Brakes locking up 1971 LT-1

[Ted K.]

Vette has been sitting for about 2 years since brakes were rebuilt, by previous owner. Got car running today and drove it around the block. When I started out I had about half pedal before I got halfway around the block the pedal was all the way up and firm. When I got back they were almost locked up and smelling hot.
Any ideas.
Ted

[Joe L.]

Re: Brakes locking up 1971 LT-1

Vette has been sitting for about 2 years since brakes were rebuilt, by previous owner. Got car running today and drove it around the block. When I started out I had about half pedal before I got halfway around the block the pedal was all the way up and firm. When I got back they were almost locked up and smelling hot.
Any ideas.
Ted

Ted-----


The first thing I'd suspect is deteriorated rubber brake lines (INTERNAL deterioration). The next thing I'd suspect would be a defective master cylinder.

[Robert S.]

Re: Brakes locking up 1971 LT-1

I have had this same problem on my 74' twice. Car has power brakes but I am not sure that matters. The first time right after I bought it and the second time last summer when it had not been driven for a while. In both cases I was able to free the brakes by repeatedly stepping on the brake petal. I attributed the problem to rust build up in the master cylinder but I cannot prove that. After the first event I cleaned and replaced the fluid in the master clinder but did nothing after the second event. Once they were freed up the brakes worked fine. I still plan to eventually rebuild the master cylinder.
My son also has a 74'. He experienced the issue of collapse of the rubber brake hoses mentioned in the previous post. In his case it led to uneven braking (but not lock up) and came on suddenly and was unsafe. We could not see any external signs of problems with the rubber hoses but after they were changed the problem went away. If you have any of the original rubber hoses on your car, you may want to change them out as a precaution.

[Bill M.]

Re: Brakes locking up 1971 LT-1

Get them hot again and check the rotors. If all hot, it's probably the master. Don't just touch the rotors...lick your finger and listen for the sizzle (hard lesson learned). I had a plugged compensating port in the master that locked all 4 rotors.

[Jim T.]

Re: Brakes locking up 1971 LT-1

Ted when your brakes were rebuilt about two years ago what was done?
If your 71 still has the original rubber hoses to the calipers they could break down internally on the inside and prevent applied fluid pressure from releasing to the calipers.
Had this happen to my right front 68 about 20 years ago. It got my attention by smoking, thinking the right front was on fire. Let it cool, the 68 seemed to roll okay and got home gearing down and hardly any use of the brakes. The emergency brake does help.
New hoses are easy to replace as well as rebuilding the master cylinder.
Master cylinders are less expensive than rebuild kits at auto parts stores, but you will not have the original master cylinder.

[James G.]

Re: Brakes locking up 1971 LT-1

Ted, I know quite a few guys not only with Corvettes that have had the pistons freeze up in the caliper when the car was not used for a while. My car has s.s. sleeves in the calipers, and I used silicon fluid when I did my brakes so far there has been no trouble.

[Gary R.]

Re: Brakes locking up 1971 LT-1

Ted, I know quite a few guys not only with Corvettes that have had the pistons freeze up in the caliper when the car was not used for a while. My car has s.s. sleeves in the calipers, and I used silicon fluid when I did my brakes so far there has been no trouble.

Correct if using DOT3 BF and letting the car sit for years will cause the pistons to lock up- SS lined or not. Had to repair a couple because of this. The BF was muddy. Also has mentioned the rubber hoses should be replaced if older.

[Ted K.]

Re: Brakes locking up 1971 LT-1

Thanks for all the info. Based on my symptoms and everyone's suggestions I believe my problem is with the master cylinder not releasing the pressure. That will be my first project. Will let you what I find.
Ted