BEARING ASSEM. 6D7884 - Caterpillar

Table 1
Possible Component Root Causes Non-Component Root Causes How to Diagnose Corrective Action
Front/Rear ARC Solenoid Valves Contamination Perform brake system pressure check. If the pedal pilot pressure and relay spring bias is correct, but the brake pressure with manual retarder or ARC pressure is not, then there may be an issue with front or rear ARC solenoid. ServicewithNew ARC solenoid valve. Make sure that oil is ISO 18/15 or better.
Relay Valve (Front/Rear Service Brakes) Contamination
Out of Adjustment Perform brake system pressure check. The pressure at the slack adjuster should be 240 +/- 35 kPa (35 +/- 5 psi) less than the brake pedal pilot pressure. If the spring bias on the relay valves is too high, the brake pressure will be low. (If XLP package is installed front brake slack adjuster pressure will be 193 +/- 35 kPa less than brake pedal pressure.) Service with kit for the Relay valve (service brakes). Make sure that oil is ISO 18/15 or better.
Brake Pedal Valve Contamination Perform brake system pressure check. The brake pedal pilot pressure must be within specifications. Service with new pedal valve. Make sure that oil is ISO 18/15 or better.
Brake Pack (Seal Damage) Over pressurization Apply retarder and service brakes independently and measure the pressure at the brake packs. All four pressures should be within tolerance. Replace if one or more brake packs is lower than the others. Inspect for seal damage.