The Stovebolt Site Forums The Shop Area Driveline AD truck - dual master cylinder

There are a couple different versions of the “Corvette” master cylinder used in the dual reservoir conversion. One has a 1” bore and one has a 1-1/8” bore.

Anyone happen to know which is intended for drum/drum and which for disc/drum? I could have sworn the Jim Carter website used to call out the bore in their descriptions. But I don’t see it now.

Master cylinder bore diameter should be matched to wheel cylinder and/or caliper size. Do you have drum/drum or disk/drum. 1/2, 3/4 ton? My ‘55.2 3/4 ton uses a 1 1/8” stock. If you have stock brakes, I’d match OEM size. If you have disk/drum you’ll need a proportioning valve as well.

The Napa website shows specs including bore size on most of the master cylinders.

My plan is to stay drum/drum for now. I think the 1” might be the right one?

1/2 ton Stock is 1”, works well, look for corvette style non power brake m/c, bigger bore would be less pedal travel but requires more force to push…
Don’t know the quality but Speedway offers one with outlets on both sides, would have been handy…
Consider dot SS/teflon flex lines for all 3? Stiffens up pedal nicely and really not pricy….

Chuck

I’ve seen some kits that include residual valves. Is that necessary for drum/drum non power when using dual master?

I'm being told that the dual m/c sold by Brothers, Holley and POL part # MSTR900DRUM (built by CPP part # M-C118-L) has built in residual valves. It is also a 4 port GM m/c.

S2

residual pressure valves required if m/c below floor, IIRC 2 lb for disc, 10lb for drum, separate ones for front and rear on dual circuit m/c.
That Brothers M/C says “power only” listed in the features section, strange, was I looking at the correct one?

Where you get that info?

The part #s are on the box that I got from POL. After calling and speaking to each one(Brothers, Holley and POL) found out that (POL) Parts OnLine are the shippers for all three and CPP happens to be the manufacturer of the m/c.(?)

S2