The Stovebolt Site Forums The Parking Lot Tons 'o Fun power brake booster question

I'm ready to change the manual brakes to power with an after market brake booster/master cylinder kit, all i can find are 1/2 and 3/4 ton kits, i have a 59 3800, do all 54-59 3/4 and ton trucks have the same stock brake master cylinders? If so a 3/4 ton after market booster/master cylinder should fit. The kits use 7" boosters with corvette master cylinders. Also does anyone know what the stock size is of the wheel cylinders on the front and back wheels? And are the brake shoe's the same size on the front and back? I have been having a hard time finding these parts at the local flaps so any part numbers would really help

Hy Panman, a lot of the parts are the same between the 3/4 ton and 1 ton brake systems, some one tons have 12" front and rear brakes, and some have 12" front and 14" rear brakes, both have 1 1/8" master cylinders. Corvette master cylinders are for disc/disc applications, so you will need 10 p.s.i. residual pressure valves for each of your drum brake circuits. In short the systems designed for a 3/4 ton truck should work, but I would not go smaller than a 1 1/8" bore master cylinder, hope that helps.

Ok 3B i got it , but what would happen if i used a 1" bore master cylinder?? I restored a 57 buick roadmaster with oem power brakes and it had a 1" bore master, more weight, bigger motor, but smaller brakes, it stopped ok, all of the brake kits i have found say that they are made for 1/2-3/4 ton with disc/disc drum/drum or disc/drum setup, do you know what year truck master cylinders have 1 1/8 bore in them that i can use instead of the corvette one?? I have a good 1982 c-10 master cylinder layin on the garage floor right now, or would one from a ton truck from the 70s or 80s work? I'm ready to get started on this step of my project, but i don't know what will work

Hy panman, according to my brake book there are four different possibilities for master cylinders for a 1982 C10, all of them have a bore of 1.125" or larger so they would work. A few years ago I did a conversion for a guy from single system to dual, his one ton had the 14" rear drums, he did all the research I just did the install. He has toured the truck around North America with no problems. I'm not an engineer, just a mechanic, and I don't second guess an engineers design, unless that design keeps failing, that's why I suggest not going smaller than the original master cylinders bore, hope that helps.

I'm no engineer, but I think the smaller the bore, the longer the pedal travel will be. If your wheel cylinders are big,your MC needs the capacity to match or you might run out of pedal in an emergency stop. Residual pressure valves are a must in my opinion.

Thanks for the help, i guess i need to dive into the wheels and check to see what size the drums are and the wheel cylinders, i don't have e brakes anymore now that i have changed trannys so real good brakes are a must. i will have to check into the residual pressure valves