How Do I Reset the Proportioning Valve ?
 

I guess I lost my rear brakes a short while ago, as the result from a bad wheel cylinder. I knew that I needed new shoes, wheel at some point I broke a front brake line and the master cylinder went dry . NO BRAKES !!! not fun. OK I replaced all of the brake lines the bad wheel cylinder and the shoes. I benched bleed the master cylinder first next I bleed the front brakes and now I'm not getting any fluid out the back. A friend of mine told me I need to reset the check valve inside the proportioning valve. I can not figure this out, I need some help.

Re: Resetting Proportioning Valve
 

I should of added this is on a 67 C-20.

Re: Resetting Proportioning Valve
 

ttt

Re: Resetting Proportioning Valve
 

It's basically a pressure balancing switch, so you need to relieve the pressure on the side that has more.
Open a bleeder on the higher pressured side and push te pedal down until it gets to the floor, it may "click" at that point. It's not always that easy,but it can happen.
If not, close that bleader and "slam" the brake pedal. It's mostly about "speed", hit it quickly,but forcefully. You will not "feel" it with this method though, you will have to check.

Re: Resetting Proportioning Valve
 

if you have the original drum brakes you do not have a proportoioning valve but a distribution block

Re: Resetting Proportioning Valve
 

^ Correct.

Did you also replace the rear brake line hose?

If you have the drums and you're not getting fluid to the back brakes then either the part of the master cylinder that controls the rear is defective or you have a blockage to the rear brakes.

I'd start by loosening the connectors starting at the master cylinder while having someone apply the brakes to see if you have fluid there and work backwards. And if you replaced the master cylinder, new ones are not what they used to be.

Re: Resetting Proportioning Valve
 

So to reset a distribution block is it the same as a proportioning valve ?

Re: Resetting Proportioning Valve
 

There is nothing to reset on a distribution block. Be sure to check the rubber lines. They will swell with age and eventually block off the flow of fluid.