Vacuum Brake Swap
Scott Simpson
Parts Needed
The following parts are needed to perform this swap from a1987 non-turbo Regal :
  • Master Cylinder
  • Vacuum assist canister
  • Brake pedal and bracket
  • Check valve
  • large vacuum hose
  • Electrical tape
  • Brake fluid ~ 1 gallon.

(See Eric Fisher's article in the GS-XTRA for GM part numbers including TTA vacuum block)

Remove Powermaster

    Apply brakes 10 times with key off to de-pressurize. Remove electrical connectors at switch and motor. Remove pedal and bracket assembly from under dash. Drain fluid out of reservoir and remove the two brake line pipes from the master cylinder. Remove the two nuts holding the Powermaster assembly to the firewall. Unit can be removed as a whole. Go back under the dash and remove the bolt adapter bracket (2 into engine bay/4 into drivers compartment for brake pedal bracket.) Put tape on connectors.

Install Vacuum brake master cylinder

    Start with the Vacuum assist canister and brake pedal bracket. (Assembly is easier if you connect everything before tightening.) Attach Master cylinder to vacuum canister. Insert new check valve in canister and run large vacuum hose to a vacuum source at engine (Turbo TA vacuum manifold works here.) Add fluid to master cylinder, have someone lightly press brake pedal once or twice until fluid comes out of the two ports and connect the brake pipes.

Finishing Up
Bleed all four corners starting at Passenger side rear, then Driver rear, Front passenger, Driver front caliper making sure the reservoir does not go dry.

Assuming no leaks, you will notice a much "sturdier" feeling brake pedal. The vacuum reservior holds plenty of vacuum so aftermarket "add-on" cannisters are not necessary. The check valve is a one-way valve, so no amount of boost is going to effect the braking power.

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