GM Celebrity/Century/Ciera/6000 1982-1996 Repair Guide

Proportioning Valves

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REMOVAL & INSTALLATION



External Type

The external valves are used on 1982-86 models.

  1. Disconnect and cap the brake line from the proportioning valve(s).
  2.  
  3. Using a suitable wrench remove the proportioning valve(s) from the master cylinder.
  4.  

If both proportioning valves are removed at the same time, make sure the proportioning valves are installed in the correct places. The threads on the two valves differ slightly and installation in the wrong port can damage the master cylinder or proportioning valves. If the valves are replaced both valves must be the same color code.

  1. Remove the old O-rings and discard.
  2.  

To Install:
  1. Install new O-rings on the proportioning valve(s).
  2.  
  3. Install the proportioning valve(s) and tighten to 24 ft. lbs. (32 Nm).
  4.  
  5. Connect the brake line(s) to the proportioning valve(s) and tighten the fittings to 24 ft. lbs. (32 Nm).
  6.  
  7. Bleed the brake system.
  8.  

Internal Type

The internal proportioning valves are used on 1987-96 models.

  1. Remove the master cylinder from the vehicle.
  2.  
  3. Remove the brake master cylinder reservoir.
  4.  
  5. Remove the proportioning valve cap assemblies.
  6.  
  7. Remove the O-rings from the caps and discard of them.
  8.  
  9. Remove the springs, then use needle nose pliers to remove the proportioning valve pistons. If you are not careful you could damage the piston stems.
  10.  
  11. Remove the piston seals and pistons from the cylinder.
  12.  

To install:
  1. Inspect the pistons for any corrosion or deformation, replace them if needed.
  2.  
  3. Clean all the parts in denatured alcohol, then dry with compressed air.
  4.  
  5. Lubricate the new O-rings, valve seals, stem, and valve pistons with silicone grease.
  6.  
  7. Install the new seals on the valve pistons with the seal lips facing upward toward the cap assembly.
  8.  
  9. Install the pistons and seals in the master cylinder body. Insert new O-rings in the grooves of the proportioning valve cap assemblies. Install the caps to the cylinder body.
  10.  
  11. Tighten the caps to 20 ft. lbs. (27 Nm). Install the reservoir assembly.
  12.  
  13. Bleed the brake system, then check the system for proper operation. Do not move the car until a hard brake pedal is obtained.
  14.  
  15. Close the hood.
  16.  

 
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