I just bought a 2001 C5 vette with only 6500 miles on it. It is in MINT condition. Original owner has back problems and can't get in or out so she sold it. Its never even had a drop of rain on it. Its only had 1000 miles put on it in the last two years. Needless to say its spent a lot of time in the past two years just sitting in her garage. Anyway, I bought it two weeks ago, drove it for a week, put about 400 miles on it and then all of a sudden, out of nowhere, the front brakes locked up while I was on the highway. I pulled over, called AAA, and after about 1/2 hour of waiting for AAA, just for the hell of it, I started it up, backed it up about 10 ft and the brakes were free again and working fine. I drove it home. The next day I took it to Ron Tonkin Chevrolet here in Portland, OR. to have the brakes looked at. They looked at the fluid, the pads and rotors, the brake lines, etc. NOTHING WRONG. The service tech said he could find no reason for the lockup, to go and drive the car and just keep an eye on it. I left and over the next week drove it in all kinds of conditions from back country windy roads with a lot of high speed gas/brake/gas/brake driving to normal city driving. Everything was perfect until yesterday when all of sudden, again out of nowhere, the front brakes locked up, couldn't get the calipers to release. This is the FRONT brakes only. This time I had it towed on a flatbed back to Ron Tonkin Chevrolet. I just called them and talked to Brian, the service writer, and he told me the front brakes were back to normal and his brake expert can find nothing wrong.

What do I do now ???

Help or suggestions from someone who has had the same problem or is a trained brake technician would be much appreciated.

My direct e-mail is bigspif@comcast.net

Thanks,

Richard

 

very weird, have you tried flushing the brake fluid. I know they say nothing is wrong with it, but its cheap enough to flush out the old stuff. Also, not sure of this one, just throwing out the idea. Could it be the abs module doing something funky?

 

I think I understand what you are saying, but to be clear, do they not release after you use them, or they suddenly lock without you doing anything? Any information on the DIC?

Check the tech tips section on how to check codes and see if any sensor codes have been thrown.

The ONLY think I could ever think of that would cause the brakes to lock up like this would be the abs, but even that I don't quite understand... Otherwise I can't think of anything that woulc even impact that...

 

No, nothing on the DIC that I recall.

 

Chevrolet in Portland has got the car now. The techincian is suppose to get on it this afternoon. I will wait to hear what he finds. Is there a way to get CHEVROLET involved if he finds nothing ? Its out of warranty but its only 5 years old with just 7000 miles on it. I can't take it back from Ron Tonkin if they don't find anything wrong. There IS something wrong. What do I do if they don't find a problem ?

Thanks,

Richard

 

the worst part is that its hard to diagnose a problem when it doesnt happen when you want it to. Especially for a tech at a dealer or wherever, they cant just go replacing parts. As much as we would like them to, just cant happen. I think you will have to be patient on this one and see if anyone here has had the same or similar problem. g' Luck

 

Now you know why I'm not crying about my car not having the "Active Handling" option.

Check you DIC for codes (do a search here if you need instructions), tell us what you find.

If you do have a defective EBCM, there are several posts here with folks that have replaced it that can help as well.

My advice to you is the dealer will probably never "find anything wrong", and that this gal may (or may not I suppose) had knowledge of this issue, and now it's dumped in your lap. Good luck.

 

If both wheels are locking up, I would say the master cylinder is bad. If its just one, then probably just a caliper. Did it leave a skidmark? Did you feel or hear the ABS come on?

My tahoe had a bad caliper. You would hit the brakes and it would stick and start to pull to one side. It would get hotter and hotter causing the fluid to expand/boil and make the wheel lock up.

 

Hi,

Both front wheels lock up, no skid marks, didn't feel or hear the ABS system come on. Just all of a sudden, felt like you were driving with one foot on the gas and the other foot stomped down on the brake pedal. The pedal was locked down as well. No free play...hard as a brick.

Thanks

 

Whats an EBCM ?

 

Im thinking its the master cylinder.

 

No, it's the electronically controlled module that sits in front of the power steering pump, with the brake lines plumbed into it.

 

It doesn't sound likely that this could be your problem, since you say both front wheels are locking up, but here's what happened with my 85 C-30 pickup.

One of the front calipers would not release after applying the brakes. Turned out it was the rubber brake hose between the frame and the caliper. It looked fine on the outside, but had broken down on the inside. When you applied the brakes, the higher pressure would force it's way thru the line, but then when you let off, the line would close off and the lower pressure could not force its way thru and therefore the caliper would not release. I replaced the line and everything was great again.

I realize my truck is an antique and doesn't have ABS or Active Handling or anything like that, but just something to think about if you don't find anything else. Seems like quite a coincidence that both front lines would go bad at exactly the same time, but then you did say the car has been doing more sitting around than driving.

 

Had similar problem on a '93 Chev van, replaced rubber hose and all was well. If your car sat for 5 years, complete brake fluid FLUSH would be good maintenance anyway, cover the bases with a caliper rebuild/replacement, it should end your problem, (brake fluid has been known to change to GEL over time) this could cause a blockage after applying brake pressure and maintaining pressure in system causing pad application until is just subsides. If it doesn't work, you got big time worries.

 

The dealer found the problem. It was the power booster to the master brake system. Because the car has only 6000 miles on it, it spent too much time just sitting in her garage and the seals deteriorated. New power booster and all is well.

Thanks to you all for your suggestions

Happy Trails

 

I'm trying to understand how that would lock up the brakes. The only thing I can think of is after the brakes were applied, the seal could be hanging up the rod from returning. Did they explain how this caused the problem? Are you sure it's fixed? (Have you driven it enough to be sure it's not going to reoccur, since it seemed to be sporadic?)

Anyhow, I hope it is fixed for you. See, being a garage queen is not a good thing.

 

I tend to agree...

 

[QUOTE=bigspif]The dealer found the problem. It was the power booster to the master brake system. Because the car has only 6000 miles on it, it spent too much time just sitting in her garage and the seals deteriorated. New power booster and all is well.

I don't believe it. Seals deteriorate from foreign contamination or sunlight. Your seals are like new.

I've had a Dealer BS me on two items that I had apart and knew they were OK (E Brake and inop. pax window). I fixed both with adjustment. Dealer mechanics/Service Managers want to R&R, (remove and replace). Not many know how to troubleshoot and repair because time is money. To R&R is cheaper for them and charge you the flat rate plus all the parts.

Cheers, Curt

 

A brake fluid flush is still an appropriate maintenance operation for your car, to avoid problems later.