use leaner metered main jets Usually a 5 or 10 leaner jet will compensate for any variation in altitude The metering jets are marked in thousandths of an inch of hole diameter thus the smaller the hole the smaller the number on the jet The main jets can be removed and installed without disassembling or removing the car buretor from the engine in the following manner l Remove the two main jet passage plugs and gaskets from the carburetor main body Removal of these plugs will drain the fuel bowl See Fig 38 L LINE MOTOR TRUCK SERVICE MANUAL 2 Remove the main jets using a screw driver having a screw starter blade See Fig 39 NOTE Ifthe jet fails to stick to the end of the removing tool but falls off into the fuel bowl it may be necessary to remove the air horn assembly 3 Install the main jets in the reverse of the removal operation No gaskets are used with the main jets NOTE Do not try to change the size of the power valve restriction 21 Fig 2 or the pump discharge nozzles 26 Fig 3 as this will cause erratic performance ECONOMY COMPLAINTS Changing jets rarely increases economy more than slightly and often ruins performance Make a thorough check on the condition of the motor with a compression gauge and make sure valves are in good condition In a vehicle check for dragging brakes or extra frict
64. ting pump dis charge nozzle and gasket Fig 33 Turn the casting upside down and catch the coiled spring and ball check resting in the pump discharge nozzle well Ee d gt A 22217 Remove the two idle tubes from the main discharge nozzle bars using a screw driver Fig 34 Main discharge nozzle bars 2 2 Fig 33 o s K Fig 3l PRINTED IN UNITED STATES OF AMERICA Donated by John amp Susan Hansen For Personal Use Only FUEL SYSTEM dr L LINE MOTOR TRUCK SERVICE MANUAL age Fig 35 Remove the remaining two nozzle bar clamp screws and remove clamp Retainer spring Fig 36 Remove the two nozzle bars and gaskets Fig 37 Use a wire having a short hook bent at 909 and remove the accelerating pump inlet ball check retainer spring from the bottom of the pump chamber Turn the casting upside down and catch the inlet ball check Fig 38 Remove the two main jet passage Ball check 2 plugs and gaskets Fig 39 Remove the two main jets using a Wire hook screw driver or SE 1190 2 jet wrench Fig 40 Remove economizer valve and gasket Fig 37 in bottom of fuel bowl using a screw driver with a wide blade Fig 41 Lay casting on its side and remove two throttle body to main body as sembly screws Pass screw driver through the carburetor mounting stud holes in base Plugs and gaskets A 22190 Fig 38 NA 22192 nn a Nozzle bars A 22189
65. tions Replace casting if defective Using compressed air blow out all governor channels Replace governor body etc Fig 67 Throttle Body LEATHER BEARING SEAL AND STEEL WASHER Replace leather seal if worn Inspect and assemble throttle body as follows 1 THROTTLE SHAFT BEARING Replace bearing if worn corroded or damaged in any way Bearing must rotate freely and be 24 free of gum and grit Install the bearing in the throttle body bearing boss on the gover nor side and with a brass rod lightly tap bearing in place 4 Note Bearing must be installed with letter ing on race visible after installation 5 2 THROTTLE SHAFT AND BEARING Re place the assembly if the shaft is bent or if threads are stripped Replace the as sembly if the bearing is corroded damaged 6 or worn or if throttle clutch is loose Bearing must be free from gum or grit Install throttle shaft and bearing Install throttle shaft bearing retainer or otherwise damaged Replace the steel washer if it is damaged Install leather seal in governor body so that the flat side of the sealis up Install steel washer over leather seal Install coiled retainer spring against bearing in throttle body Assemble governor body to throttle body Be sure gasket is correctly lined up before inserting the three assembly screws and lockwashers Draw assembly down tight GOVERNOR DIAPHRAGM AND ROD AS SEMBLY Replace assembly if diaphragm is burned torn
66. tuates the accelerating pump and the step up action for wide open throttle fuel mixtures The underside of the diaphragm is subjected to manifold vacuum by means of a channel down to the carburetor flange This channel is re stricted by a bushing in the flange in order to ob tain consistent and smooth performance and to promote extra long diaphragm life Any movement of the diaphragm results ina corresponding movement of the metering rod When the throttle is wide open the manifold vacuum drops sufficiently to allow the diaphragm to move upward thus shifting the metering rod to the wide open throttle step A chamber above the top of the diaphragm sup plies fuel for the accelerating pump circuit The diaphragm acts as a pump and the quantity of fuel discharged by the pump is controlled by the size of the pump jet or nozzle calibration Fig 2 and also the size of the fuel inlet hole to the chamber There is no check valve on the in let There is a check valve in the outlet channel near the pump jet to allow fuel to pass in an out ward direction only and also to prevent air from being sucked back into the chamber under cer tain conditions The pump jet is free to flow at all times generally starting at a part throttle engine speed of 1500 r p m and continuing throughout wide open throttle This carburetor has a unique feature in that no change in setting is required when it is used in conjunction with a sandwich type governor re
67. with air filter side facing up CHOKE SHAFT If shaft is bent or indi cates excessive wear use a new shaft stall choke shaft CHOKE PLATE Replace the plate if poppet valve assembly is damaged To facilitate installation of the choke plate rotate the choke shaft until the countersunk holes face the vent tubes Hold the shaft in this position and insert the choke plate from the float side of casting and with the poppet valve stem pointing away from vent tubes Center the plate in the bore and assemble to shaft using new screws The screws must be up set to lock them firmly in place Usea In 10 11 12 blunt center punch for this operation also support opposite side of shaft to prevent bending the shaft CHOKE LEVER Install on shaft with choke wire lock screw in swivel nut facing away from air horn casting and with outer edge of lever flush with end of shaft Hold choke plate in open position and tighten lever clamp screw FUEL INLET VALVE SEAT ASSEMBLY AND GASKET Whenever a carburetor has been in continual service for 10 000 miles or more and when carburetor is being overhauled for any reason whatso ever always replace original fuel inlet valve assembly with a complete new unit Install a new fuel inlet needle seat and gasket Wipe taper of needle valve with a soft clean cloth before inserting in valve seat FLOAT Replace float if it is corroded or damaged in any way If the lip on the float lever is
68. y Use a 5 16 socket wrench CAUTION Excessive tension will strip the threads on the shaft DO NOT DRAW THE NUT DOWN TOO TIGHT Push end of diaphragm rod through lever by placing a thin blade screw driver or similar tool under the rod Lock rod to the lever with a cotter pin Insert the cotter pin so that open ends point towards the dia phragm Spread the ends of the cotter pins around the rod GOVERNOR OPERATING SPRING Re place the spring if corroded or distorted Install operating spring with the fingers by hooking the loops over pins Be sure the loops drop into the grooves in the pins GOVERNOR BY PASS PASSAGE JETS Replace jets if worn or damaged Install the by pass jets in A and B channel Figure 62 Note The by pass jets have different outside diameters to aid in making correct installation PRINTED IN UNITED STATES OF AMERICA 13 GOVERNOR COVER AND GASKET Install a new gasket and install cover to governor body Install seal wire in cover screws and seal Throttle Body Idle Screws and Shaft Assembly L IDLE ADJUSTING SCREWS AND SPRINGS Replace screws if the tapered points are badly scored or bent Replace the springs if they are corroded or distorted Install adjusting screws and springs Note Turn screws in with the fingers until they are seated Do not use a screw driver Then back screws off seats one full turn THROTTLE LEVER AND THROTTLE OPERATOR SHAFT ASSEMBLY Replac

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