BENDIX BW2676 Fascicule

   

Broken, Cracked, or Loose 

 

 

 

Replace

   

Mounting Flange 

 

 

 

   

Oil Leaks 

 

 

 

Exterior leaks at the gaskets. 

Exterior leaks at the gaskets are a sign of loose or broken parts. 

   

 

 

 

 

 

 Excessive oil at the head gasket can indicate over pressurized 
condition.

   

Discoloration 

 

 

 

Compressor Head Discoloration or Rust 

Discoloration or rust can be an indication that the compressor is

   

 

 

 

 

 

 running hot. High operating temperatures will cause excessive 
oil carry over and will shorten the life of the compressor.

   

Condition of Inlet Line.  

 

 

 

A broken, bent, kinked, or restricted Inlet Line, or a  

A restricted inlet will cause slow pressure build and oil to pass

   

Engine Air Filter. 

 

 

 

poorly maintained inlet air fi lter or engine air fi lter. 

into the air system. An inlet open to atmosphere and/or a poorly

   

 

 

 

 

 

maintained engine air fi lter will allow dirt to enter the compressor.

   

 

 

 

 

 

 Compressor life will be signifi cantly reduced as a result.

   

Condition of Discharge Line 

 

 

 

Bent, Kinked, Porous or Restricted Discharge Line. 

A restricted discharge line will cause slow pressure build and the

   

 

 

 

 

 

 compressor to run hot. Compressor life will be signifi cantly 
reduced and could cause engine damage.

  Governor
   

Broken or Loose Mounting 

 

 

 

Replace 

Some governors are mounted at the air dryer. They require a

   

Components 

 

 

 

 

special mounting gasket and are normally set to cut out at 130 PSI.  

   

Exhaust Port Location 

 

 

 

The governor should be mounted so the exhaust port 

If the governor’s exhaust port can’t be mounted pointing down, an

   

 

 

 

 

is pointing down. 

 exhaust check valve may be installed to stop contamination from 
entering the port. Contamination will reduce the life of the governor.

  Air Dryer
   

Broken or Loose Mounting  

 

 

 

Replace

   

Components 

 

 

 

   

The Air Dryer is Bypassed 

 

 

 

If the air dryer has been bypassed, make the necessary 

When the air dryer is bypassed, moisture enters the air system

   

 

 

 

 

repairs and drain all reservoirs. 

 and freezes. Moisture washes lubrication off of valves and creates 
rust. Contamination in the air system can cause brake failure.

   

Heater and Wire Condition 

 

 

 

Replace broken wires.  Make sure the plug is seated 

12v DC or 24v DC should be at the plug when the vehicles

   

 

 

 

 

properly. 

 ignition is turned on.  An inoperable heater will cause air dryer 
freeze up in cold weather. 

   

Excessive Oil at Exhaust 

 

 

 

Though some oil and water is normal at the exhaust 

Poor maintenance will cause premature valve failure and possible

   

Port 

 

 

 

port, excessive oil and water are an indication of poor 

system freeze up in colder temperatures. Never pour liquids

   

 

 

 

 

air dryer/ compressor maintenance. 

  Reservoirs
   

Broken or Loose Mounting 

 

 

 

Replace

   

Components 

 

 

 

   

Proper Drain Cock 

 

 

 

Air leaking with the drain cock in the closed position. 

FMVSS 121 requires drain cocks function properly so that

   

Operation 

 

 

 

Air won’t drain when the drain cocks are open. 

operation of the reservoir’s single check valves can be validated.

   

 

 

 

 

 

Leakage reduces compressor life.

  Drain Reservoirs
   

Contamination in Reservoirs 

 

 

 

Though some oil and water is normal in reservoirs, 

Excessive oil and water in the reservoirs takes up capacity which

   

 

 

 

 

excessive amounts are not. In order to determine what  causes the compressor to run longer and hotter leading to

   

 

 

 

 

is excessive it will be necessary to run an the Basic Oil  compressor failure. Contamination can exit the reservoirs and

   

 

 

 

 

Passing test. The test requires the vehicle to be retested  make it into the braking system. Contamination causes early

   

 

 

 

 

at a later date. 

 

valve failure and could cause loss of brakes.

BW2676 © 2011 Bendix Commercial Vehicle Systems LLC, a member of the Knorr-Bremse Group.  All Rights Reserved.  Visit www.bendix.com for additional information or talk to your Bendix Account Manager.

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