Brakes
1967 Pedal Car Champion
Joined: Mar 2020
Posts: 9,135
Likes: 4,244
From: US-PNW
The bore size is only dependent on power vs. manual brakes. The power master cylinder is a larger bore; manual smaller bore. Buy the one spec'd for what you have. Same with the plunger rod depth - buy master spec'd to your year and brake setup. There is some adjustability on some power brake rods (not sure about manual brakes) but you need to be able to measure the depth of the cylinder's piston "pocket" and compare it to the projection on the power brake booster. There is a relatively inexpensive gauge to do this about $10.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
Yep. The push rod needs to be the same length as the pocket in which it fits. If the rod is too short, there is extra 'slop' in the pedal before the brakes start to apply. If the rod is too long, there is NO slop in the pedal before brakes are applied. Neither is a good situation.
