BENDIX BA-922 COMPRESSOR

FIGURE 1 - BA-922
®
COMPRESSOR
DESCRIPTION
The function of the air compressor is to provide and
maintain air under pressure to operate devices in the
air brake systems. The Bendix
®
BA-922
®
compressor
is a two cylinder reciprocating compressor with a rated
displacement of 31.6 cubic feet per minute at 1250 RPM.
The compressor consists of a water cooled cylinder head,
cooling plate, valve plate assembly and an integral air
cooled crankcase and cylinder block. The cast aluminum
cylinder head contains the required air and water ports as
well as two unloader pistons. The cast aluminum cooling
plate provides added cooling to, and is located between,
the cylinder head and valve plate assemblies. The valve
plate assembly consists of laminated brazed steel plates
which incorporate various valve openings and channels
for conducting air and engine coolant into and out of the
cylinder head.
The discharge valves are 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, connecting rods, crankshaft and related
bearings.
While not all compressors and charging systems are
equipped with an optional discharge line safety valve,
this component is recommended. The discharge line
safety valve is installed in the cylinder head or close to
the compressor discharge port and protects against over
pressurizing the compressor in the event of a discharge
line freeze up or blockage.
OPERATION
The compressor is driven by the vehicle engine and
functions continuously while the engine is in operation.
Actual compression of air is controlled by the compressor
unloading mechanism operating in conjunction with a
governor.
FIGURE 2 - BA-922
®
COMPRESSOR (CUT-AWAY)
Unloader (2)
Cooling
Plate
Piston Rod
Delivery
Port
Piston
Air
Intake
Unloader
Port
Discharge
Reed
Valves
Crankshaft
SD-01-700
BENDIX
®
BA-922
®
COMPRESSOR
Safety
Valve
Valve Plate
Assembly
Crankcase and
Cylinder Block
Cylinder
Head

BENDIX BA-922 COMPRESSOR Specifications

General

Brand	BENDIX
Model	BA-922 COMPRESSOR
Category	Air Compressor
Language	English

Summary

BENDIX BA-922 COMPRESSOR

DESCRIPTION

Provides overview of compressor function and components.

OPERATION

Explains how the compressor builds and controls air pressure.

LUBRICATION

OIL PASSING

Discusses issues related to oil presence in the air system.

COOLING

COMPRESSOR COOLING

Details methods and checks for compressor cooling.

PREVENTATIVE MAINTENANCE

AIR INDUCTION

Specifies requirements for air intake on the compressor.

COMPRESSOR DRIVE

COMPRESSOR UNLOADER & GOVERNOR

SERVICE TESTS: GENERAL

IN SERVICE OPERATING TESTS

Covers performance tests for compressor operation.

LEAKAGE TESTS

Details procedures for testing air system leakage.

Cylinder Head Leakage Test

Specific test for cylinder head gasket air leakage.

Inlet, Discharge & Unloader Tests

Tests for inlet, discharge, and unloader valve leakage.

COMPRESSOR REMOVAL & DISASSEMBLY

GENERAL

Provides an overview of the disassembly process and considerations.

MAINTENANCE KITS & SERVICE PARTS

Lists available kits and parts for service.

IMPORTANT! SAFETY INSTRUCTIONS

Crucial safety precautions to avoid injury or death during service.

REMOVAL

Steps for removing the compressor from the vehicle.

CLEANING OF PARTS

GENERAL

General guidelines for cleaning compressor components.

CYLINDER HEAD

Specific cleaning instructions for the cylinder head.

INSPECTION OF PARTS

CYLINDER HEAD & VALVE PLATE

Inspection criteria for head and valve plate surfaces.

END COVER OR END COVER ADAPTER

Checks for cracks, wear, and thread damage.

CYLINDER BLOCK

Inspection of cylinder block gasket surface for damage.

DISCHARGE LINE

Checks for kinks, damage, or carbon deposits in the discharge line.

ASSEMBLY

CRANKCASE COVER

Procedure for installing the crankcase cover.

CRANKCASE END COVER OR ADAPTER

Procedure for installing the crankcase end cover.

CYLINDER HEAD

Steps for assembling the cylinder head components.

INSTALLING THE COMPRESSOR

TESTING REBUILT COMPRESSOR

BA-922 COMPRESSOR SPECIFICATIONS

Advanced Troubleshooting Guide for Air Brake Compressors

Introduction to the Air Brake Charging System

Table A: Maintenance Schedule and Usage Guidelines

Air Brake Charging System Troubleshooting

WARNING! SAFETY PRECAUTIONS

Essential safety guidelines for performing maintenance and tests.

Compressor System Tests

Test 1: Excessive Oil Leakage at Head Gasket

Procedure to check for oil weeping from the head gasket.

Test 2: Air Brake System and Accessory Leakage

Method for detecting air leaks in the brake system.

Test 3: Compressor Discharge & Air Dryer Inlet Temp

Checks compressor and dryer inlet temperatures.

Test 4: Governor Malfunction

Procedure to diagnose governor malfunctions.

Test 5: Governor Control Line

Checks the governor control line installation and condition.

Test 6: Compressor Unloader Leakage

Tests for leaks in the compressor unloader mechanism.

Appendix A: BASIC Test Kit Information

BASIC Test Procedure Steps

Guides for performing the BASIC Test and interpreting results.

Appendix B: Technical Bulletins

Bulletin TCH-008-021: Cold Weather Operation Tips

Guidance for operating air brakes in cold weather conditions.

Engine Idling Recommendations

Advice on minimizing engine idling to prevent freeze-ups.

Discharge Line Guidelines

Recommendations for discharge line length and insulation.

High Duty Cycle Vehicle Guidelines

Specific recommendations for high duty cycle vehicles.

System Leakage Checks

Methods for checking air brake system leakage.

Reservoir Draining

Importance and procedure for draining reservoirs.

Alcohol EvaporatorInjector Systems

Operation and maintenance of alcohol systems.

Air Dryers

Information on air dryer operation and service.

Thawing Frozen Air Lines

Tips for preventing and thawing frozen air lines.

Supporting Air and Electrical Lines

Ensuring proper support for lines to prevent damage.

Automatic Drain Valves

Maintenance and checking of automatic drain valves.