1977 master cylinder bore
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,113
From: Crossville TN
The bore sized are different for manual brakes or for power brakes. Just order a rebuild kit for the type MC you have and you should be fine. After rebuild, you will need to bleed the master cylinder of ALL air. If you do a 'bench' bleed, make sure that you do not over-stroke the MC piston as you pump the air out. If you do so, it will damage a seal. You can bleed the MC after you install it in the car...but BEFORE you hook up the brake lines. That way, you won't over-stroke the piston. Just don't push the brake pedal down too fast or you will spurt brake fluid out the [open] top.
