Chrysler Front Wheel Drive Cars 4-CYL 1981-1995 Repair Information

Power Brake Booster

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REMOVAL & INSTALLATION




WARNING
On vehicles equipped with a Bendix Type 6 Anti-lock Brake System (ABS), a Diagnostic Readout Box (DRB or DRB II) is necessary for brake system bleeding. Failure to use a DRB to bleed the system will lead to system failure. Refer to the ABS portion of this section for bleeding procedures and precautions.

Except Premier

See Figures 1 and 2

Click image to see an enlarged view

Fig. Fig. 1: The power brake vacuum booster is a sealed component, which does not require any adjustments



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Fig. Fig. 2: The master cylinder is mounted to the booster, which, in turn, is mounted to the fire wall of the vehicle

  1. Remove the brake lines from the master cylinder.
  2.  
  3. Remove the nuts attaching the master cylinder to the brake booster, and remove the master cylinder. For more details, refer to the master cylinder removal procedure earlier in this section.
  4.  
  5. Release its tension with a pair of pliers and slide the vacuum hose retaining clamp back from the check valve. Then, disconnect the vacuum line supplying the brake booster at the check valve. Do not remove the check valve. On models with manual transaxles; remove the clutch cable mounting bracket, then pull the wiring harness up and away from the strut tower.
  6.  
  7. Working underneath the instrument panel, remove the retainer clip from the brake pedal pin. To do this, position a small, bladed instrument between the center tang of the retainer clip and the pin on the brake pedal and twist it. Use this method to cause the tang on the clip to pass over the end of the brake pedal pin. Discard the retainer clip because it will no longer lock safely.
  8.  
  9. Remove the brake light switch and striker plate.
  10.  
  11. Remove the four power booster attaching nuts.
  12.  
  13. Remove the booster from the car. The power brake booster is not repairable. Do not attempt to disassemble it.
  14.  

To install:
  1. Position the booster on its mounting bracket and install its four mounting nuts. Torque them to 21 ft. lbs. (28 Nm).
  2.  
  3. Coat the load bearing surface of the brake pedal pin with Lubriplate® or equivalent to reduce wear. Then, connect the pushrod to the pedal pin and install a new retaining clip through the end. Lock the retaining clip securely.
  4.  
  5. Position the master cylinder onto the brake booster, install the mounting nuts and torque them to 21 ft. lbs. (28 Nm).
  6.  
  7. Route the vacuum hose carefully to the booster, ensuring that it is not kinked or pinched. Then, position its retaining clamp carefully.
  8.  
  9. Install each brake hydraulic tube into its correct master cylinder opening and torque the retaining flare nut to 12 ft. lbs. (16 Nm)
  10.  
  11. Slide the wiring harness down over the strut tower and reinstall the retaining clips. On models equipped with manual transaxles, install the clutch cable mounting bracket.
  12.  
  13. Bleed the brake system, making sure to keep the master cylinder full of the approved brake fluid throughout the procedure. Make sure the unit is filled to the correct level when bleeding is completed. Road test the vehicle for proper operation.
  14.  

Premier

See Figures 3 and 4

Click image to see an enlarged view

Fig. Fig. 3: Detach the brake booster pushrod from the brake pedal by removing the spring clip-a new clip is needed for installation



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Fig. Fig. 4: Transfer the check valve (if still functional; otherwise, replace with a new one) and seal to the new booster

  1. Disconnect the negative battery cable.
  2.  
  3. Disconnect the vacuum line from the booster.
  4.  
  5. Remove the clip retaining the throttle cables to the bracket on the booster.
  6.  
  7. Remove the master cylinder. For more details, refer to the appropriate master cylinder (ABS or non-ABS) procedures located later and earlier (respectively) in this section.
  8.  
  9. From inside the vehicle, remove the wiring harness connector from the brake light switch. Remove the pushrod from the brake pedal.
  10.  
  11. Remove the booster retaining nuts, then remove the booster from the firewall of the engine compartment. Inspect the seal for damage.
  12.  

To install:
  1. Transfer the check valve, seal and the new gasket to the replacement booster.
  2.  
  3. Install the booster to the firewall and connect the pushrod to the brake pedal. Make sure to use new nuts on the pushrod bolt-do not reuse the old nuts.
  4.  
  5. Install the booster mounting nuts, then tighten them to 18 ft. lbs. (24 Nm).
  6.  
  7. Attach the brake light switch electrical wiring harness connectors.
  8.  
  9. Install the master cylinder, proportioning valve and valve bracket. Clip the throttle cables in place.
  10.  
  11. Install and tighten all brake lines to 161 inch lbs. (20 Nm).
  12.  
  13. Connect the negative battery cable and bleed the brake system.
  14.  

 
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