Thread: Brake booster and MC

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Need to replace my MC and the booster. Changed rear brakes from from drum to disc and my master cyl. started leaking so I'm replacing both booster and M/C.
My question is, is the 7" booster double diagram ok with disc brakes front and rear and is the "standard" 1 inch bore Master cyl. ok ? I have an adjustable proportioning valve. Looking at the nice chrome sets that are out there on the net. Thanks for the inputs.

I have manual disc/disc brakes on my '34, using a Corvette manual disc/disc master cylinder w/ 1-1/8" bore and an Allstar Performance adjustable proportioning valve. I didn't have room for a power brake booster, but the car stops just fine. Based on that, I suspect that your choice would work OK. However, you might want to consider a 1-1/8" bore. It has a 27% hydraulic advantage over a 1" bore. The previous master cylinder on my '34 had a 1" bore, and the 1-1/8" bore feels significantly better.

I used a Right Stuff Detailing master cylinder - part # DBMC05C.

The 1-1/8" will produce less pressure and more volume. That would decrease pedal travel, but require more force. FWIW, I'm using a 7" dual diaphragm with a 1" bore to operate Wilwood discs. The car stops fine, but still requires more effort than any of my new cars. Very little pedal travel is used.

Originally Posted by daveS53

The 1-1/8" will produce less pressure and more volume. Whether would decrease pedal travel, but require more force. FWIW, I'm using a 7" dual diaphragm with a 1" bore to operate Wilwood discs. The car stops fine, but still requires more effort than any of my new cars. Very little pedal travel is used.

You are correct of course. My college fluid mechanics professor would be shaking his head. My only excuse is that it was really late when I posted that.