Brake upgrade

[Rugby_7]

Is a 3/4 ton brake booster and Master cylinder really an upgrade for a 1975 k5? From the info on Rockauto it seems that the booster is the same part number as 1/2 ton. Also I think I've read that the 3/4 and 1/2 ton master cylinders front and rear brakes are opposite?

 

[Rugby_7]

Forgot to add that I am switching to 3/4 ton axles with a 14 bolt disc brake swap. I put in new brake lines from inline tube with their disc brake prop valve

 

[JoshHefnerX]

It's about balance. If you're upping the piston area on the disks you need to up the piston area in the mastercyl. If you don't you'll probably have excessive pedal travel. The booster may not be any different, most of the time the boost is determined by the diameter of the booster. I will say if you're going to go to a MC newer than 1980 you'll need to go w/ a newer booster as there was a change in the MC snout bore. I swapped mine out to a newer model and found that I was able to bolt on one from an 81 to get the larger mc bore hole. Got more info in my build thread.

 

[Rugby_7]

It's about balance. If you're upping the piston area on the disks you need to up the piston area in the mastercyl. If you don't you'll probably have excessive pedal travel. The booster may not be any different, most of the time the boost is determined by the diameter of the booster. I will say if you're going to go to a MC newer than 1980 you'll need to go w/ a newer booster as there was a change in the MC snout bore. I swapped mine out to a newer model and found that I was able to bolt on one from an 81 to get the larger mc bore hole. Got more info in my build thread.

Thanks! ill check that out!

 

[campfire]

I don't know about the booster, but IIRC there are 2 different 3/4 ton brake systems (with different RPOs) depending on GVWR. Check with @82355, he would remember the details.

 

[nutt7]

Disc brakes require more fluid to operate properly. A disc-disc master would be ideal with your new prop valve. Read into joshhefnerx solution. I did hydroboost so if you're still vacuum, the method I used won't work.