See Figures 1 and 2
Fig. Fig. 1: Anti-lock brake system component locations
Fig. Fig. 2: Schematic of the anti-lock brake system component connections
The Bendix anti-lock braking system is available on 1989-91 Jeep Cherokee and Wagoneer vehicles (model designation XJ) with SelecTrac 4-wheel drive. Anti-lock Brake Systems (ABS) are designed to prevent wheel lockup under heavy braking conditions on virtually any type of road surface. The Jeep ABS limits wheel lockup by modulating the brake fluid pressure to the brakes at each wheel. A vehicle which is stopped without locking the wheels will normally stop in a shorter distance than a vehicle with locked wheels. Additionally, vehicle control can be maintained during hard braking because the front wheels do not lock. The Jeep system is an electronically operated, power assisted brake system controlled by an isolated Electronic Control Unit (ECU).
This brake system uses a hydraulic accumulator which, when fully charged, contains brake fluid at very high pressure. Before disconnecting any hydraulic lines, hoses or fittings be certain that the accumulator pressure is completely relieved. Failure to depressurize the accumulator may result in personal injury and/or vehicle damage.
Certain components within the ABS system are not intended to be serviced or repaired individually. Only those components with removal and installation procedures should be serviced.
Both the external accumulator and the smaller accumulator within the pump contain high pressure nitrogen charges to assistance in pressurizing the system. The gas pressure is maintained even after fluid pressure in the system is reduced. Never puncture or attempt to disassemble either of these components.
Do not use rubber hoses or other parts not specifically specified for the ABS system. When using repair kits, replace all parts included in the kit. Partial or incorrect repair may lead to functional problems and require the replacement of components.
Lubricate rubber parts with clean, fresh brake fluid to ease assembly. Do not use lubricated shop air to clean parts; damage to rubber components may result.
Use only DOT 3 or its superceding brake fluid from an unopened container.