1989 Jeep Cherokee brakes problems

Defect

VEHICLE DESCRIPTION: VEHICLES EQUIPPED WITH ANTILOCK BRAKE SYSTEM (ABS). THE ANTILOCK BRAKE SYSTEM (ABS) HYDRAULIC CONTROL UNIT CAN EXPERIENCE EXCESSIVE BRAKE ACTUATOR PISTON SEAL WEAR WHICH COULD CAUSE PUMP-MOTOR DETERIORATION.

Consequence

IF THIS OCCURS, THE ABS FUNCTION WOULD BE LOSE AND REDUCED POWER ASSIST WOULD BE EXPERIENCED DURING VEHICLE BRAKING. THE INSTRUMENT PANEL WARNING LIGHTS WILL SIGNAL SYSTEM IMPAIRMENT AND THE BASE MANUAL BRAKES WILL REMAIN FUNCTIONAL.

Remedy

DEALERS WILL TEST THE VEHICLE'S ABS AND REPAIR AS NECESSARY. THE WARRANTY ON ALL ABS COMPONENTS WILL BE EXTENDED TO 10 YEARS OR 100,000 MILES (EXCEPT FOR THE BRAKE ACTUATOR PISTON ASSEMBLY AND THE PUMP-MOTOR ASSEMBLY WHICH WILL HAVE A LIFETIME COVERAGE). OWNERS WILL BE REIMBURSED FOR PREVIOUS ABS COMPONENT REPAIR COSTS.

Defect

THERE MAY BE HYDRAULIC FLUID CONTAMINATION FROM CONDENSATION FORMATION THAT CAN PLUG THE ABS BRAKE BOOSTER PUMP FILTER; STRESS CORROSION OF THE MASTER CYLINDER SNAP RING HAS BEEN TRACED TO CHLORINE LEAKING FROM THE LOW PRESSURE HYDRAULIC HOSE WHICH MAY CAUSE IT TO BREAK; FRONT BRAKE HOSE TO TIRE INTERFERENCE WHICH MAY CAUSE FAILURE OF THE BRAKE HOSE.

Consequence

CONTAMINATION OF THE HYDRAULIC FLUID CAN CAUSEMALFUNCTIONING OF THE ANTI-LOCK BRAKE SYSTEM; LOW PRESSURE HOSE LEAKAGE CAUSESLOSS OF BRAKE FLUID AND ALSO RESULTS IN CORROSION AND FAILURE OF THE MASTERCYLINDER SNAP RING, RESULTING COMPLETE BRAKE FAILURE; FAILURE OF THE FRONT BRAKEHOSE DUE TO HOSE TO TIRE INTERFERENCE WILL CAUSE FAILURE OF ONE HALF OF THEBRAKE SYSTEM RESULTING IN A LONGER STOPPING DISTANCE THAN EXPECTED.

Remedy

REPLACE ABS LOW PRESSURE HOSE; REBUILD MASTER BRAKE CYLINDER; INSPECT, SERVICE INTERFERENCE PROBLEMS, AND REPLACE FRONT BRAKE HOSE AS NECESSARY.