64-66 GM “A” Body, Power Booster Kit

January 21st, 2009


STEPS: Read these instructions carefully!
IMPORTANT: This kit is assembled for shipping
purposes only! Be sure to check all nuts and bolts for adequate torque prior to use. Don’t forget!

  1. Remove original master cylinder, pedal clevis and hard lines.
  2. Remove master cylinder from power booster as you will need to bench bleed it prior to bleeding the system. Inexpensive bleeder kits are available at any auto parts store for minimal cost. We also sell a bleeder kit. Install your pedal clevis onto booster.
  3. Install the booster onto the original studs that mounted the master cylinder to the firewall. You will find that there is a second set of studs in the firewall from the factory for this purpose.  NOTE: SOME FIREWALL STUDS WERE COURSE THREAD AND SOME WERE FINE THREAD, YOU WILL NEED TO SUPPLY THE APPROPRIATE NUTS FOR THE INSTALLATION!
  4. There should be two pedal clevis holes in the brake pedal (if not you will need to drill a 3/8” hole 1” lower than the original clevis hole in  pedal). Mount the clevis into the lower hole and check for proper adjustment by making sure the brake pedal is all the way up and no pressure is being applied to the booster. Be sure to tighten the clevis jam nut.
  5. Mount your bench bled master cylinder to the power booster. Connect all appropriate hard lines and bleed the system. NOTE: ON GM MASTER CYLINDERS, THE FRONT PORT IS FOR THE FRONT BRAKES AND THE REAR PORT IS FOR THE REAR BRAKES.
  6. If you are running disc brakes be sure to have the proper proportioning valve kit for your application.
  7. Double check all of your work and proceed to check the system for any leaks.
  8. Be sure to hook up your vacuum line to the appropriate port on the manifold.


  1. We highly recommend that you perform a vacuum check on your particular engine. Acceptable vacuum numbers would be from 15in/hg to 22in/hg. For those who have lower numbers we offer a vacuum pump. Call for details.
  2. We also offer disc brake master cylinders and proportioning valves for those who  do not want to run power brakes. Call for details.

Note: 2 piece line set sold separately.


2 Responses

  1. Johnny says:

    Installing the booster to firewall on 64 Chevelle the 4 bolt locations are not on a flat surface. .The original master cylinder had only 2 bolts on a flat surface The mounting bracket supplied on your unit requires 4 bolts on a flat surface to mount flush. What do I do to make it fit
    Thanks Johnny

    • admin says:

      There should be provisions on the firewall for the extra 2 mounting holes that are on our booster brackets. If not, mount the booster utilizing just the 2
      master cylinder studs. Then mark the other 2 holes using the brackets as a guide, remove, drill the firewall using a 13/32″ drill and the reinstall the booster. You will have to pick up
      2—3/8″ x 1″ bolts with lock nuts and washers.

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