GM Full-Size Trucks 1980-1987 Repair Guide

Power Boost Vacuum Brake System

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This system is primarily found on trucks equipped with gasoline engines. Two types of vacuum boosters are used, the single diaphragm type and the tandem diaphragm assembly.

REMOVAL & INSTALLATION



  1. Remove the two nuts holding master cylinder to power cylinder and position it away from the power cylinder. Do not disconnect hydraulic brake lines; be careful not to bend or kink pipes.
  2.  
  3. Disconnect the vacuum hose from the vacuum check valve on the front housing of the power head. Plug vacuum hose to prevent dust and dirt from entering hose.
  4.  
  5. Disconnect the power brake push rod from the brake pedal.
  6.  
  7. Remove the four nuts from the mounting studs which hold the power brake to the cowl.
  8.  

To install:
  1. Mount the power brake booster to cowl and tighten retaining nuts.
  2.  
  3. Connect the power brake push rod to the brake pedal.
  4.  
  5. Connect vacuum hose to vacuum check valve.
  6.  
  7. Connect master cylinder to booster and tighten nuts.
  8.  

 
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