Brakes

[1952gary]

When I was driving the 52 B3B today the brake pedal become firm with the smell of hot brakes. When I stop for some time the pedal returns to normal. I adjusted the brakes as per the instructions about 3 days earlier and this was the first long drive since adjusting. What is causing this problem?

[B1B Keven]

Sounds like the master cylinder is hanging up.

[TodFitch]

Check for blockage in the tiny relief hole in the master cylinder.

[Young Ed]

Did you mess with the master cylinder pushrod? Not having enough pedal freeplay will cause issues.

[mechresto]

as your truck has no residual pressure valve, (or shouldn't) then clean the MC and reverse flush the lines up to the MC. "floaters" in the system can and will plug the fill hole and the small bleed hole in the MC. then recheck your brake setup making sure you have adequate clearance on the shoes, also adjust the MC pushrod to allow complete MC piston travel. too tight will cause the piston to not uncover the bleed hole in MC.

If I was to hazard a guess I'd say you're probably a little tight on the "heels" of your brake shoe adjustment.

Bryan

[Dan Babb]

In another car, I had a problem where the snap ring that held in the master cylinder piston wasn't allowing it to fully release. This slight pressure on the pads caused them to heat up. That would increase the pressure from the fluid heating up and it couldn't release back into the MC, so the brakes would engage. After it would cool down, they woudl feel normal.

Maybe your pedal isn't fully releasing AND you have the shoes a hair too tight, so they heat up after you drive for a short period of time. Then when the cool off, the pressure releases.

[Dave72dt]

Brake hoses can deteriorate internally as well. A portion will act as a one way valve and restrict fluid passage. Because it isn't a complete blockage, fluid will eventually seep past, allowing the brakes to release. Most likely the relief hole in the master. A broken or weak pedal return spring, free play adjustment should be l;ooked at as well.

[HanksB3B]

This sort of reminds me of a story back in my teen age days. I had a Volkswagon Bus and I knew my brakes needed fixing but I kept putting it off until a drunk old man in a cadillac stopped short in front of me without signaling for a left turn. I could'nt make the stop and nailed him. Funny thing was (oh yes my bus was custom by crash now alright) the cadillac folded in half just forward of the wheel wells. Looked like the Incredible Hulk grabbed either side of the trunk and gave one major push!

Ever since, I now consider a fully functioning brake system more important than a running engine.

Hank