Jeep Wrangler/YJ 1987-1995 Repair Guide

Power Brake Booster



See Figures 1 and 2

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Fig. Fig. 1: Power brake booster mounting-with ABS

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Fig. Fig. 2: Brake pedal sensor mounting-with ABS

  1. Pump the brake pedal until all vacuum is exhausted from the power brake booster.
  3. Disconnect the pedal travel sensor.
  5. Remove the air cleaner and hoses.
  7. Remove the clamps that secure the reservoir hoses to the HCU pipes, then remove the hoses from the pipes.
  9. Disconnect the brake lines at the master cylinder.
  11. It may be necessary to remove the combination valve bracket bolt.
  13. Remove the nuts attaching the master cylinder to the booster mounting studs. Pull the cylinder forward and off the studs, then work it past the combination valve, brake lines, pedal travel sensor and out of the engine compartment.
  15. Disconnect the vacuum hose at the booster check valve.
  17. Disconnect the booster pushrod from the brake pedal.
  19. Remove the nuts attaching the booster to the passenger compartment side of the engine compartment, then slide the booster forward and out of the engine compartment.

To install:
  1. Position the booster on the dash panel, aligning the booster mounting studs with the holes in the panel, then install the attaching nuts and tighten to 30 ft. lbs. (41 Nm).
  3. Install the seal on the master cylinder.
  5. If installing a new pedal travel sensor on the original booster, the color dot on the booster shell must be the same as the color of the cap on the sensor. If the colors do not match, select the color cap from the kit supplied with the new sensor and install it on the end of the sensor plunger.

The cap on the sensor plunger and the dot on the shell are color coded for identification, to ensure they are used as matched sets.

  1. Install the O-ring on the pedal travel sensor.
  3. Install and firmly seat the sensor retaining ring on the booster flange.
  5. Insert the sensor into the booster, making sure it is firmly seated and engaged in the retaining ring.