Hi all,

Happy New Year to everyone. I have installed 4-wheel discs from SSBC on my '69 superbee. The fronts are the 4-piston and the rear are the single piston units. I had read on here at some point about some folks having pedal effort problems which were attributed to the used of the larger bore master cylinder (SSBC provides a 1 1/32" M/C). I chose to install the system with a wilwood aluminum large volume 7/8" bore M/C. The brakes work, but the pedal is rubbery and will not lock up the brakes. I spoke to a tech at SSBC and he informed me that my problem was that i did not use their M/C and that the bore in the Wilwood was too small to provide enough fluid volume/pressure for the system and that i should install the unit that they provided.

Does anyone/everyone agree that this sounds correct? Dr. Diff?

If this is the case, I will order the newer style unit sold by Mancini....or can i get a newer style aluminum/plastic unit at the parts store that has a 1 1/32 bore?

Any help would be appreciated.

i am very certain that it is bled correctly......i have bled and re-bled all 4 corners about 3 times......and the M/C was bench bled correctly as well. If there is a consensus that this might be the problem...i will have at it again.

I have sold many 15/16" bore aluminum master cylinders to people who have installed the "recommended" 1 1/32" bore master on SSBC brakes and were unsatisfied with braking performance. BTW, I'm the only source for this master cylinder.

i am not quite sure i follow your response...are you saying that the 7/8" bore wilwood i am using is not appropriate, but the 15/16" unit you sell is? I am not being sarcastic, just clarifying.

Does my problem even make sense?

I'm not really familiar with SSBC brakes, other than through feedback I have received from customers who have bought my master cylinders.

The 7/8" Wilwood master will build lots of pressure, but the pedal will be mushy. You should have plenty of braking, however.

15/16" bore is a compromise between pedal feel and line pressure for that system.

Check out this recent thread for insights on bore sizes and troubleshooting:

https://board.moparts.org/ubbthreads/show...rue#Post6325303