Anyone ever run into a situation where the brake system will not release the pressure to the front brakes? Basically the front brakes continue to clamp down on the rotors till smoke comes from the wheels. This is after driving and making a few stops. If I let it sit for awhile it seems to release the pressure and will drive OK. Is there some sort of valve in the master cylinder that could be stuck?

If anyone has run across this let me know. Also it seems like the rear brakes are getting no pressure.

So the calipers and wheel cylinders, pads and mastercylinder are all new....

I'm perplexed...

Might be worth getting a used one from
Gary at Petroworks, he should have plenty
available

Hello,

sounds like the hose is bad,this has happened  to  me.hose's go bad and thats what happens.Sometimes they leak,sometimes they  stick.But you say both frt wheels....Might  be the valve.

Later  TomK.

You need more free play on the master cylinder, adjust the push rod or grind it down some untill you get some play in it.

WAS THE PROBLEM THERE BEFORE THE NEW PARTS WENT ON?IF NOT THEN CHECK YOUR WORK.

You need more free play on the master cylinder, adjust the push rod or grind it down some untill you get some play in it.

Hmm now this makes sense.  So what your saying is the push rod is too long and not returning to it's designed location thus not releaseing the valve and the fluid in the line... Now that makes sense.

To answer the question this problem has followed me through into the new parts.

What about a clogged rear line. The back brakes do not seem to work. Could the back brakes being clogged effect the front brakes?

What year is the Trucklet ?

Do you have a LSPV ?
(load sencing proportioning Valve)

might be the proportioning valve , or a slider.  stan

If the master cyl. does not come back all the way it will not let fluid into the rear brake part of the master cyl. open the lid on say an older chevy master and look in the bottom of it you will see a small hole in each of the resiviors, if the cup does not go back past it it will not let new fluid drop in the hole,the front resivior is for the rear brakes and the rear is for the front brakes, there is a spring on some between the cups for the rear brakes and this must be compressed allready.

It little green men!!

     lol any way i hate thoes little nomes that run away with parts and goblins tha move into new ones!!!

 ok well it sounds like the proportioning valve to me, there is an artical a while back that tells how to tell if your rig has one---  is the vehicle equiped with ABS - if it is it could be a faulty sensor or valve on the abs controler. 

have you Blead the breaks? are the back lines full of air?

This happened to the rockstar. The master was bad. Ive seen it happen to a few other older modlels too. Dont adjust the push rod. There is no reason that it should ever go out of adjustment once set. im quite certain its the master cylinder.

Mike

that's what I am thinking... Mastercylinder.. I will let you guys know what I find.. this is the second mastercylinder this truck has eaten. So either it's two bum units or there is something else very wrong.

I took it to a shop cause it's a 60 miles or so from home and they cracked the bleeder valve and the pressur released. Drove it for a bit and they locked up after multiple stops. they then cracked the line at the master cylinder and again the pressure released and it drove fine...

so to solve the problem I sold the truck and bought a 4 door 16 valve!

so to solve the problem I sold the truck and bought a 4 door 16 valve!

That's one way to deal with it. 

I had the same thing happen to my 4 door 16v, was driving along on a main road, and it started slowing down, shifted down a gear, and still, in the end i was in first and i pulled over, got out and saw loads of smoke coming outa the front breaks!!! i left it for a while, and went to try move it, but i couldn't cos they were still locked, i couldn;t even get it to move in 4wd Low. n the end i had to take it to the dealer, and we had to change the master cylinder cos the valve inside were messed