Basic instructions for PM to vacuum swap

Red Regal T

Senior Member
Joined
May 24, 2001
Remove the powermaster system. This is accomplished by removing the 15mm nuts securing the PM to the firewall. They are located on each side of the brake pedal. There are four. Two on each side. Remove these, using a long extension, deep 15mm socket and ratchet. Unfasten the brake lines from the MC and disconnect the booster rod from the brake pedal. Unplug the electrical connections from the PM and remove it.

Next job is to swap out the PM brake pedal. In order to do this, you need to drop the saddle that the pedal is attached to. The four studs that held in your powermaster are the main fasteners that holds the brake pedal saddle in place. After removing the PM the mounting bracket, there is still one more bolt holding the saddle in place. Looking directly at the brake pedal shaft, the bolt is threaded vertically up at the top of brake pedal. Only the head is visible. You should remove the brake light switch and the other switch above it that rest against the brake pedal shaft. Though they appear to be threaded in, they just pull out from the saddle. Take a long 3/8" extension with a 13mm socket. The bolt is about a half inch left of the pedal. Remove this bolt and the saddle will be free. You can remove the saddle completely and check to make sure the studs on booster bolts align with the holes in the saddle. You may have to tap them with a hammer to align. This will make installing the booster easier.

OK, now with the new brake pedal installed, you can install the booster. Make sure the pin is in the recess in the frontcenter of the booster. It can fall out. It just slides in loosely. Install the booster into the firewall and through the saddle and install the 15mm retaining nuts under your dash.

Next, before installing MC, you need to bench bleed it. Connect bleeder lines to MC and run the hose into the reservoir. Fill with clean brake fluid and then use a rod to push on the plunger of the MC. This will pump the air and old fluid into the reservoir. Keep pumping it until all air is removed. Add clean fluid and repeat until clean brake fluid is observed in the reservoir.

When this is done, you can attach the MC to the booster, reinstall the brake lines and you may be done. If there was no air in your brake lines before you attached the new MC, you will have a good pedal. If there was air in your lines, your brake lite will probably be on, your brake pedal will be low or go to the floor. This indicates air in your lines and you'll have to bleed all your wheels, working from the farthest wheel away, first, and so on. If you're by yourself, you can bleed each wheel cylinder by loosening the bleeder ****, attach a hose to it, and submerge the other end in brake fluid. Pump your pedal gently at least 5 or 6 times. Close the bleeder **** and move to the next wheel and repeat the procedure. Keep the MC filled with clean fluid as you go from wheel to wheel.

If you don't have a TTA vacuum block, you'll have to get your vacuum from the PCV vacuum hose. Purchase a 3/8" vacuum Tee from any parts store. Basically, cut into the pcv hose a right above the pcv valve and install the T in that line. Run a 3/8 fuel hose for vacuum. Run it to the check valve on the booster. This will provide adequate vacuum for your vacuum brake system.
 
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