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BENDIX BW1421 User's Manual

1. DESCRIPTION AND OPERATION General The function of the air compressor is to provide and maintain air under pressure to operate devices in the air brake and or auxiliary air systems Description The Tu Flo 501 compressor is a two cylinder single stage reciprocating compressor with a rated displacement of 12 cubic feet of air per minute at 1250 R P M The Tu Flo 501 compressor is constructed from two major assemblies the head and the crankcase The head houses the discharge valving and is installed on the upper portion of the crankcase The crankcase is a one piece casting combining the cylinder block and the crankcase The upper portion of the casting houses the cylinder bores and inlet valving and the lower portion the crankshaft and main bearings Various mounting and drive configurations required by the numerous vehicle engine designs are obtained by bolting different mounting flanges end covers and base adapters to the crankcase Two horizontal governor mounting pads are located on either side of the upper portion of the crankcase to provide convenient governor mounting Two methods are employed for cooling the Tu Flo 501 compressor during operation The cylinder head is connected to the engine s cooling system while the cylinder bore portion of the crankcase has external fins for efficient air cooling FIGURE 1 VARIOUS COMPRESSOR MOUNTINGS All Tu Flo 501 compressors utilize the engine s pressuriz
2. Oil in gladhands 2 no O yes ae customer makes to how much oil did you find can be confirmed help the Technician LI Oil on ground or vehicle exterior in investigating amount described LI Short air dryer cartridge life replaces every L miles L kms or Q months x Note A confirmed com i plaintabove does NOT mean We will measure amount currently found when we getto step B of the test thatthe compressor must be Q Excessive engine oil loss amount described replaced Is the engine leaking oll cece eee Q no OQ yes The full BASIC test below will Is the compressor leaking Oil 00eee 2 no D yes investigate the facts LJ Other complaint LI No customer complaint BASIC test starts here STEP A Select one _ he Technician selects the air use category for the vehicle This Q This is a low air use vehicle Line haul single trailer with 5 or less axles or es decided which of the two accep LI This is a high air use vehicle Garbage truck transit bus bulk unloader or tance lines on the cup will be ae line haul with 6 or more axles Then go to Step B for the test below STEP B Measure the Charging System Contents Foran accurate test the 1 Park and chock vehicle on level ground Drain the air system by pumping the service brakes 2 Completely drain ALL the air tanks into a single BASIC cup 3 If there is less than one unit of contents total end the t
3. and Check List BW1279 Excessive system leakage causes the compressor to pump more air and also more moisture into the brake system Reservoir Draining System Without Air Dryer Routine reservoir draining is the most basic step although not completely effective in reducing the possibility of freeze up All reservoirs in a brake system can accumulate water and other contamination and must be drained The best practice is to drain all reservoirs daily When draining reservoirs turn the ENGINE OFF and drain ALL AIR from the reservoir better still open the drain cocks on all reservoirs and leave them open over night to assure all contamination is drained reference Service Data Sheet SD 04 400 for Bendix Reservoirs If automatic drain valves are installed check their operation before the weather turns cold reference Service Data Sheet SD 03 2501 for Bendix DV 2 Automatic Drain Valves It should be noted that while the need for daily reservoir draining is eliminated through the use of an automatic drain valve periodic manual draining is still required Alcohol Evaporator or Injector Systems Check for proper operation of these systems by monitoring alcohol consumption for a few days Reference Service Data Sheet SD 08 2301 for the Bendix Alcohol Evaporator Too little means the system is not receiving adequate protection and too much simply wastes alcohol As a general guide these systems should consume approximately 1 to 2 ou
4. 18 0 Reservoir Safety valve releases air 13 0 Test Procedures 1 Oil Leakage at Head Gasket 26 2 System Leakage 3 Compressor Discharge and Air Dryer Inlet Temperature 4 Governor Malfunction 5 Governor Control Line 6 Compressor Unloader BASIC Test Information INDEX Symptom Coolant Compressor leaks coolant 17 0 Engine Oil consumption 6 0 Oil Oil Test Card results 1 0 Oil is present On the outside of the compressor 2 0 17 At the air dryer purge exhaust or Surrounding area 3 0 In the supply reservoir 4 0 At the valves 5 0 At air dryer cartridge 7 0 In the ping tank or compressor discharge aftercooler 8 0 Maintenance amp Usage Guidelines Maintenance Schedule and Usage Guidelines Table A 15 This guide is only for vehicles that use desiccant air dryers Page Number 13 Introduction to the Air Brake Charging System Powered by the vehicle engine the air compressor builds the air pressure for the air brake system The air compressor is typically cooled by the engine coolant system and lubricated by the engine oil supply The compressor s unloader mechanism and governor along with a synchro valve for the Bendix DuraFlo 596 air compressor control the brake system air pressure between a preset maximum and minimum pressure level by monitoring the pressure in the service or supply reservoir When the air pressure becomes greater than th
5. cavities and all the rust and scale from the cooling cavities of the cylinder head body Scrape all the foreign matter from the body surfaces and use shop air pressure to blow the dirt particles from all the cavities Crankcase Clean the carbon and dirt from the inlet and unloader passages Use shop air pressure to blow the carbon and dirt deposits from the unloader passages Oil Passages Thoroughly clean all oil passages through the crankshaft crankcase end covers and base plate or base adapter Inspect the passages with a wire to be sure Blow the loosened foreign matter out with air pressure OIL PASSING All reciprocating compressors currently manufactured will pass a minimal amount of oil Air dryers will remove the majority of oil prior to entrance into the air brake system For particularly oil sensitive systems the Bendix PuraGuard QC oil coalescing filter can be used in conjunction with a Bendix air dryer If compressor oil passing is suspected refer to the TROUBLESHOOTING section and TABLE A for the symptoms and corrective action to be taken In addition Bendix has developed the Bendix Air System Inspection Cup or BASIC test to help substantiate suspected excessive oil passing The steps to be followed when using the BASIC test are presented in APPENDIX A at the end of the TROUBLESHOOTING section INSPECTION OF PARTS Cylinder Head Body Inspect the cylinder head for cracks or damage Apply shop air press
6. information on how to help prevent discharge line freeze ups see Bendix Bulletins TCH 08 21 and TCH 08 22 Appendix B Shorter discharge line lengths or insulation may be required in cold climates Check compressor air inlet line for restrictions brittleness soft or sagging hose conditions etc Repair as necessary Refer to vehicle manufacturer s guidelines for inlet line size Check the engine air filter and service if necessary if possible check the air filter usage indicator Check for leaking damaged or defective compressor air inlet components e g induction line fittings gaskets filter bodies etc Repair inlet components as needed Note Dirt ingestion will damage compressor and is not covered under warranty Replace the compressor only after making certain that none of the preceding conditions 9 0 a through 9 0 h exist Symptom What it may indicate 10 0 Air charging a Governor malfunction system doesn t build air b Restricted discharge line c Air dryer heater malfunction exhaust port frozen open d Compressor malfunction Note For the Bendix DuraFlo 596 air compressor not only the governor but also the SV 1 synchro valve used would need to be tested See Bulletin TCH 001 048 11 0 Compressor a Restricted discharge line safety valve releases air 2 Check Compressor builds too much air Damaged discharge line shown 0 Downstream air brake
7. into the system wash lubricants out of valves collect in brake chambers and valves and can cause malfunction Loss of lubricant can affect valve operating characteristics accelerate wear and cause premature replacement 3 Do not park a vehicle outside after thawing its air system indoors Condensation will form in the system and freeze again Place the vehicle in operation when it is removed to the outdoors Supporting Air and Electrical Lines Make certain tie wraps are replaced and support brackets are re assembled if removed during routine maintenance These items prevent the weight of ice and snow accumulations from breaking or disconnecting air lines and wires Automatic Drain Valves System without Air Dryer As we stated last year routine reservoir draining is the most basic step although not completely effective in reducing the possibility of freeze up While automatic drain valves relieve the operator of draining reservoirs on a daily basis these valves MUST be routinely checked for proper operation Don t overlook them until they fail and a road call is required 35 36 BW1421 2004 Bendix Commercial Vehicle Systems LLC All rights reserved 9 2004 Printed in U S A
8. or carbon blockage and or could indicate a defective or missing safety valve Find blockage go to 9 0 f for details and then replace the compressor Do not re use the safety valve without testing See Symptom 12 0 a 21 22 Symptom What it may indicate 9 0 Air brake f Restricted discharge line charging system seems slow to Check build pressure continued Dash gauges Kinked discharge line shown g Restricted air inlet not enough air to compressor 2 Check Partly collapsed l l l inlet line shown h Poorly filtered inlet air poor air quality to compressor Check i Compressor malfunction Check What you should do If discharge line is restricted gt By more than 1 16 carbon build up replace the discharge line see Table A column 2 on page 15 for recommended size and go to Test 3 on page 26 gt By other restrictions e g kinks Replace the discharge line See Table A column 2 on page 15 for recommended size Retest for air build Return vehicle to service or if problem persists go to 9 0 a The discharge line must maintain a constant slope down from the compressor to the air dryer inlet fitting to avoid low points where ice may form and block the flow If instead ice blockages occur at the air dryer inlet insulation may be added here or if the inlet fitting is a typical 90 degree fitting it may be changed to a straight or 45 degree fitting For more
9. reservoirs see Fig 5 As the piston reaches the top of its stroke and starts down the discharge valve spring and air pressure in the discharge line returns the discharge valve to its seat This prevents the compressed air in the discharge line from returning to the cylinder bore as the intake and compression cycle is repeated Non Compression of Air Unloaded When air pressure in the reservoir reaches the cut out setting of the governor the governor allows air to pass from the reservoir into the cavity beneath the unloader pistons This lifts the unloader pistons and plungers The plungers move up and hold the inlet valves off their seats see Fig 6 With the inlet valves held off their seats by the unloader pistons and plungers air is pumped back and forth between the two cylinders When air is used from the reservoir and the pressure drops to the cut in setting of the governor the governor closes and exhausts the air from beneath the unloader pistons The unloader saddle spring forces the saddle pistons and plungers down and the inlet valves return to their seats Compression is then resumed Discharge Optional Ping Tank Line NN x E Air Dryer oa Compressor Governor Governor plus Synchro valve for the Bendix DuraFlo 596 Compressor FIGURE 3A SYSTEM DRAWING COMPRESSOR amp THE AIR BRAKE SYSTEM GENERAL The compressor is part of the total air brake system more specifically the charging po
10. service Days Since La raining 130 35 40 45 50 55 The Technician looks for the point where the number SENEN stAir Tan O of days since the air tanks were drained meets the wills oll level If itis at or below the low or high use Sixty days since last air Decision point acceptance line the vehicle has passed the test If tank draining the point is above the line we go to the leakage test Air leakage is the number one pt of compressors having STEP D Air Brake System Leakage Test Sone we amen air in turn run too hot and Park the vehicle on level ground and chock wheels Build system pressure to governor cut out pass oil vapor along into the and allow the pressure to stabilize for one minute system Here the Technician 1 Observe the dash gauges for two additional minutes without the service brakes applied conducts a four minute test to 2 Apply service brakes for two minutes allow pressure to stabilize and observe the dash see if leakage is a problem Jangen with the vehicle being tested If you see any noticeable decrease of the dash air gauge readings repair leaks Repeat this test to confirm that air leaks have been repaired and return vehicle to service Please repeat BASIC test at next service interval Note Air leaks can also be found in the charging system parking brakes and or other components inspect and repair as necessary If no air leakage was detected and if you are conducting t
11. service failure of the compressor will occur if gaskets are used in disregard of the preceding If the compressor uses a ball type main bearing press the ball bearing onto the correct end of the crankshaft Position the ball bearing and the crankshaft in the crankcase making sure the drive end of the crankshaft is positioned in the crankcase as marked before disassembly Carefully press the crankshaft and ball bearing into the crankcase using an arbor press In the case of compressors with a front ball bearing place two small seal rings in the counter sunk holes at the front of the crankcase as well as an end cover gasket Install the front end cover in the proper position as marked before disassembly taking care not to damage the new oil seal In the case of compressors with a rear ball bearing place two small seal rings in the counter bore at the rear of the crankcase In one case a gasket is used and in another a large o ring is placed in the counterbore at the rear of the crankcase These are in addition to the seal rings Install the rear end cover in the proper position as marked before disassembly Since June 1978 the two small seal rings have been increased slightly in cross section and a retaining ring added as shown in Figure 15 SEAL RING SEAL RING O RING RETAINER FIGURE 15 In the case of compressors with a sleeve bearing either front or rear place the two small seal rings in the counter sunk holes in the
12. suggestions for making cold weather vehicle operation just a little more bearable Thawing Frozen Air Lines The old saying Prevention is the best medicine truly applies here Each year this activity accounts for an untold amount of unnecessary labor and component replacement Here are some Do s and Don ts for prevention and thawing Do s 1 Do maintain freeze prevention devices to prevent road calls Don t let evaporators or injectors run out of methanol alcohol or protection will be degraded Check the air dryer for proper operation and change the desiccant when needed 2 Do thaw out frozen air lines and valves by placing the vehicle in a warmed building This is the only method for thawing that will not cause damage to the air system or its components 3 Do use dummy hose couplings on the tractor and trailer 4 Do check for sections of air line that could form water traps Look for drooping lines Don ts 1 Do not apply an open flame to air lines and valves Beyond causing damage to the internal nonmetallic parts of valves and melting or burning non metallic air lines WARNING THIS PRACTICE IS UNSAFE AND CAN RESULT IN VEHICLE FIRE 2 Do not introduce pour fluids into air brake lines or hose couplings glad hands Some fluids used can cause immediate and severe damage to rubber components Even methanol alcohol which is used in Alcohol Evaporators and Injectors should not be poured into air lines Fluids poured
13. system check valves or lines may be blocked or damaged c Air dryer lines incorrectly installed d Compressor safety valve malfunction e Compressor unloader mechanism malfunction f Governor malfunction What you should do gt Go to Test 4 on page 27 gt See 9 0 f gt Replace air dryer heater gt Replace the compressor only after making certain the preceding conditions do not exist If discharge line is restricted gt By more than 1 16 carbon build up replace the discharge line see Table A column 2 on page 15 for recommended size and go to Test 3 on page 26 gt By other restrictions e g kinks Replace the discharge line See Table A column 2 on page 15 for recommended size gt The discharge line must maintain a constant slope down from the compressor to the air dryer inlet fitting to avoid low points where ice may form and block the flow If instead ice blockages occur at the air dryer inlet insulation may be added here or if the inlet fitting is a typical 90 degree fitting it may be changed to a Straight or 45 degree fitting For more information on how to help prevent discharge line freeze ups see Bendix Bulletins TCH 08 21 and TCH 08 22 Appendix B Shorter discharge line lengths or insulation may be required in cold climates gt Inspect air lines and verify check valves are operating properly gt Ensure discharge line is installed into the inlet of
14. test should be the definitive method for judging excessive oil fouling oil passing See Appendix A on Bendix page 29 for a flowchart and expanded BASIC Test explanation of the checklist used when conducting the BASIC test Symptom 2 0 Oil on the What it may indicate Engine and or other accessories What you should do Find the source and repair Return the vehicle Outside of the Compressor 2 1 Oil leaking at compressor engine connections 2 2 Oil leaking from compressor 3 0 Oil at air dryer gt Air dryers remove water and oil from the purge exhaust or surrounding area leaking onto compressor a Leak at the front or rear fuel pump etc mounting flange o Leak at air inlet fitting c Leak at air discharge fitting d Loose broken oil line fittings a Excessive leak at head gasket o Leak at bottom cover plate c _Leak at internal rear flange gasket d Leak through crankcase e If unable to tell source of leak Head gasket and rear flange gasket locations Air brake charging system functioning normally 7 Normal to service gt Repair or replace as necessary If the mounting bolt torques are low replace the gasket gt Replace the fitting gasket Inspect inlet hose and replace as necessary gt Replace gasket or fitting as necessary to ensure good seal gt Inspect and repair as necessary gt Go to Test 1 on page 26 gt Re
15. the air dryer and delivery is routed to the service reservoir gt Verify relief pressure is 250 psi Replace if defective gt Go to Test 6 on page 27 gt Go to Test 4 on page 27 23 24 Symptom 12 0 Air dryer safety valve releases air Air dryer safety valve governor 13 0 Reservoir safety valve releases air 14 0 Air dryer doesn t purge Never hear exhaust from air dryer 15 0 Compressor constantly cycles compressor remains unloaded for a very short time What it may indicate a Restriction between air dryer and reservoir b Air dryer safety valve malfunction c Air dryer maintenance not performed d Air dryer malfunction e lmproper governor control line installation to the reservoir f Governor malfunction a Reservoir safety valve malfunction b Governor malfunction c Compressor unloader mechanism malfunction a Air dryer malfunction b Governor malfunction c Air brake system leakage d I mproper governor control line installation to the reservoir a Air brake charging system maintenance not performed Check 6 Compressor unloader mechanism malfunction c Air dryer purge valve or delivery check valve malfunction d Air brake system leakage What you should do gt Inspect delivery lines to reservoir for restrictions and repair as needed Verify relief pressure is at vehicle or component manufactur
16. the proper supply of oil and just as important that the oil is returning to the engine Check the coolant lines to and from the compressor and see that the cooling fins on the crankcase are not clogged with dirt grease etc Check the unloader mechanism for proper and prompt operation Operating Tests Vehicles manufactured after the effective date of FMVSS 121 with the minimum required reservoir volume must have a compressor capable of raising air system pressure from 85 100 P S I in 25 seconds or less This test is performed with the engine operating at maximum governed speed The vehicle manufacturer must certify this performance on new vehicles with appropriate allowances for air systems with greater than the minimum required reservoir volume Air Leakage Tests Leakage past the discharge valves can be detected by removing the discharge line applying shop air back through the discharge port and listening for escaping air Also the discharge valves and the unloader pistons can be checked for leakage by building up the air system until the governor cuts out then stopping the engine With the engine stopped listen for escaping air at the compressor intake To pinpoint leakage if noted apply a small quantity of oil around the unloader pistons If there is no noticeable leakage at the unloader pistons the discharge valves may be leaking If the compressor does not function as described above or leakage Is excessive it is recommend
17. times 1 Park the vehicle on a level surface apply the parking brakes and always block the wheels Always wear safety glasses Stop the engine and remove ignition key when working under or around the vehicle When working in the engine compartment the engine should be shut off and the ignition key should be removed Where circumstances require that the engine be in operation EXTREME CAUTION should be used to prevent personal injury resulting from contact with moving rotating leaking heated or electrically charged componenis Do not attempt to install remove disassemble or assemble a component until you have read and thoroughly understand the recommended procedures Use only the proper tools and observe all precautions pertaining to use of those tools If the work is being performed on the vehicle s air brake system or any auxiliary pressurized air systems make certain to drain the air pressure from all reservoirs before beginning ANY work on the vehicle If the vehicle is equipped with an AD IS air dryer system or a dryer reservoir module be sure to drain the purge reservoir Symptom What it may indicate 1 0 Oil Test Card Not a valid test Look for Y Normal Normal Charging system is working within normal range Check Check Charging system needs further investigation Following the vehicle manufacturer s recommended procedures deactivate the electrical system in a manner that safely removes
18. 00 247 2725 and speak with our Tech Team over Compressor is running hot 360 F Check coolant 4 f and or Discharge Line discharge line 4 g 26 Tests continued Test 4 Governor Malfunction Inspect control lines to and from the governor for restrictions e g collapsed or kinked Repair as necessary Using a calibrated external gauge in the supply Test 5 Governor Control Line 1 Ensure that the governor control line from the reservoir is located at or near the top of the reservoir This line if located near the bottom of the reservoir can become blocked or restricted by the reservoir contents e g water or Ice Test 6 Compressor Unloader Leakage Bendix Compressors Park vehicle chock wheels and follow all standard safety procedures Remove the governor and install a fitting to the unloader port Add a section of air hose min 1ft long for a 1 2 diameter line and a gauge to the fitting followed by a shut off valve and an air source shop air or small air tank Open the shut reservoir service reservoir or reservoir port of the D 2 governor verify cut in and cut out pressures are within vehicle OEM specification If the governor is malfunctioning replace it Perform proper reservoir drain intervals and air dryer cartridge maintenance per Maintenance Schedule and Usage Guidelines Table A on page 15 Return the vehicle to service off and charge the unloader port by allowing air pr
19. 5 Following the vehicle manufacturer s recommended procedures deactivate the electrical system inamanner that safely removes all electrical power from the vehicle 11 10 11 12 Never exceed manufacturers recommended pressures Never connect or disconnect a hose or line containing pressure it may whip Never remove a component or plug unless you are certain all system pressure has been depleted Use only genuine Bendix replacement parts components and kits Replacement hardware tubing hose fittings etc must be of equivalent size type and strength as original equipment and be designed specifically for such applications and systems Components with stripped threads or damaged parts should be replaced rather than repaired Do not attempt repairs requiring machining or welding unless specifically stated and approved by the vehicle and component manufacturer Prior to returning the vehicle to service make certain all components and systems are restored to their proper operating condition For vehicles with Antilock Traction Control ATC the ATC function must be disabled ATC indicator lamp should be ON priorto performing any vehicle maintenance where one or more wheels on a drive axle are lifted off the ground and moving TABULATED DATA Number of cylinders Bore size Stroke Piston displacement at 1250 RPM Piston displacement per revolution Maximum recommended RPM naturally aspirated Minimum coola
20. IR BRAKE 1 800 247 2725 and speak to a Tech Team member 19 20 Symptom 4 0 Oil in Supply or Service Reservoir air dryer installed continued Crankcase Flooding Consider installing a compressor bottom drain kit where available in cases of chronic oil passing What it may indicate Other cont i Poorly filtered inlet air quality to compressor ah ees 4 i j l poor air Inspect the engine air cleaner j Governor malfunction or setting k Compressor malfunction where all other operating conditions have been investigated Bendix compressors are designed to have a dry sump and the presence of excess oil in the crankcase can lead to oil carryover What you should do gt Check for leaking damaged or defective compressor air inlet components e g induction line fittings gaskets filter bodies etc Repair inlet components as needed Note Dirt ingestion will damage compressor and is not covered under warranty D Check Go to Test 4 on page 27 If you found excessive oil present in the service reservoir in step 4 0 b above and you did not find any issues in steps 4 0 c through 4 0 j above the compressor may be passing oil Replace compressor If still under warranty follow normal warranty process Note After replacing a compressor residual oil may take a considerable period of time to be flushed from the air brake system If a maintained Bend
21. If the inlet valve seats are worn or damaged so they cannot be reclaimed by facing they should be replaced Cylinder bores should be checked with inside micrometers or calipers Fig 11 Cylinder bores which are scored or out of round by more than 001 in or tapered more than 002 in should be rebored or honed oversize Oversized pistons and piston rings are available in 010 in 020 in and 030 in oversizes Cylinder bores must be smooth straight and round Clearance between the cast iron pistons and cylinder bores should be between 002 in minimum and 004 in maximum PISTON RING OIL RING PISTON RING CORRECT GAP CLEARANCE WITH RINGS IN CYLINDER ASNE 002 010 FIGURE 12 CORRECT GROOVE CLEARANCE Pistons Check the pistons for scores cracks or enlarged ring grooves replace the pistons if any of these conditions are found Measure each piston with a micrometer in relation to the cylinder bore diameter to be sure the diametral clearance is between 002 in minimum and 004 in maximum Check the fit of the wrist pins to the pistons and connecting rod bushings The wrist pin should be a light press fit in the piston If the wrist pin is a loose fit the piston and pin assembly should be replaced Check the fit of the wrist pin in the connecting rod bushing by rocking the piston This clearance should not exceed 0007 in Replace the wrist pin bushings if excessive clearance is found Wrist pin bushings shoul
22. Step 2 Apply the service brakes and allow the parking brakes and or other components inspect pressure to stabilize Continue holding for two and repair as necessary minutes you may use a block of wood to hold the Test 3 Air Compressor Discharge Temperature and Air Dryer Inlet Note that only vehicles that have passed Test 2 Temperature would be candidates for this test Caution The temperatures used in this test _ Then while maintaining max rpm and are not normal vehicle conditions pressure range measure and record the Above normal temperatures can cause oil as surface temperature of the fittings vapor to pass through the air dryer into the gt at the compressor discharge port T1 air brake system at the air dryer inlet fitting T2 If available a dyno may be used l 5 See table below 1 Allow the compressor to build the air system 6 Retest before returning the vehicle to service pressure to governor cut in 2 Pump the brakes to bring the dash gauge T1 T2 pressure to 90 psi i 3 Allow the compressor to build pressure from eed ad 95 to 105 psi gauge pressure and maintain Fitting Fitting this pressure range by cycling the brakes for under under Temperatures are within five 5 minutes 360 F 200 normal range for this test check other symptoms Go to 4 0 h under over This could indicate a discharge 360 F 200 F line problem e g restriction Call 1 800 AIR BRAKE 1 8
23. affle and remove the cover Replace the pleated paper filter and remount the cleaned cover making sure the filter is in position Be sure to replace the air strainer gasket if the entire air strainer is removed from the compressor intake NOTE Some compressors are fitted with compressor intake adapters which allow the compressor intake to be connected to the engine air cleaner In this case the compressor receives a supply of clean air from the engine air cleaner When the engine air filter is changed the compressor intake adapter should be checked If it is loose remove the intake adapter clean the strainer plate if applicable and replace the intake adapter gasket and reinstall the adapter securely Check line connections both at the compressor intake adapter and at the engine air cleaner Inspect the connecting line for ruptures and replace it if necessary EVERY 6 MONTHS 1800 OPERATING HOURS OR AFTER EACH 50 000 MILES Remove the discharge head fittings and inspect the compressor discharge port and discharge line for excessive carbon deposits If excessive buildup is noted in either the discharge line must be cleaned or replaced and the compressor checked more thoroughly paying special attention to the air induction system oil Supply and return system and proper cooling If necessary repair or replace the compressor Check for proper belt and pulley alignment and belt tension Adjust if necessary paying special attention
24. all electrical power from the vehicle Never exceed manufacturer s recommended pressures Never connect or disconnect a hose or line containing pressure it may whip Never remove a component or plug unless you are certain all system pressure has been depleted Use only genuine Bendix replacement parts components and kits Replacement hardware tubing hose fittings etc must be of equivalent size type and strength as original equipment and be designed specifically for such applications and systems Components with stripped threads or damaged parts should be replaced rather than repaired Do not attempt repairs requiring machining or welding unless specifically stated and approved by the vehicle and component manufacturer Prior to returning the vehicle to service make certain all components and systems are restored to their proper operating condition For vehicles with Antilock Traction Control ATC the ATC function must be disabled ATC indicator lamp should be ON prior to performing any vehicle maintenance where one or more wheels on a drive axle are lifted off the ground and moving What you should do Discontinue using this test Results Do not use this card test to diagnose compressor oil passing issues They are subjective and error prone Use only the Bendix Air System Inspection Cup BASIC test and the methods described in this guide for advanced troubleshooting The Bendix BASIC
25. almost all of the remaining water vapor The compressed air is then passed to the air brake service Supply reservoir The oil droplets and the water collected are automatically purged when the governor reaches its cut out setting For vehicles with accessories that are sensitive to small amounts of oil we recommend installation of a Bendix PuraGuard QC oil coalescing filter designed to minimize the amount of oil present Lubrication Since all Tu Flo 501 compressors are connected to the engine s pressurized oil system a continuous flow of oil is provided to the compressor which is eventually returned to the engine Oil is fed into the compressor in various ways for example through the rear end cover the drive end of the crankshaft or through the front flange adapter An oil passage in the crankshaft conducts pressurized oil to the precision sleeve main bearings and to the connecting rod bearings Splash lubrication of the cylinder bores connecting rod wrist pin bushings and the ball type main bearings on some models is obtained as oil is forced out around the crankshaft journals by engine oil pressure Check the exterior of the compressor for the presence of oil seepage and refer to the TROUBLESHOOTING section for appropriate tests and corrective action Cooling Air flowing through the engine compartment from the action of the engine s fan and the movement of the vehicle assists in cooling the crankcase Coolan
26. arings Damage of this from leaking turbocharger seals can enter kind may not be detected and could lead the air compressor intake and give to compressor problems at a later date misleading symptoms Tests Test 1 Excessive Oil Leakage at the Head Gasket Exterior leaks at the head gasket are not a sign that oil is being passed into the air charging system Oil weepage at the head gasket does not prevent the compressor from building air 2 OO ge ed OO e LOOK Observe the amount of weepage from the head gasket Sj FOR If the oil is only around the cylinder head area it is acceptable return the NSA weepace vehicle to service but if the oil weepage extends down to the nameplate area ERS of the compressor the gasket can be replaced Test 2 Air Brake System and Accessory Leakage Inspect for air leaks when working onavehicle and pedal in position Observe the dash gauges repair them promptly lf you see any noticeable decrease of the dash air Park the vehicle on level ground and chock wheels gauge readings i e more than 4 psi plus two psi Build system pressure to governor cut out and allow for each additional trailer during either two minute the pressure to stabilize for one minute test repair the leaks and repeat this test to confirm Step 1 Observe the dash gauges for two additional that they have been repaired minutes without the service brakes applied Air leaks can also be found in the charging system
27. at of the preset cut out the governor controls the unloader mechanism of the compressor to stop the compressor from building air and also causes the air dryer to purge As the service reservoir air pressure drops to the cut in setting of the governor the governor returns the compressor back to building air and the air dryer to air drying mode As the atmospheric air is compressed all the water vapor originally in the air is carried along into the air system as well as a small amount of the lubricating oil as vapor The duty cycle is the ratio of time the compressor spends building air to the total engine running time Air compressors are designed to build air run loaded up to 25 of the time Higher duty cycles cause conditions that affect air brake charging system performance which may require additional maintenance Factors that add to the duty cycle are air Suspension additional air accessories use of an undersized compressor frequent stops excessive leakage from fittings connections lines chambers or valves etc The discharge line allows the air water vapor and oil vapor mixture to cool between the compressor and air dryer The typical size of a vehicle s discharge line see column 2 of Table A on page 15 assumes a compressor with a normal less than 25 duty cycle operating in a temperate climate See Bendix and or other air dryer manufacturer guidelines as needed When the temperature of the com
28. crankcase Caution An end cover gasket must not be used Place the o ring seal in the groove around the flange adapter or the end cover and affix the thrust washer Install the flange adapter or end cover in the proper position as marked before disassembly taking care not to damage the sleeve bearing 10 Secure the flange adapter front or rear end cover to the crankcase by tightening the four cap screws See note below for torque Note For cast iron flange adapters torque the four 7 16 in cap screws to 38 45 foot pounds For die cast aluminum end covers torque the four 7 16 in cap screws to 25 30 foot pounds All end covers using 5 16 in cap screws or stud and nuts are torqued to 15 18 foot pounds For through drive compressors with a cast iron end cover torque the four 7 16 in cap screws to 25 30 foot pounds Pistons and Connecting Rods If new wrist pin bushings are to be used they should be pressed into the connecting rods so that the oil hole in the bushing lines up with the one in the rod The new bushings should then be reamed or honed to provide between 0001 in 00254 mm and 0006 in 01524 mm clearance on the wrist pin Position the connecting rod in the piston and press in the wrist pin Pistons installed in compressors manufactured prior to November 1976 will have the wrist pin secured in the piston by a lock wire extending through matching holes in wrist pin and piston boss anchored in a hole in the sid
29. crankcase Mark the base plate or base adapter in relation to the crankcase A convenient method to indicate the above relationship is to use a metal scribe to mark the parts with numbers or lines Do not use a marking method that can be wiped off or obliterated during rebuilding such as chalk Remove all compressor attachments such as governors air strainers or inlet fittings discharge fittings and pipe plugs Cylinder Head Remove the six cylinder head cap screws and tap the head with a soft mallet to break the gasket seal Remove the inlet valve springs from the head and inlet valves from their guides in the crankcase Remove inlet valve guides from around the inlet valve seats on the crankcase taking care not to damage seats Scrape off any gasket material from the cylinder head and crankcase Unscrew the discharge valve seats from the head and remove the discharge valves and springs Inspect the discharge valve seats for nicks cracks and excessive wear and replace if necessary The discharge valve stops should be inspected for wear and replaced if excessive peening has occurred To determine if excessive peening has occurred measure the discharge valve travel Discharge valve travel must not exceed 057 inches To remove the discharge valve stops support the machined surface of the cylinder head on an arbor press bed and gently press the stops from the top of the head and out the bottom Be sure to allow sufficient clearance for th
30. d be reamed to between 5314 in and 5317 in after being pressed into the connecting rods Check the fit of the piston rings in the piston ring grooves Check the ring gap with the rings installed in the cylinder bores Refer to Fig 12 for correct gap and groove clearances Crankshaft Check the crankshaft threads keyways tapered ends and all machined and ground surfaces for wear scores or damage Standard crankshaft journals are 1 1250 in to 1 1242 in in diameter If the crankshaft journals are excessively scored or worn or out of round and cannot be reground the crankshaft must be replaced Connecting rod bearing inserts are available in 010 in 020 in and 030 in undersizes for compressors with reground crankshafts Main bearing journals must be maintained so the ball bearings are a snug fit or so that no more than 0065 in clearance exists between the precision sleeve main bearing and the main bearing journals on the crankshaft In crankshafts fitted with oil seal rings the oil seal ring groove or grooves must not be worn The ring groove walls must have a good finish and they must be square Check to be sure the oil passages are open through the crankshaft Connecting Rod Bearings Used bearing inserts must be replaced Connecting rod caps are not interchangeable The locking slots of the connecting rod and cap should be positioned adjacent to each other Clearance between the connecting journal and the connecting rod b
31. e stops between the press bed and the bottom of the cylinder head The valve stop bores in the cylinder head must be inspected for excessive scoring Anew head body must be used if scoring is excessive Discard the inlet valves and springs the discharge valves and springs and the discharge valve seats if defective Crankcase Base Plate or Adapter Remove the cap screws securing the base plate or base adapter Tap with soft mallet to break the gasket seal Scrape off any gasket material from crankcase and plate or adapter Connecting Rod Assemblies Note Before removing the connecting rods mark each connecting rod and its cap Each connecting rod is matched to its own cap for proper bearing fit and these parts must not be interchanged Straighten the prongs of the connecting rod bolt lock strap and remove the bolts and bearing caps Push the piston with the connecting rods attached out the top of the cylinders of the crankcase Replace the bearing caps on their respective connecting rods Remove the piston rings from the pistons If the pistons are to be removed from the connecting rods remove the wrist pin lock wires or teflon plugs and press the wrist pins from the pistons and connecting rods lf the pistons are removed from the rod inspect the bronze wrist pin bushing Press out and replace the bushing if it is excessively worn See inspection of Parts Discard the piston rings and the connecting rod journal bearings Discard
32. e wall of the piston If the original pistons are used the wrist pin must be pressed in so the hole in the wrist pin aligns with that of the piston and secure same by inserting the new lockwire through the hole in piston and wrist pin and lock the wire by snapping the short 90 section into the lockwire hole in the bottom of the piston Compressors built after November 1976 will have the wrist pin secured by Teflon buttons in either end of the wrist pin allowing the wrist pin to float The Teflon buttons pc no 292392 may be used with either new or old wrist pins The later design pistons have two rings above the wrist pin and one below Install the piston rings in the correct location with the ring pipmarks up Stagger the position of the ring gaps Pre lubricate the piston piston rings wrist pins and connecting rod Unloader A new unloader kit should used when rebuilding Figure 14 Piece Number 279615 The unloader pistons in the kit are pre lubricated with a special lubricant piece number 239379 and need no additional lubrication Install the unloader pistons in their bores being careful not to cut the o rings Position the unloader plungers in their guides and slip them in and over the tops of the pistons Install the unloader spring seat in the crankcase inlet cavity a small hole is drilled in the crankcase for this purpose Position the saddle between the unloader piston guides so its forks are centered on the guides Insta
33. earing must not be less than 0009 in or more than 0021 in after rebuilding REPAIRS Discharge Valves Valve Stops and Seats lf the discharge valve seats merely show signs of slight wear they can be dressed by using a lapping stone grinding compound and grinding tool If the discharge valve stops are to be replaced an application of a sealer is required such as Locktite Retaining Compound 75 Be sure that the press fit between the discharge valve stop outside diameter and the valve stop bore in the cylinder head is a minimum of 0008 in and a maximum of 0028 in If this fit can not be maintained a new cylinder head body must be used Be sure to completely support the outside top of the cylinder head casting while pressing in the replacement stops Install the new discharge valve springs and valves Screw in the discharge valve seats Discharge valve travel should be between 041 in to 057 in To test for leakage by the discharge valves apply 100 pounds of air pressure through the cylinder head discharge port and apply a soap solution to the discharge valves and seats A slight leakage in the form of soap bubbles is permissible If excessive leakage is found leave the air pressure applied and with the use of a fibre or hardwood dowel and a hammer tap the discharge valves off their seats several times This will help the valves to seat and should reduce the leakage With the air pressure still applied at the discharge port
34. ect the coolant lines for kinks and restrictions and fittings for restrictions Replace as necessary gt Verify coolant lines go from engine block to compressor and back to the water pump Repair as necessary gt If discharge line is restricted or more than 1 16 carbon build up is found replace the discharge line See Table A column 2 on page 15 for recommended size Replace as necessary gt The discharge line must maintain a constant slope down from the compressor to the air dryer inlet fitting to avoid low points where ice may form and block the flow If instead ice blockages occur at the air dryer inlet insulation may be added here or if the inlet fitting is a typical 90 degree fitting it may be changed to a straight or 45 degree fitting For more information on how to help prevent discharge line freeze ups see Bendix Bulletins TCH 08 21 and TCH 08 22 Appendix B Shorter discharge line lengths or insulation may be required in cold climates gt Check compressor air inlet line for restrictions brittleness soft or sagging hose conditions etc Repair as necessary Inlet line size is 3 4 ID Maximum restriction requirement for compressors is 25 inches of water 5 gt Check the engine air filter and service if necessary if possible check the air filter usage indicator Check If a maintained Bendix PuraGuard system filter or Bendix PuraGuard QC oil coalescing filter is installed call 1 800 A
35. ed oil system to lubricate the internal moving parts A nameplate is attached to the crankcase to identify the compressor The nameplate displays a Bendix piece number or in some cases an engine or vehicle manufacturer s piece number along with a serial number TU FLO 501 MANUFACTURED BY BENDIX FIGURE 2 COMPRESSOR NAMEPLATE OPERATION General The compressor is driven by the vehicle engine and is operating continuously while the engine is running Actual compression of air is controlled by the compressor unloading mechanism and the governor The governor is generally mounted on the compressor and maintains the brake system air pressure to a preset maximum and minimum pressure level Intake and Compression of Air Loaded During the down stroke of the piston a slight vacuum is created between the top of the piston and the head causing the flat circular inlet valve to move up and off its seat Note the flat square discharge valve remains on its seat Atmospheric air is drawn through the air strainer by the 2 open inlet valve and into the cylinder see Fig 4 As the piston begins its upward stroke the air that was drawn into the cylinder on the down stroke is being compressed Air pressure on top of the inlet valve plus the force of its spring returns the inlet valve to its seat The piston continues the upward stroke and compressed air then flows by the open discharge valve into the discharge line and on to the
36. ed compressor frequent stops excessive leakage The Air Brake Charging System supplies the compressed air for the braking system as well as other air accessories for the vehicle The system usually consists of an air compressor governor discharge line air dryer and service reservoir Optional Bendix PuraGuara QC Oil Coalescing Filter Service Reservoir Supply Reservoir Reservoir Drain from fittings connections lines chambers or valves etc Refer to Table Ain the Troubleshooting section for a guide to various duty cycles and the consideration that must be given to maintenance of other componenis COMPRESSOR INSTALLATION While the original compressor installation is usually completed by the vehicle manufacturer conditions of operation and maintenance may require additional consideration The following presents base guidelines DISCHARGE LINE The discharge line allows the air water vapor and oil vapor mixture to cool between the compressor and air dryer or reservoir The typical size of a vehicle s discharge line See column 2 of Table Ain the Troubleshooting section assumes a compressor with a normal less than 25 duty cycle operating in a temperate climate See Bendix and or other air dryer manufacturer guidelines as needed The discharge line must maintain a constant slope down from the compressor to the air dryer inlet fitting or reservoir to avoid low points where ice may form and block the flo
37. ed that it be returned 6 FIGURE 10 TU FLO 501 AIR COMPRESSOR THRU DRIVE EXPLODED VIEW to the nearest authorized Bendix Distributor for a factory remanufactured compressor If this is not possible the compressor can be repaired using genuine Bendix replacement parts in which case the following information should prove helpful REMOVING AND DISASSEMBLY Removing These instructions are general and are intended to be a guide in some cases additional preparations and precautions are necessary Chock the wheels of the vehicle and drain the air pressure from all the reservoirs in the system Drain the engine cooling system and the cylinder head of the compressor Disconnect all air water and oil lines leading to and from the compressor Remove the drive gear s or pulley from the compressor crankshaft using a gear puller Inspect the pulley or gear and associated parts for visible wear or damage Since these parts are precision fitted they must be replaced if they are worn or damaged DISASSEMBLY General Remove road dirt and grease from the exterior of the compressor with a cleaning solvent Before the compressor is disassembled the following items should be marked to show their relationship when the compressor is assembled Mark both the front and rear end cover in relation to the crankcase Mark the drive end of the crankshaft in relation to the front end cover and the crankcase Mark the cylinder head in relation to the
38. er specifications Replace if defective See Maintenance Schedule and Usage Guidelines Table A column 3 on page 15 Verify operation of air dryer Follow vehicle O E maintenance recommendations and component Service Data information Go to Test 5 on page 27 Go to Test 4 on page 27 Verify relief pressure is at vehicle or component manufacturer s specifications typically 150 psi Replace if defective Go to Test 4 on page 27 Go to Test 6 on page 27 Verify operation of air dryer Follow vehicle O E maintenance recommendations Go to Test 4 on page 27 Go to Test 2 on page 26 Go to Test 5 on page 27 Available reservoir capacity may be reduced by build up of water etc Drain and perform routine maintenance per Table A columns 3 amp 4 on page 15 Go to Test 6 on page 27 Verify operation of air dryer Follow vehicle O E maintenance recommendations and component Service Data information Go to Test 2 on page 26 Symptom What it may indicate What you should do 16 0 Compressor a Compressor leaks air at Check for leaking damaged or defective leaks air connections or ports compressor fittings gaskets etc Repair or replace as necessary 6 Compressor unloader mechanism Go to Test 6 on page 27 malfunction c Damaged compressor head gt Anairleak at the head gasket may indicate gasket a downstream restriction such as a freeze up or carbon blockage and or could Testing for lea
39. esent The Air Brake Charging System supplies the compressed air for the braking system as well as other Discharge Optional Ping Tank air accessories for the vehicle The system usually consists of an air compressor governor discharge line Line oN Air Dryer air dryer and service reservoir x Compressor Governor Governor plus Synchro valve for the Bendix DuraFlo 596 Compressor 14 Optional Bendix PuraGuard System Filter or PuraGuara QC Oil Coalescing Filter Service Reservoir Supply Reservoir Reservoir Drain Table A Maintenance Schedule and Usage Guidelines Regularly scheduled maintenance is the single most important factor in maintaining the air brake charging system Recom Recom Acceptable Typical Discharge mended mended Reservoir i Air Dryer Reservoir Oil Contents H No of Cartridge Drain at Regular Vehicle Used for Axles Replacement Schedule Drain Interval Low Air Use j fo a with less than 15 duty BASIC test e g Line haul single trailer Ole cay oven ACCEpIAD S w o air suspension air over parades Recom range a a brakes less 3 mended 3 oil units 5 8 in 9ft er month aa a Every 3 Every p Years Month eo Max of appendix e g ee haul single trailer every 90 A with air Suspension school bus a Lay High Air Use Compressor with up to 25 duty cycle e g Double triple trailer open highway coach RV most pick up am
40. essor discharge port without forming water traps kinks or restrictions Cross overs from one side of the frame rail to the other if required should occur as close as possible to the compressor Fitting extensions must be avoided Recommended discharge line lengths and inside diameters are dependent on the vehicle application and are as follows Typical P amp D School Bus and Line Haul The maximum discharge line length is 16 feet Length I D Min Other Requirements 6 0 9 5 ft Yo in None 9 5 12 ft Yo in Last 3 feet including fitting at the end of the discharge line must be insulated with 1 2 inch thick closed cell polyethylene pipe insulation 12 16 ft 5 8 in Last 3 feet including fitting at the end of the discharge line must be insulated with 1 2 inch thick closed cell polyethylene pipe insulation If the discharge line length must be less than 6 feet or greater than 16 feet contact your local Bendix representative 32 Appendix B Continued Bulletin No TCH 008 021 Effective Date 11 1 92 Page 2 of 2 High Duty Cycle Vehicles City Transit Coaches Refuse Haulers Etc The maximum discharge line length is 16 feet Length I D min Other Requirements 10 16 ft Yo in None lf the discharge line length must be less than 10 feet or greater than 16 feet contact your local Bendix representative System Leakage Check the air brake system for excessive air leakage using the Bendix Dual System Air Brake Test
41. essure to enter the hose and unload the compressor Shut off the air supply and observe the gauge Asteady reading indicates no leakage at the unloader port but a falling reading shows that the unloader mechanism is leaking and needs to be serviced 27 28 NOTES Test for air leakage Appendix A Information about the BASIC Test kit Bendix P N 5013711 Service writer records info including the number of days since all air tanks were drained and fills out symptom checklist Technician inspects items START BASIC TEST Park vehicle on LEVEL ground Chock wheels drain air from system Drain contents of ALL air tanks into BASIC cup Is there YES lt 1 less than one unit of liquid NO Is there more than one unit of YES H O e water or e cloudy emulsion mixture NO only oil Is this a transit vehicle bulk unloader or has more than 5 axles YES this is a high air use vehicle NO this is a low air use vehicle Find the point on the label where the number of oil units meets the number of days ERCE the vehicle s air tanks were last drained were last drained Is the point above the HIGH Air Use line on the Is the point above the LOW Air Use line on the cup Use Test 2 Air Leakage JU Vehicle OK service Repair leaks and return vehicle to service the vehicle have excessive air lea
42. est now and return the vehicle to service Vehicle passes 4 Q more than one oil unit of water or a cloudy emulsion mixture is found a Change the vehicle s air dryer cartridge see Footnote 1 b Conduct the 4 minute leakage test Step D c STOP the inspection and check the vehicle again after 30 days see Footnote 2 D CHI go to Step C Footnote 1 Note Typical air dryer cartridge replacement schedule is every 3 yrs 300K miles for low air use vehicles and every year 100K miles for high air use vehicles Footnote 2 To get an accurate reading for the amount of oil collected during a 30 day period ask the customer not to drain the air tanks before returning Note that 30 90 days is the recommended air tank drain schedule for vehicles equipped with a Bendix air dryer that are properly maintained If in cold weather conditions the 30 day air tank drain schedule is longer than the customer s usual E the customer must determine based on its experience with the vehicle whether to participate now or wait for warmer weather See the cold weather tips in Bulletins TCH 008 21 and TCH 008 22 included in Appendix B of the advanced troubleshooting guide contents of all the air tanks on the vehicle should be used Note for returning vehicles that are being retested after a water cloudy emulsion mixture was found last time and the air dryer cartridge replaced If more than one oil unit of water or a cloudy emulsion mixture i
43. his test after completing Step C go to Step E na The Technician only reaches ee ee since the air tanks were last drained exceeds the accep tance level AND the vehicle passes the four minute leakage test no noticeable leakage was detected Replace the compressor Note If the compressor is within warranty period please follow standard warranty procedures Attach the completed checklist to warranty claim 31 Appendix B Technical Bulletn Bulletin No TCH 008 021 Effective Date 11 1 92 Page 1 of 2 nadi Subject Air Brake System Cold Weather Operation Tips As the cold weather approaches operators and fleets alike begin to look to their vehicles with an eye toward winterization and particularly what can be done to guard against air system freeze up Here are some basic Tips for operation in the cold weather Engine Idling Avoid idling the engine for long periods of time In addition to the fact that most engine manufacturers warn that long idle times are detrimental to engine life winter idling is a big factor in compressor discharge line freeze up Discharge line freeze ups account for a significant number of compressor failures each year The discharge line recommendations under Discharge Lines are important for all vehicles but are especially so when some periods of extended engine idling can not be avoided Discharge Lines The discharge line should slope downward form the compr
44. ing normally Y Normal a Air brake charging system functioning normally Y Normal b Air brake system leakage c Compressor may be undersized for the application d Compressor unloader mechanism malfunction e Damaged compressor head gasket What you should do gt See engine service manual Check gt Air dryers remove water and oil from the air brake charging system A small amount of oil is normal Check that regular maintenance is being performed and that the amount of oil in the air tanks reservoirs is within the acceptable range shown by the BASIC Test see also column 5 of Table A on page 15 Replace the air dryer cartridge as needed and return the vehicle to service Follow vehicle O E maintenance recommendation for these components Using dash gauges verify that the compressor builds air system pressure from 85 100 psi in 40 seconds or less with engine at full governed rom Return the vehicle to service Go to Test 2 on page 26 See Table A column 1 on page 15 for some typical compressor applications If the compressor is too small for the vehicle s role for example where a vehicle s use has changed then upgrade the compressor Note The costs incurred e g installing a larger capacity compressor etc are not covered under original compressor warranty Go to Test 6 on page 27 An air leak at the head gasket may indicate a downstream restriction such as a freeze up
45. is in use The troubleshooting presented will cover not only the compressor itself but also other charging system devices as they relate to the compressor WARNING PLEASE READ AND FOLLOW THESE INSTRUCTIONS TO AVOID PERSONAL INJURY OR DEATH When working on or around a vehicle the following general precautions should be observed at all times 1 Park the vehicle on a level surface apply the parking brakes and always block the wheels Always wear Safety glasses 2 Stop the engine and remove ignition key when working under or around the vehicle When working in the engine compartment the engine should be shut off and the ignition key should be removed Where circumstances require that the engine be in operation EXTREME CAUTION should be used to prevent personal injury resulting from contact with moving rotating leaking heated or electrically charged components 3 Do not attempt to install remove disassemble or assemble a component until you have read and thoroughly understand the recommended procedures Use only the proper tools and observe all precautions pertaining to use of those tools 4 Ifthe work is being performed on the vehicle s air brake system or any auxiliary pressurized air systems make certain to drain the air pressure from all reservoirs before beginning ANY work on the vehicle If the vehicle is equipped with an AD IS air dryer system ora dryer reservoir module be sure to drain the purge reservoir
46. ix PuraGuard system filter or Bendix PuraGuard QC oil coalescing filter is installed call 1 800 AIR BRAKE 1 800 247 2725 and speak to a Tech Team member 5 0 Oil present at valves e g at exhaust or seen during servicing Air brake system valves are required to tolerate a light coating of oil Normal Genuine Bendix valves are all SAE J2024 compliant gt A small amount of oil does not affect SAE J2024 compliant valves 5 gt Check that regular maintenance is being performed and that the amount of oil in the air tanks reservoirs is within the acceptable range shown on the Bendix BASIC test cup see also column 5 of Table A on page 15 Return the vehicle to service For oil sensitive systems see page 14 SAE J2024 outlines tests all air brake system pneumatic components need to be able to pass including minimum levels of tolerance to contamination Symptom 6 0 Excessive oil consumption in engine 7 0 Oil present at air dryer cartridge during maintenance 8 0 Oil in ping tank or compressor dis charge aftercooler 9 0 Air brake charging system seems slow to build pressure What it may indicate A problem with engine or other engine accessory The engine service manual has more information Air brake charging system is functioning normally Normal Oil shown leaking from an air dryer cartridge Air brake charging system is function
47. kage END TEST NO NO did not know when last drained Re test with the BASIC Test after 30 days the number of days since last END TEST YES number of days was known 30 90 days Replace the Compressor If under warranty follow standard procedures If after a compressor was already replaced the vehicle fails the BASIC test again do not replace the compressor use the Advanced Troubleshooting Guide to investigate the cause s END TEST Return vehicle to Bendix Air System Inspection Cup BASIC Test Information Vehicle OK END TEST Return vehicle to service Cloudy emulsion mixture a Is this vehicle being re tested after water etc was found last time YES NO Find the point on the label where the number of oil units meets the number of days We the vehicle s air tanks Go to the Advanced Troubleshooting QOS Change air dryer cartridge Guide to find reason s for presence of water Test for air leakage Use Test 2 END TEST Re test with the BASIC Test after 30 days END TEST END TEST If the number of days since the air tanks were drained is unknown use the 30 day line Note Typical air dryer cartridge replacement schedule is every 3 yrs 300K miles for low air use vehicles and every year 100K miles for high air use vehicles To get an accurate reading for the amount of oil col
48. ks Head indicate a defective or missing safety with soap solution e gasket valve Find blockage go to 9 0 f for OT D m location details and then replace the compressor Do not re use the safety valve without testing See Symptom 12 0 a 17 0 Compressor a lmproperly installed plugs or Inspect for loose or over torqued fittings leaks coolant coolant line fittings Reseal and tighten loose fittings and plugs as necessary If overtorqued fittings and plugs have cracked ports in the head replace the compressor b Damaged compressor head Anairleak at the head gasket may indicate gasket a downstream restriction such as a freeze up or carbon blockage and or could indicate a defective or missing safety valve Find blockage go to 9 0 f for details and then replace the compressor Do not re use the safety valve without testing See Symptom 12 0 a c Porous compressor head casting If casting porosity is detected replace the compressor 18 0 Noisy a Damaged compressor gt Replace the compressor compressor Multi cylinder compressors only Other Miscellaneous Areas to Consider This guide attempts to cover most e Where a compressor does not have a compressor system problems Here are safety valve installed if a partial or some rare sources of problems not complete discharge line blockage has covered in this guide occurred damage can occur to the e Turbocharger leakage Lubricating oil connecting rod be
49. lected during a 30 day period ask the customer not to drain the air tanks before returning Note that 30 90 days is the recommended air tank drain schedule for vehicles equipped with a Bendix air dryer that are properly maintained If in cold weather conditions the 30 day air tank drain schedule is longer than the customer s usual draining interval the customer must determine based on its experience with the vehicle whether to participate now or wait for warmer weather See the cold weather tips in Bulletins TCH 008 21 and TCH 008 22 included on pages 32 34 of this document Note After replacing a compressor residual oil may take a considerable period of time to be flushed from the air brake system 29 Appendix A continued Information about the BASIC Test kit Bendix P N 5013711 Filling in the Checklist for the Bendix Air System Inspection Cup BASIC Test Note Follow all standard safety precautions For vehicles using a desiccant air dryer The Service Writer fills out these fields with information gained from the customer Vehicle Checklist for Technician Customer s Complaint Have you confirmed complaint Please check all that apply 4 Relay valve 0 leaks oil Q malfunctions The Technician Dash valve 0 leaks oil O malfunctions The Service Writer Q Air dryer leaks oil Ono O yes isn a or also checks off any Q Governor malfunction 2 no O yes anetar complaints thatthe
50. ll the unloader spring making sure it seats over the spring seats both in the crankcase and on the saddle Position and install the inlet valve guides then drop the inlet valves in their guides The inlet valves should be a loose Sliding fit in the guides FIGURE 16 UNLOADER MECHANISM Cylinder Head Install the inlet valve springs in the cylinder head by applying a turning motion to the spring after it is in the head The turning motion should dig the spring wire into the spring seat in the bottom of the spring bore in the head Should this procedure fail after repeated attempts use a very small quantity of grease to hold them in place just enough to keep the springs from failing out Place the cylinder head gasket on the cylinder block Carefully align the cylinder head assembly on the block and install the cap screws tightening them evenly to a torque of 25 30 foot pounds Base Plate or Base Adapter Position the base plate or base adapter gasket on the crankcase and install the base plate or base adapter as marked before disassembly Tighten the six cap screws securing the cast iron base adapter evenly to a torque of 38 45 foot pounds and 12 16 foot pounds for base plate or aluminum cover Testing Rebuilt Compressor In order to properly test a compressor under operating conditions a test rack for correct mounting cooling lubricating and driving the compressor is necessary Such tests are not compulsory if the unit ha
51. nces of alcohol per hour of compressor loaded time compressing air City pick up and delivery vehicles will operate with the compressors loaded compressing air more while compressors on highway vehicles will be loaded less These figures are approximate and assume that air system leakage is within the limits of the Bendix Dual System Air Brake Test and Check List BW1279 Last but not least begin using alcohol several weeks prior to freezing weather to ensure that the system is completely protected Use only methanol alcohol such as Bendix Air Guard in evaporators or injectors Air Dryers Make certain air brake system leakage is within the limits stated in BW1279 Check the operation and function of the air dryer using the appropriate Service Data Sheet for the air dryer AD 9 Air Dryer Service Data Sheet SD 08 2412 AD 4 Air Dryer Service Data Sheet SD 08 2407 AD 2 Air Dryer Service Data Sheet SD 08 2403 AD IP Air Dryer Service Data Sheet SD 08 2414 AD SP Air Dryer Service Data Sheet SD 08 2415 Trailer System Guard Air Dryer Service Data Sheet SD 08 2416 33 34 Appendix B Continued x Bendix Technical Bulletin u Bulletin No TCH 008 022 Effective Date 1 1 1994 Page 1 of 1 Subject Additional Cold Weather Operation Tips for the Air Brake System Last year we published Bulletin PRO 08 21 which provided some guidelines for winterizing a vehicle air brake system Here are some additional
52. not to over tighten the belt tension Check for noisy compressor operation which could indicate a worn drive gear coupling or a loose pulley Adjust and or replace as necessary Check all compressor mounting bolts and retighten evenly if necessary Check for leakage and proper unloader mechanism operation Replace if defective in any way EVERY 24 MONTHS 7200 OPERATING HOURS OR AFTER EACH 200 000 MILES Perform a thorough inspection as indicated below and depending upon the results of this inspection or experience disassemble the compressor clean and inspect all parts thoroughly repair or replace all worn or damaged parts using only genuine Bendix replacements or replace the compressor with a genuine Bendix remanufactured unit IMPORTANT Should it be necessary to drain the engine cooling system to prevent damage from freezing the cylinder head of the compressor must also be drained GENERAL SERVICE CHECKS Inspection It is of the utmost importance that the compressor receives a clean supply of air The air strainer must be properly installed and kept clean Ifthe compressor intake is connected to the engine air cleaner supercharger etc these connections must be properly installed and maintained Check the compressor mountings to be sure they are secure Check the drive for proper alignment belt tension etc Inspect the oil supply and return lines Be sure these lines are properly installed and that the compressor is getting
53. nt flow at maximum RPM Horsepower required at 3000 RPM against 100 PSI head pressure Recommended minimum discharge line size Recommended minimum oil return line size Recommended minimum oil supply line size Recommended minimum unloader line size Recommended minimum inlet cavity line size when compressor is connected to engine air cleaner Recommended minimum coolant line size Recommended maximum inlet air temperature Recommended maximum discharge air temperature Minimum pressure required to unload 2 2 625 in 1 50 in 12 cu ft 16 5 Cu in 3000 2 5 gal min 4 9H P 5 8 in OD Copper Tube 5 8 in OD Tubing 1 4 in OD Tubing 1 4 in OD Tubing 5 8 in ID minimum 1 2 in OD Tubing 250 F 400 F 60 PSI This troubleshooting guide obsoletes and supersedes all previous published troubleshooting information relative to Bendix air compressors Advanced Troubleshooting Guide for Air Brake Compressors The guide consists of an introduction to air brake charging system components a table showing recommended vehicle maintenance schedules and a troubleshooting symptom and remedy section with tests to diagnose most charging system problems Symptom Page Number Air Air brake charging system Slow build 9 0 Doesn t build air 10 0 Air dryer Doesn t purge 14 0 Safety valve releases air 12 0 Compressor Constantly cycles 15 0 Leaks air 16 0 Safety valve releases air 11 0 Noisy
54. nty Note To help prevent discharge line freeze ups shorter discharge line lengths or insulation may be required in cold climates See Bendix Bulletins TCH 08 21 and TCH 08 22 included in Appendix B for more information 5 For certain vehicles applications where turbo charged inlet air is used a smaller size compressor may be permissible Every 2 Years days For the BASIC Test Kit Order Bendix P N 5013711 BASIC test acceptable range Every 5 oil units Month per month See appendix A Note Compressor and or air dryer upgrades are recommended in cases where duty cycle is greater than the normal range for the examples above For Bendix Tu Flo 550 and 750 compressors unloader service is recommended every 250 000 miles 15 Air Brake Charging System Troubleshooting How to use this guide Find the sympton s that you see then move to the right to find the possible causes What it may indicate and remedies What you should do Review the warranty policy before performing any intrusive compressor maintenance Unloader or cylinder head gasket replacement and resealing of the bottom cover plate are usually permitted under warranty Follow all standard safety procedures when performing any maintenance WARNING Please READ and follow these instructions to avoid personal injury or death When working on or around a vehicle the following general precautions should be observed at all
55. of the cylinder head check for leakage around the discharge valve stops exposed on the top of the cylinder head casting No leakage is permitted FIGURE 13 DISCHARGE VALVE VALVE STOP AND SEAT FIGURE 14 INLET VALVE AND SEAT Inlet Valves and Seats Inlet valves and springs should be replaced if the inlet valve seats show signs of slight nicks or scratches They can be redressed with a fine piece of emery cloth or by lapping with a lapping stone grinding compound and grinding tool If the seats are damaged to the extent that they cannot be reclaimed they must be replaced The dimension from the top of the cylinder block to the inlet valve seat should not exceed 113 in nor be less than 101 in ASSEMBLY General Note All torques specified in this manual are assembly torques and can be expected to fall off after assembly is accomplished Do not retorque after initial assembly torques fall To convert inch pounds of torque to foot pounds of torque divide inch pounds by 12 inch pounds 12 foot pounds To convert foot pounds of torque to inch pounds of torque multiply foot pounds by 12 foot pounds x 12 inch pounds Installing the Crankshaft Cautionary Note All flange mounted compressors must be assembled without a gasket between the crankcase and flange adapter and some compressors do not require gaskets on the end cover Install the new crankcase gaskets only where they were removed during disassembly In
56. p delivery yard or terminal jockey off highway construction loggers concrete mixer dump truck fire truck Compressor with up to 25 duty cycle with up to 25 duty cycle ee less Tw Ra Compressor with up to 25 duty cycle e g City transit bus refuse bulk unloaders low boys urban region coach central tire inflation 12 ar Every or oil carry over on control suggested Year less upgrades Footnotes s e 4 2 Q fe S LO N LL 5 F 2S ge aa Bendix BA 921 air compressor Bendix Tu Flo 550 air compressor Bendix BA 922 or DuraFlo 596 air compressor For oil carry over control suggested upgrades 5 8 in 12 ft For oil carry over control suggested upgrades 5 8 in 15 ft 3 4in 15 ft 1 With increased air demand the air dryer cartridge needs to be replaced more often 2 Use the drain valves to slowly drain all reservoirs to zero psi 3 Allow the oil water mixture to fully settle before measuring oil quantity 4 To counter above normal temperatures at the air dryer inlet and resultant oil vapor passing upstream in the air system replace the discharge line with one of a larger diameter and or longer length This helps reduce the air s temperature If sufficient cooling occurs the oil vapor condenses and can be removed by the air dryer Discharge line upgrades are not covered under warra
57. pressed air that enters the air dryer is within the normal range the air dryer can remove most of the charging system oil If the temperature of the compressed air is above the normal range oil as oil vapor is able to pass through the air dryer and into the air system Larger diameter discharge lines and or longer discharge line lengths can help reduce the temperature The discharge line must maintain a constant slope down from the compressor to the air dryer inlet fitting to avoid low points where ice may form and block the flow If instead ice blockages occur at the air dryer inlet insulation may be added here or if the inlet fitting is a typical 90 degree fitting it may be changed to a straight or 45 degree fitting For more information on how to help prevent discharge line freeze ups see Bendix Bulletins TCH 08 21 and TCH 08 22 see pages 32 34 Shorter discharge line lengths or insulation may be required in cold climates The air dryer contains a filter that collects oil droplets and a desiccant bed that removes almost all of the remaining water vapor The compressed air is then passed to the air brake service Supply reservoir The oil droplets and the water collected are automatically purged when the governor reaches its cut out setting For vehicles with accessories that are sensitive to small amounts of oil we recommended installation of a Bendix PuraGuard system filter designed to minimize the amount of oil pr
58. pressor spends building air to total engine running time Air compressors are designed to build air to run loaded up to 25 of the time Higher duty cycles cause conditions that affect air brake charging system performance which may require additional maintenance Factors that add to the duty cycle are air Suspension additional air accessories use of an undersized compressor frequent stops excessive leakage from fittings connections lines chambers or valves etc 18 What you should do gt Drain all air tanks and check vehicle at next service interval using the Bendix BASIC test See Table A on page 15 column 3 and 4 for recommended service schedule Check Drain all air tanks into Bendix BASIC test cup Bendix Air System Inspection Cup If less than one unit of reservoir contents is found the vehicle can be returned to service Note If more than one oil unit of water or a cloudy emulsion mixture is present change the vehicle s air dryer check for air system leakage Test 2 on page 26 stop inspection and check again at the next service interval See the BASIC test kit for full details If less than one oil unit of water or water cloudy emulsion mixture is present use the BASIC cup chart on the label of the cup to determine if the amount of oil found is within the acceptable level gt If within the normal range return the vehicle to service For vehicles with accessories that are sensiti
59. rtion of the air brake system As a component in the overall system its condition duty cycle proper installation and operation will directly affect other components in the system Powered by the vehicle engine the air compressor builds the air pressure for the air brake system The air compressor is typically cooled by the engine coolant system lubricated by the engine oil supply and has its inlet connected to the engine induction system As the atmospheric air is compressed all the water vapor Originally in the air is carried along into the air system as well as a small amount of the lubricating oil as vapor If an air dryer is not used to remove these contaminants prior to entering the air system the majority but not all will condense in the reservoirs The quantity of contaminants that reach the air system depends on several factors including installation maintenance and contaminant handling devices inthe system These contaminants must either be eliminated prior to entering the air system or after they enter DUTY CYCLE The duty cycle is the ratio of time the compressor spends building air to the total engine running time Air compressors are designed to build air run loaded up to 25 of the time Higher duty cycles cause conditions that affect air brake charging system performance which may require additional maintenance Factors that add to the duty cycle are air Suspension additional air accessories use of an undersiz
60. s been carefully rebuilt by an experienced person A compressor efficiency or build up test can be run which is not too difficult An engine lubricated compressor must be connected to an oil supply line of at least 15 P S I pressure during the test and an oil return line must be installed to keep the crankcase drained Connect to the compressor discharge port a reservoir with a volume of 1500 cubic inches including the volume of connecting line With the compressor operating at 2100 R P M the time required to raise the reservoir s pressure from 85 P S I to 100 P S I should not exceed 7 seconds During this test the compressor should be checked for gasket leakage and noisy operation as well as unloader operation and leakage INSPECTION OF REBUILT UNIT Check to be sure that covers plugs or masking tape are used to protect all ports if compressor is not to be installed immediately Fit the end of all crankshafts with keys nuts and cotter pins as required and then protect the ends against damage by wrapping with masking tape or friction tape The open bottom of a vertical engine lubricated compressors should be protected against the entrance of dirt during handling or storage by installing a temporary cover over the base COMPRESSOR TROUBLESHOOTING IMPORTANT The troubleshooting contained in this section considers the compressor as an integrated component of the overall air brake charging system and assumes that an air dryer
61. s found again stop the BASIC test and consult the air dryer s Service Data sheet troubleshooting section 30 Appendix A continued Information about the BASIC Test kit Bendix P N 5013711 Filling in the Checklist for the Bendix Air System Inspection Cup BASIC Test Note Follow all standard safety precautions For vehicles using a desiccant air dryer STEP C How to Use the BASIC Test 1 Record days since air 9 Record amount 3 Action to tanks were last drained of oil found take The Technician uses the chart label on the BASIC test cup to help decide the action to take based on the amount of oil found Use the lower Y y acceptance line for low air use vehicles and upper If number of days is poe i ar cau System OK eS line for high air use vehicles from Step A 30 60 days high air 7 Pare oe a MOST Return to services of days use OF if oil level is above 30 30 ae M air use acceptance line for number Go to Step D of days gt if oil level is at or below System OK G Otherwise 30 day acceptance line gt gt Return to service if the number of days is Stop inspection unknown or outside the if oil level is above 30 day Test again limits above acceptance line gt after 30 days See Footnote 2 BASIC Test Example An oil level of 4 units in a sixty day period is within the acceptance area at or below the line for both low and high air use vehicles Return the vehicle to
62. seal bottom cover plate using RIV silicone sealant gt Replace compressor gt Replace compressor gt Clean compressor and check periodically Check air brake charging system Check that regular maintenance is being performed Return the vehicle to service An optional kit Bendix piece number 5011327 for the Bendix AD IS or AD IP air dryers or 5003838 for the Bendix AD 9 air dryer is available to redirect the air dryer exhaust Symptom What it may indicate 4 0 Oil in Supply or Maintenance Service Reservoir air dryer installed If a maintained Bendix a If air brake charging system maintenance has not been PuraGuard system filter performed or Bendix PuraGuard That is reservoir s have not been QC oil coalescing filter drained per the schedule in Table is installed call Aon page 15 Column 4 and or the 1 800 AIR BRAKE air dryer maintenance has not 1 800 247 2725 and been performed as in Column 3 speak to a Tech Team member bo If the vehicle maintenance has been performed as recom mended in Table A on page 15 some oil in the reservoirs is normal if See Table A on page 15 for maintenance schedule information Drain all air tanks reservoirs into the Bendix BASIC test cup Bendix kit P N 5013711 Duty cycle too high c Air brake system leakage d Compressor may be undersized for the application The duty cycle is the ratio of time the com
63. t flowing from the engine s cooling system through connecting lines enters the head and passes through the head s water jacket and back to the engine Proper cooling is important in maintaining discharge air temperatures below the maximum 400 F recommended FIGURE 7 POLYURETHANE SPONGE STRAINER FIGURE 9 COMPRESSOR INTAKE ADAPTER PREVENTIVE MAINTENANCE Regularly scheduled maintenance is the single most important factor in maintaining the air brake charging system Refer to Table Ain the Troubleshooting section for a guide to various considerations that must be given to the maintenance of the compressor and other related charging system componenis Every month 300 operating hours or after each 10 000 miles depending on the operating conditions experience and the type of strainer used service the air strainer POLYURETHANE SPONGE STRAINER EVERY 9000 MILES OR 150 OPERATING HOURS Remove and wash all of the parts The strainer element should be cleaned or replaced If the element is cleaned it should be washed in a commercial solvent or a detergent and water solution The element should be saturated in clean engine oil then squeezed dry before replacing it in the strainer Be sure to replace the air strainer gasket if the entire air strainer is removed from the compressor intake DRY ELEMENT PLEATED PAPER AIR STRAINER EVERY 20 000 MILES OR 800 OPERATING HOURS Remove the spring clips from either side of mounting b
64. the wrist pin bushings if they were removed Crankcase Remove the key or keys from the crankshaft and any burrs from the crankshaft where the key or keys were removed Note Through Drive Compressors may have a crankshaft key at both ends Remove the four cap screws securing front or drive end end cover or flange adapter Remove the end cover taking care not to damage the crankshaft oil seal or front main bearing if any Remove both of the small seal rings from the crankcase and the o ring from around the front end cover Remove the four cap screws securing the rear end cover and remove the rear end cover taking care not to damage the rear main bearing if any Remove both of the small seal rings from the crankcase and the o ring from around the end cover If the compressor has ball type main bearings press the crankshaft and ball bearings from the crankcase then press the ball bearings from the crankshaft Remove the unloader spring spring saddle and spring seat from the inlet cavity of the crankcase using long nose pliers Remove the unloader plungers and guides Cover the inlet cavity with a shop rag and apply air pressure to the governor mounting pad unloader port to blow the unloader pistons out of their bores and into the inlet cavity CLEANING OF PARTS General All parts should be cleaned in a good commercial grade solvent and dried prior to inspection Cylinder Head Remove all the carbon deposits from the discharge
65. ure to one of the coolant ports with all others plugged and check for leakage by applying a soap solution to the exterior of the body If leakage is detected replace the head End Covers Check for cracks and external damage If the crankshaft main bearings are installed in the end cover check for excessive wear and flat spots and replace them if necessary If the compressor has an oil seal in the end cover it should be removed by pressing it out of the end cover Crankcase Check all crankcase surfaces for cracks and damage On compressors where ball bearing main bearings are used the difference between the O D of the outer race and the I D of the crankcase hole should be 0000 in to 0015 in loose This is to maintain the correct press fit The crankcase must be replaced if the fit is too loose FIGURE 11 MEASURING CYLINDER BORES 8 On compressors fitted with precision sleeve main bearings the difference between the O D of the crankshaft journal and the main bearing I D must not exceed 0065 in If the clearance is greater than 0065 in the end cover or main bearing must be replaced Check the unloader bore bushings to be sure they are not worn rusted or damaged If these bushings are to be replaced they can be removed by running a 1 8 in pipe thread tap into the bushing and inserting a 1 8 in pipe threaded rod and pulling the bushing straight up and out Do not use an easy out for removing these bushings
66. ve to small amounts of oil consider a Bendix PuraGuard QC oil coalescing filter gt If outside the normal range go to Symptom 4 0 c Also see the Table A on page 15 column 3 for recommended air dryer cartridge replacement schedule Go to Test 2 on page 26 See Table A column 1 on page 15 for recommended compressor sizes gt If the compressor is too small for the vehicle s role for example where a vehicle s use has changed or service conditions exceed the original vehicle or engine OE spec s then upgrade the compressor Note The costs incurred e g installing a larger capacity compressor etc are not covered under original compressor warranty gt lf the compressor is correct for the vehicle go to Symptom 4 0 e Symptom What it may indicate 4 0 Oil in Supply Temperature or Service Reservoir e Air compressor discharge and or air dryer installed air dryer inlet temperature too high continued f Insufficient coolant flow ms Testing the temperature Inspecting the coolant hoses at the discharge fitting g Restricted discharge line Kinked discharge line shown Other h Restricted air inlet not enough air to compressor Partly collapsed inlet line shown What you should do gt Check temperature as outlined in Test 3 on page 26 If temperatures are normal go to 4 0 h gt Inspect coolant line Replace as necessary I D is 1 2 gt Insp
67. w If instead ice blockages occur at the air dryer or reservoir inlet insulation may be added here or if the inlet fitting is a typical 90 degree fitting it may be changed to a straight or 45 degree fitting Shorter discharge line lengths or insulation may be required in cold climates While not all compressors and charging systems are equipped with a discharge line safety valve this component is recommended The discharge line safety valve is installed in the cylinder head Tu Flo 550 750 or close to the compressor discharge port and protects against over pressurizing the compressor in the event of a discharge line freezeup p 3 STROKE FIGURE 5 COMPRESSION DISCHARGE VALVE STROKE FIGURE 6 UNLOADING 4 TO RESERVOIR INLET VALVE UNLOADER PLUNGER TO GOVERNOR TO RESERVOIR INLET VALVE UNLOADER PLUNGER no aT INTAKE TO RESERVOIR INLET VALVE UNLOADER PLUNGER DISCHARGE LINE TEMPERATURE When the temperature of the compressed air that enters the air dryer is within the normal range the air dryer can remove most of the charging system oil If the temperature of the compressed air is above the normal range oil as oil vapor is able to pass through the air dryer and into the air system Larger diameter discharge lines and or longer discharge line lengths can help reduce the temperature The air dryer contains a filter that collects oil droplets anda desiccant bed that removes

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