I've spent some time thinking about this. I have a '51 4400 and a '52 6400 and neither one has decent brakes.

A rebuilt hydrovac is only a few hundred bucks and unless you intend to update the rest of the brake system, that's probably the easiest way to go.

The next choice is perhaps to purchase an under floor power booster kit, and instead of using a car type master cylinder use a dual master from a late 60's early 70's C-60 that would be dual and sized for a drum/drum truck.

You'll also need to run new brake lines, but replacing the brake lines on a 50-year-old truck is probably a good idea anyway.

On mine I think I'll update the entire brake system based on a P30 with a 12,000 lb GVW and disk brakes on the front.


1955 1st GMC Suburban | 1954 GMC 250 trailer puller project | 1954 GMC 250 Hydra-Matic | 1954 Chevy 3100 . 1947 Chevy COE | and more...
It's true. I really don't do anything but browse the Internet looking for trouble...