MY friend has a 1941 Plymouth he just bought. It had been sitting for a long time. We've got it to the running and driving state but now we're having a problem with the brakes. Intermittently the brakes will gradually start to drag/ lock up. The first time it happened we came back after some lunch and the car wouldn't move. When this happens it seems like all four wheels are locking up and the brake light will stay on. The first time we just left it and eventually a couple hours later it was fine again and didn't act up for a few more days. He's pulled the master twice and dis***embled it and cleaned it. We've bled it everytime afterwards and have good clean fluid. He just tried dis***embling it again this monday and it was fine until last night when it started to lock up again. He'd heard the "relief port" in the master could get plugged with debris causing this but it seems like everything is clean. Everything on the brakes is currently stock and operating fine with the exception of this issue. Has anyone seen this before and have a solution? Or can anyone suggest an updated master to install in place of this one? Thanks, Jay (and Pat)
Those brakes are the worst thing I think Mopar ever did. They are a pain to work on and to keep adjusted. ECI makes a bracket for converting to a late model master cylinder. I make a disc brake conversion if you go that route, www.rustyhope.com.
Also can anyone tell me if the master cylinder in this car has two internal port holes? We can only see the one.
There is a tiny vent hole in the cylinder. When it's clogged, you get symtoms like you're describing due to pressure building up in the lines. Clear the hole with a needle or wire and I bet your problem is solved. Sometimes it's a real pain to clear the hole if it's really rusty.
Thanks. We pulled the master for the third time tonight and sure enough there was a second tiny hole in the master cylinder. It took a pretty close inspection to discover it. It was plugged up pretty solidly. We used a paper clip to clean it out and then a small drill bit also. I'm pretty confident we've got it this time! Thanks for all the help! Jay
Viva la HAMB. just saved my *** on the 41 i just picked up. same deal, stranded my *** at school monday!
I am Alienbabys friend and I ended up converting it to dual chamber master, I still had the problem after cleaning the two holes, I am sure I could have rebuilt the master and it would have been fine but I figured it was just safer to go with the the dual anyway. Thanks for all the help guys.
Once you got a clean master, keep it that way. Even if it means undoing every line from the wheel cylinders, blow out the whole system with compressed air (nitrogen is better), rebuild the wheel cylinders then re***emble and flush the whole works with clean fresh brake fluid. This should keep you going. Bob
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