Brake trouble
 

So I have been struggling with my new truck for a while, if ever I have to make a quick stop or God forbid it's raining when I stab the brakes the backs instantly lock up! Does anyone know where to start, I would like the front and back to be equal. The truck is a 71 Custom Camper 20
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Re: Brake trouble
 

You might have gotten some brake fluid on the pads. Or grease. Pull the drums and look for a wheel cylinder leaking.

Re: Brake trouble
 

I think Geezer is right, I had this problem many times with rear drive patrol cars (caprice) and it was always a leaking axle seal somewhere.

Paul
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Re: Brake trouble
 

Thanks for the input I will start there and keep you updated
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Re: Brake trouble
 

Sounds like the proportioning valve.

Re: Brake trouble
 

DT1 that was my first thought maybe because it isn't one wheel it's both. So is the valve adjustable or do I need to buy a new one? If so do I buy an exact replacement or something else?
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Re: Brake trouble
 

You should still check to make sure that you don't have a leaking wheel cylinder.
Even a small leak in one of them can compromise the rear system and cause both to lock up in a panic stop.
Also, make sure your brake indicator light is hooked up and working. If you're NOT getting an indicator at the dash the valve is probably adjusted right.
If you are getting a light, you will have to bleed the system to re-center the pin until the light goes out.

You can also install an aftermarket, adjustable valve that you can dial in to suit your preference.

Re: Brake trouble
 

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I am rebuilding the brakes on my C-20 right now. The right rear wheel cylinder is leaking and both axle seals appear to be leaking. The front shoes were worn down to the rivets and the rears were worn through the shoes and into the metal backing... I will be replacing all of the above. I have been getting my parts at my local NAPA Store. They also turned my brake drums for me. So far so good.

LockDoc