1962 Buick Electra 225 Brakes-Lock-UP

[Guest]

I own a 1962 Buick Electra 225 with a brake problem that has been around for some time now. When I depress the brakes hard, they lock up and do not release. I changed the master cylinder and the problem is still there. Someone told me it was the power brakes vacuum assist that causes the problem-but was also told this unit is not designed to be rebuilt and I cannot seem to locate a replacement. Any thoughts? Anyone have a similar problem? Thanks for the help.

[rocketraider]

Have you checked all the wheel cylinders and return springs to make sure they're working? And is it all four wheels locking or just one? Also a possibility a rubber brake hose has collapsed internally and isn't letting the fluid return to the master cylinder. Maybe some rust or crud built up in the steel lines?

I'd try flushing the whole system just to eliminate the hydraulics as a problem.

Then- even though it'll mean a hard stop with a heavy car- try disconnecting and plugging the booster vacuum source and then make the same kind of stop that locks the wheels. If it doesn't happen, then you know it's booster related.

I assume 1962 Buick uses the same Bendix or Moraine power boosters as Oldsmobile, and the 1961-2 Oldsmobile manuals have rebuild and troubleshooting procedures for both.

[Guest John Chapman]

You didn't say which wheels are locking. This symptom can also be caused by the brake flex lines failing internally. The lining collapses, trapping pressurized fluid in the wheel cylinders. Most frequently occuring on front wheels... but it can happen on the rears, too.

Good luck!

JMC

[Guest brh]

I agree check those shoes to see if they are not returning. Also you may want to consider new wheel hardware if those springs are old. I am assuming you are moving forward when they lock.