I’m finishing up the restoration of my 68 Hertz car. The problem I’m having is with the rear brakes. The entire system is new. Everything was changed out except the proportioning valve and the distribution block. I got a kit for them from WCCC and installed it.
With the car on stands and with the engine running and the car in gear at idle the rear wheels won’t stop turning with the brakes applied. The brakes have been bled, no air. Talked to Don at WCCC and he thought it was the proportioning valve. talked with a shop that I have been dealing with for 25 years and they thought the same thing. Soooo, I ordered a NEW proportioning valve and installed it and still the same problem. No back brakes. The power booster checks out good, the rod in the booster is adjusted to shop manual specs. Any sugesstions?!
Pull the drums off and make sure the shoes & hardware were installed correctly. Make sure the self adjusters are working and it might just be a case of the shoes not being adjust up tight enough to the drum. You can also watch the wheel cylinders while someone pushes on the brake peddle to see if they are extending. if not, then the problem is further up the system ie: air in lines, proportioning valve, master cyl.
When you say “bled” did this include bench bleeding the master cylinder?
Master cylinder was bench bled and all wheels were bled. Rear brakes etc back there are installed correctly. Wouldn’t hurt to double check everything again.
Pull the drums as suggested and see if you get any movement. Did you replace the rear steel brake line? They tend to rust from the inside out and can be rusted solid inside.
Yeah, that’s my next step. pulling the drums. All the lines like everything else in the brake system was replaced. Going to go over everything again just to make sure I’m not over looking something.