Front Brake locks up

[GaVair]

First time posting. I have two vairs 66 140 conv. and 67 4 dr (Grandfathers old car).
I am having a problem with my front right brake locking up. I took the car out and drove it about 2 miles when the front brake seized up. I had to cool it down (lots of water) pull the drum off and back off on the adj. Got home and replaced both front brake cylinders. Took it out again and got about 5 miles and the same thing happened. No recent brake work.
Appreciate any advice.

[Motornoggin]

It might be the rubber brake hose. They deteriorate from the inside out and can swell and not let the pressure bleed off.

[GaVair]

I had already relaced the brake lines about 3 yrs ago. Sorry, by recent I meant that I had not done anything recently before the problem started.

[UNSAFE]

It really does sound like a bad brake hose . If you don't want to buy a new one you might try swapping them left to right to see if the problem changes sides.

When the inside of the brake hose starts seperating it acts like a check valve . It will let pedal pressure get thru to operate the brake but it won't let the relief pressure back out.

Another cause could be not enough slack at the plunger rod to the master cylinder . If it is to tight it won't let the return ports open. This is unlikely if it was working before and you didn't mess with the master cylinder rod.

I'd bet a cold beer that it's a collasped hose . It may look perfect on the outside and still be delaminating inside.

This exact thing happened on a back brake on my Vette . I ended up cutting up the old hose into short pieces and found the bad part only was only a little over an inch long. Here's a poor pic of it.

[GaVair]

Wow, did not think a brake line could fail that soon. I will chase that one tomorrow. I will post results. Thanks.

[GaVair]

OK, update and new issue. I tracked down the lock up issue to the master cylinder, the piston was not returning fully. Replaced cylinder ($18 at AutoZone) and problem solved.

A very old issue is still there however. The same (right front) brake grabs VERY hard and pulls WAY to the right when the brakes are used. This has been an issue since I got the car. With new cylinders, lines and shoes I am at a bit of a loss of what to look for next.
Any suggestions would be greatly appreciated.

[UNSAFE]

The same (right front) brake grabs VERY hard and pulls WAY to the right when the brakes are used

Often it's not the brake that feels like it is pulling but rather the other side not doing enough .

I'm assuming that you have adjusted the star adjusters so that both sides are about the same ?

You have done cylinders so that's likely not the problem.

You could have something loose in the steering but you'd notice that as sloppy steering.

Even tho you found the cause of the dragging brake the hose could still be at fault but we'll call that unlikely.

What does that leave ? Surface area . You may have a problem with the drum or the brake shoes. If your drums have been turned on a brake lathe they may have too big of a diameter for the shoes. In the old days the shoes were arced to match the drums . This meant that some of the shoe was ground down so that the OD of the shoe matched the ID of the drum.

If the drum is too big only a small part of the friction material on the shoe will be making contact with the drum and the braking will be drastically reduced.

This is another case where just swapping the drums left to right might pinpoint the problem.

[GaVair]

Sounds like a good idea. Will switch them over.
I did panic stops in reverse and it did not pull. Not sure if it means anything, just another piece of the puzzle.

[reidmier]

Remember that the back brakes actually do something on a Corvair. If they're out of adjustment, they'll cause the car to pull pretty hard too. When I adjust mine, I tighten them down with the star wheels until I can barely turn the drums by hand and then lift the adjuster with a small screwdriver and back the star wheels off about 8 clicks. This seems to be just about right. Since the self-adjusters don't always keep everything the same, I adjust them the same way again every time I do an oil change. Hope you figure it out.