Which master cylinder bore size to use for power disc Kelsey/Hayes

puertobob said

My 69 had the big master and wouldn’t stop. Called Dr Diff. He said 15/16” is. Correct. I have no more problems. Works awesome now.

Click to expand...

Right but ppl are gonna say only 6 percent more leg effort with larger bore master cylinder. I run 15/16 on mine too, manual brakes, and not much leg effort to stop car. The smaller bore does give pedal more travel but if brakes bled correctly not a problem