The brake pedal seems to get harder and harder to push. The brake lights stay on even after I turn it off. Normal juice brakes no vacuum assist.

How to I check the master to see if that is the problem or do I start at the wheels. When I drove it all seemed fine. I have no idea where to begin or how to check the different parts. Any help would be appreciated. Thanks Dave S

 

Any idea how long it has been since any work has been done on the brake system?

 

Everything was done within the last year or so. Engine, trans, wiring, clutch and brakes. Suppose to be a rebuilt master and wheel cylinders. It has about 300 miles on it and I just purchased it a few weeks ago.

 

If you crack a bleeder valve do you get a spurt of brake fluid out of it under pressure ?

 

I have not tried anything but will see if I do. If yes I assume that means the master is not releasing properly. What do I do then?
Does it matter which wheel I try it at?

 

Are they all original type components , or have the brakes been upgraded with disc brakes and a different type master cyl ?

 

All original type just relined shoes and rebuilt master/wheel cylinders

 

Make sure the M/C pushrod is clear of the piston with no pressure on the pedal.

 

If it has a pressure switch at the master cylinder and the brake lights stay on without pressing on the pedal you either have a master cylinder problem or a linkage problem between the pedal and the master. Releasing hydraulic pressure won't tell you where the problem is. Either remove the master from the frame or remove the pin that pushes into the back of the master. While removing either you should be able to figure out the problem.

 

Thanks guys. Have to get it up on stands to get to master. Will let you know what I find. Dls

 

It has finally warmed up enough to work on the brakes. I hooked the battery up and the brake lights did not go on. The pedal is not as hard to push as after driving it (dummy that I am I did not check to see if a wheel was hot when I put it in the garage after driving and noticing the lights) I jacked up the rear end and spun the wheels. The right rear seems to be draging a little. Before I pull a wheel cylinder or the master could a badly adjusted shoe cause the pedal to be hard to push and make the lights stay on if they were hot? Did I mention I really hate bleeding brakes?

 

Tried all of the suggestions offered so far. Still have a problem - so I think it might be the brake line is too close to the exhaust and the fluid is heating up and expanding. Is this even possible as a consideration or am I grasping at straws ?????

 

If the brake fluid was getting hot enough to expand (and providing the master was overfull and sealed extremely well) all the brakes would apply (or drag a lot) and the truck would be difficult to move.

Originally you stated the pedal was getting harder and harder to push and the brake lights were staying on. If the pedal was becoming harder to push in order to provide the same amount of stopping power that means something is inhibiting the shoes from pressing against the drums. Since the brake lights are staying on after your foot is off the pedal I'd have to guess that there's something in the pedal to master cylinder area causing issues. You see, binding pedal linkage would make the pedal harder to press and build pressure and when your foot is removed the same binding is causing the pedal to not release the hydraulic pressure in the brake light switch. The master cylinder could also be the cause but I've never seen one act like this in over 45 years. Not saying it couldn't happen but it would be odd.

 

What about the flexible brake lines? Are they the right ones?

 

I thought it may have been the petal binding but it is not touching anything but where it connects to the master. If I let it cool off for an hour the pedal is back to normal and the lights go off. I can sit in the garage and pump the brake a hundred times an no problem. Drive it for twenty to thirty minutes and it gets hard to push and the right rear wheel is hot. None of the other wheels are heated up like that one. It just makes no sense to me and two guys that have worked on old trucks/cars for a long time.