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17

Symptom: 

What it may indicate: 

What you should do: 

(e) Air  compressor  discharge  and/or  

air  dryer  inlet  temperature  too 

high.

(f) Insufficient coolant flow.

(g) Restricted discharge line.

 

Check temperature as outlined in Test 3 on 

page 24.  If temperatures are normal go to 

4.0(h).

 

Inspect coolant line. Replace as necessary 

(I.D. is 1/2"). 

 

Inspect  the  coolant  lines  for  kinks  and 

restrictions and fittings for restrictions. 

Replace as necessary.

 

Verify coolant lines go from engine block to 

compressor and back to the water pump. 

Repair as necessary.

 

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 13 for recommended size. Replace 

as necessary.

 

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. 

Temperature

Other

 

Check compressor air inlet line for restric-

tions,  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.

 

Check  the  engine  air  filter  and  service  if 

necessary (if possible, check the air filter 

usage indicator).

(h) Restricted air inlet (not enough air 

to compressor).

(g)

4.0  Oil in Supply 

or Service  

Reservoir*

(air dryer installed)

(continued)

Kinked discharge line shown.

Partly 

collapsed 

inlet line 

shown.

Testing the temperature 

at the discharge fitting.

Inspecting the coolant hoses.

*If a maintained Bendix

®

 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.

(g)

(e)

(f)

(h)

Summary of Contents for BA-922 COMPRESSOR

Page 1: ...e part of the valve plate assembly The cylinder head with the cooling and valve plates comprise a complete cylinder head assembly The cast iron crankcase and cylinder block assembly houses the pistons...

Page 2: ...hes the cutout setting of the governor the governor delivers system air to the compressor unloader port Air entering the unloader port acts on the unloader piston causing it to move away from its seat...

Page 3: ...oolant ow connections See the tabulated technical data in the back of this manual for speci c requirements PREVENTATIVE MAINTENANCE Regularly scheduled maintenance is the single most important factor...

Page 4: ...rticularly oil sensitive systems the Bendix PuraGuard system lter can be used in conjunction with a Bendix air dryer If compressor oil passing is suspected refer to the TROUBLESHOOTING section and TAB...

Page 5: ...he performance degrades signi cantly over time you may use the Advanced Troubleshooting Guide for Air Brake Compressors starting on page 11 of this document to assist your investigation of the cause s...

Page 6: ...this will require that the vehicle be prevented from moving by other means for the duration of these tests procedures 2 Stop the engine and remove ignition key when working under or around the vehicle...

Page 7: ...s leading to the compressor 3 Remove as much road dirt and grease from the exterior of the compressor as possible FIGURE 9 BA 922 COMPRESSOR EXPLODED VIEW OF SERVICEABLE PARTS Item Qty Description Ite...

Page 8: ...e balance piston 4 and its spring 5 from the cylinder head 5 Remove the six hex head bolts and washers from the cylinder head 6 Remove the two bolts located in the center of the head Gently tap the he...

Page 9: ...y 12 Example 12 Inch Pounds 1 Foot Pound 12 FOOT POUNDS TO INCH POUNDS To convert foot pounds to inch pounds of torque multiply foot pounds by 12 Example 1 Foot Pound x 12 12 Inch Pounds CRANKCASE COV...

Page 10: ...o all lines reconnected during installation and check for air oil and coolant leaks at compressor connections Also check for noisy operation TESTING REBUILT COMPRESSOR In order to properly test a comp...

Page 11: ...Test Information 26 28 Test Procedures Maintenance Schedule and Usage Guidelines Table A 13 Symptom Page Number Maintenance Usage Guidelines TORQUE SPECIFICATIONS Assembly Torques in inch pounds in I...

Page 12: ...perating in a temperate climate See Bendix and or other air dryer manufacturer guidelines as needed When the temperature of the compressed air that enters the air dryer is within the normal range the...

Page 13: ...days Every Month Every 3 Years Every 2 Years Every Year I D Vehicle Used for Column 1 Column 2 Column 3 Column 4 Column 5 Regularly scheduled maintenance is the single most important factor in mainta...

Page 14: ...TION 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 as semble...

Page 15: ...011327 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 3 0 Oil at air dryer purge exhaust or surrounding area c 2 0 Oil...

Page 16: ...ithin the acceptable level If within the normal range return the vehicle to service For vehicles with acces sories that are sensitive to small amounts of oil consider a Bendix PuraGuard QC oil coalesc...

Page 17: ...nlet insulation may be added here or if the inlet tting is a typical 90 degree tting it may be changed to a straight or 45 degree tting For more information on how to help prevent discharge line freez...

Page 18: ...tests all air brake system pneumatic components need to be able to pass including minimum levels of tolerance to contamination 5 0 Oil present at valves e g at exhaust or seen during servicing Air br...

Page 19: ...ay be undersized for the application d Compressor unloader mechanism malfunction e Damaged compressor head gasket Using dash gauges verify that the compressor builds air system pressure from 85 100 ps...

Page 20: ...line see Table A column 2 on page 13 for recommended size and go to Test 3 on page 24 By other restrictions e g kinks Re place the discharge line See Table A col umn 2 on page 13 for recommended size...

Page 21: ...orm and block the ow If instead ice blockages occur at the air dryer inlet insulation may be added here or if the inlet tting is a typical 90 degree tting it may be changed to a straight or 45 degree...

Page 22: ...Test 4 on page 25 Go to Test 2 on page 24 Go to Test 5 on page 25 12 0 Air dryer safety valve releases air a Restriction between air dryer and reservoir b Air dryer safety valve malfunction c Air drye...

Page 23: ...t the head gasket may indicate 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...

Page 24: ...ry Test 2 Air Brake System and Accessory Leakage Caution The temperatures used in this test are not normal vehicle conditions Above normal temperatures can cause oil as vapor to pass through the air d...

Page 25: ...to and from the governor for restrictions e g collapsed or kinked Repair as necessary 2 Using a calibrated external gauge in the supply reservoir service reservoir or reservoir port of the D 2 govern...

Page 26: ...ician inspects items drained and f days Use Test 2 Air Leakage Use Test 2 Air Leakage NO Re test with the BASIC Test after 30 days NO did not know when last drained Was the number of days since last d...

Page 27: ...l loss amount described ______________ Is the engine leaking oil no yes Is the compressor leaking oil no yes Other complaint _____________________________________ No customer complaint Checklist for T...

Page 28: ...h air use or 30 90 days low air use if oil level is at or below acceptance line for number of days if oil level is above acceptance line for number of days System OK Return to service Otherwise if the...

Page 29: ...ome periods of extended engine idling can not be avoided Discharge Lines The discharge line should slope downward from the compressor discharge port without forming water traps kinks or restrictions C...

Page 30: ...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 consump...

Page 31: ...c 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 uids into air brake lines or hose couplings glad...

Page 32: ...32 BW2398 2005 Bendix Commercial Vehicle Systems LLC All rights reserved 10 2005 Printed in U S A...

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