66-70 Chevy Fullsize, 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. NOTE: Booster pushrod may need to be trimmed to fit.
  3. Install the booster onto the original holes that mounted the original booster to the firewall. If the vehicle was equipped with manual brakes you need to remove the master cylinder studs so the booster will sit flush to the firewall.
  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.

2 Responses

  1. Salvador E. Chavez says:

    Just a question installed BB-C6670 I still seem to have air in system. I double checked for leaks no more. I did not remove master cylinder from assembly. Bled mastercylinder on with the powerbooster . Can you give me some advise.

    • admin says:

      You must bench bleed the master cylinder prior to installing it on the car. If you need any tech advise please call us at 800-638-1703

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