The Stovebolt Site Forums The Shop Area General Truck Talk 1954 chevy truck brakes

I have a question about something strange my brakes did yesterday. Okay first of all the truck was just finished last summer, a complete frame off restoration. So all of the brake lines are new, along with new wheel cylinders and a new dual chamber master cylinder with power boost. The only upgrade is the addition to power brakes, other than that it is all stock including drums all the way around. Okay so after the truck had been sitting all winter, I decided to fire it up and pull it outside to let it run a bit. While I was pulling it out I hit the brakes really hard on accident and brakes locked up. Now I don't mean completely but there was still pressure at the wheel cylinders like they weren't releasing all the way. So I pulled the truck back in and jacked it up. The wheels were hard to turn. I cracked a bleed valve on the front and the pressure released, I also did the same on the back. So after releasing the pressure I tried them again and it was like it never happened. I hit them hard and they did not lock up. They were perfectly normal after that. Good pedal and stops fine. So could that be from sitting for months without driving?? It was really strange and I'm not sure if I should be concerned or not. Thanks guys.

Did all of the wheels get tight? If so, it would likely be the master cylinder. Could be out of adjustment or bad from the factory.
Carl

Yes it was all the wheels. They all seem to be fine now, just kid of weird.

Hy nak1954, I think what may have happened is the master cylinder never returned to its fully at rest position. Probably because the brake pedal linkage was a little dry and stiff after the trucks long rest period, using the brakes a couple of times freed up the stiffness and let function return to "normal", hope that helps.

Well the brakes are holding pressure all the way around again so I am leaning towards the master cylinder being bad. I don't think it would have anything to do with the booster but any other suggestions would be great. thanks

I mean correct me if I'm wrong but, there should be no pressure at the wheel cylinders when the pedal is not pressed down correct?? The brakes are drum all the way around.

There is a small amount of pressure on drum brakes when the master cyl. is not depressed. It is called residual pressure & is built in to keep from drawing in air on release of the brakes. If it enough to cause drag , you probably have a poor adjustment in the rod between the booster & master cyl.

I will have to check that, I didn't know that rod was adjustable. I thought the only adjustable rod was the one that goes from the booster to the brake pedal. I suppose if I unbolt the master from the booster and I hear the brakes release all the way, that is my issue. Thanks I will keep you posted.

Check your toeboard clearance on your brake pedal. If it's not set right the rod won't completely retract from the master and won't release the pressure on your brake system. Shop manual will give you the correct measurement for your truck. Worth a look.

Read your initial post again and I'm probably wrong. Was thinking about how the stock setup works. Probably ought to learn to read one of these days.