[mgarblik]

Sirrotica probably has the most likely answer. But a few things you can do to eliminate other items is: Items it can not be in your system. Master cylinder, power booster, flex hoses or hard lines. This is because the flex line is single in the rear and would effect both rear wheels. So the items left are the individual wheel brakes. Look for leaks of brake fluid or grease as mentioned . Smell the wheels when hot. Grease soaked linings will have a rotten burned sulfur smell. Burned brake fluid has a strong bitter smell. A 4-wheel inspection of the brakes should reveal the problem pretty quickly. If there are NO LEAKS brake fluid or grease, then the only thing left that could cause single wheel lock-up is uneven shoe to drum adjustment or extremely weak or a broken spring on the shoes. That is pretty rare. Let us know what you find.


I just re-read your opening post and caught the DOT 5 fluid mentioned. I know there are many people who swear by DOT 5 fluid in these old cars and have anecdotal evidence of decades of success using it in everything. If the fluid is DOT 5.1, that's fine. If your using DOT 5, pure silicone fluid, all bets are off as far as any and all rubber parts swelling, sticking, tearing in these old systems. This can be from the master cylinder to the wheel cylinder cups and everything in between. It's wonderful that DOT 5 fluid does not absorb water but it is absolutely not compatible with old rubber brake parts. I have personally seen wheel cylinder cups swell to double their normal size, master cylinder seals turn to jelly and roll off the piston, and antilock units seize up completely on modern cars. So in your case, with DOT 5 in the system for years, exercise each wheel cylinder with a little pry bar and make sure the 2 pistons feel the same and move smoothly on all 4 wheels and there are no leaks. The compatibility grouping for brake fluid is: DOT 3,4,5.1 all compatible and can be mixed. DOT 5 not compatible with any other fluid and must be evaluated on a case by case basis with the rubber product used. Good luck with it.