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9

INSPECTION OF PARTS 

CYLINDER HEAD & VALVE PLATE  

1.  Carefully inspect the cylinder head gasket surfaces for 

deep gouges and nicks.  If detected, the compressor 

must be replaced.

2.  Carefully  inspect  the  valve  plate  assembly  gasket 

surfaces for deep gouges and nicks.  Pay particular 

attention to the metal gasket surface.  A metal gasket 

(12)  is  used  between  the  valve  plate  assembly  and 

cylinder  block.    This  surface  must  be  smooth  and 

free of all but the most minor scratching.  If excessive 

marring or gouging is detected, the compressor must 

be replaced.

3.  Inspect the cylinder head for cracks or damage.  With the 

cylinder head and head gasket secured to the valve plate 

assembly, apply shop air pressure to one of the coolant 

ports with all others plugged, and check for leakage by 

applying a soap solution to the exterior of the head.  If 

leakage is detected in the cylinder head casting, replace the 

compressor.

END COVER OR END COVER ADAPTER

Check  for  cracks  and  external  damage.    Check  the 

crankshaft main bearing surface in the end cover or end 

cover adapter, check for excessive wear and flat spots and 

replace the end cover if necessary.  Check for galling of 

the oil port threads and replace the end cover or end cover 

adapter if necessary.  Minor thread chasing is permitted but 

do not “recut” the threads if they are badly damaged.

CYLINDER BLOCK  

1.  Check the cylinder head gasket surface on the cylinder 

block for nicks, gouges, and marring.  A metal gasket 

is used to seal the cylinder head to the cylinder block.  

This surface must be smooth and free of all but the most 

minor scratching.  If excessive marring or gouging is 

detected, the compressor must be replaced.

DISCHARGE LINE

1.  Inspect the discharge line for kinks, damage, or carbon 

deposits.  Replace as necessary.  See the advanced 

troubleshooting guide for more information.

ASSEMBLY  

General  Note:

 All  torques  specified  in  this  manual  are 

assembly torques and typically can be expected to fall off 

after assembly is accomplished. 

 Do not re-torque

 after 

initial assembly torques fall unless instructed otherwise.  

A compiled listing of torque specifications is presented on 

page 11 of this manual.

INCH POUNDS TO FOOT POUNDS

To convert inch pounds to foot pounds of torque, divide 

inch pounds by 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 COVER

1.  Position the crankcase cover gasket (14) on either the 

crankcase or crankcase cover and install the crankcase 

cover  on  the  crankcase  using  the  four  cap  screws.  

"Snug" the four cap screws then torque to 62-71 inch 

pounds (7-8 Nm) using a crossing pattern.

CRANKCASE END COVER OR ADAPTER

1.  Install the end cover o-ring (13) on the crankcase end 

cover.

2.  Orient the crankcase end cover or end cover adapter to 

the crankcase using the reference marks made during 

disassembly.    Carefully  install  the  end  cover  or  end 

cover adapter in the crankcase making certain not to 

damage the crankshaft bearing surface in it.

3.  Install the four end cover screws or studs.  "Snug" the 

screws then tighten to 195 to 213 inch pounds (22-24 

Nm) using a crossing pattern.

CYLINDER HEAD

1.  Note the position of the protruding alignment pins on the 

cylinder block.  Install the metal inlet reed valve/gasket 

(12) over the alignment pins on the cylinder block.

2.  Position the valve plate assembly on the cylinder block 

so that the alignment pins in the cylinder block fit into 

the corresponding holes in the valve plate assembly.

3.  Position and install one of the metal gaskets (11) over 

the alignment bushings protruding from the valve plate 

assembly. When properly installed, the outline of the 

gasket matches the outline of the valve plate.

4.  Install the cooling plate over the alignment bushings 

protruding from the valve plate assembly. Again, when 

properly  installed,  the  outline  of  the  cooling  plate 

matches the outline of the valve plate.

5.  Position and install the other metal gasket (11) over the 

alignment bushings protruding from the cooling plate 

assembly. The outline of the gasket matches the outline 

of the cooling plate.

6.  Position and install the cylinder head over the alignment 

bushings protruding from the cooling plate.

Note:

 The alignment bushings will only fit into 

two of the six cylinder head bolt holes.

7.  Install the two center bolts and six hex head cylinder 

head bolts and washers and snug them, then tighten 

evenly to a torque of 265 to 292 inch pounds (30-33 

Nm) using the pattern shown in Figure 9.

8.  Install  the  unloader  piston  (7)  with  its  pre-installed  

o-rings (6, 8, 9) in the cylinder head making certain not 

to damage them in the process.

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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