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Brake seized 2 times in 2 months

I drive a 1999 Mercury Villager. Friday, the front driver’s side brake locked up for the second time in two months.

The first time it happened (on Thanksgiving Day), I had slammed on my brakes to avoid hitting a car that turned left in front of me (against the light). To my knowledge, this is the first time the ABS had ever kicked in during the 18 months that we’ve owned the vehicle. Immediately I felt a problem with the brakes as I continued driving home. My husband couldn?t find the problem right away, so the next day, we drove the van again for a few miles. There was an obvious odor, and we realized that we were smelling the brake pad burning up. When we returned home, the disc was so hot it was glowing bright red! My husband valiantly attempted to fix the problem. Thinking the root of the problem was a stuck caliper, he replaced the front driver?s side caliper, the brake pads, and had both front rotors turned. That did not fix the problem. We took the van to our mechanic. Initial diagnosis was a clogged brake line hose. The hose was replaced, that did not fix the problem. Second diagnosis ? faulty proportioning valve. They replaced the proportioning valve and master cylinder. That fixed the problem, until this past Friday.

On Friday, I was driving down an icy hill approaching an intersection. The van started to slide on the ice, and the ABS kicked in. I let my foot off the brake, then slowly depressed it again while steering onto the snowy shoulder where I had better traction. I stopped easily, without having to apply stronger than usual force on the brake. Nothing seemed amiss until the next morning. There was no change in the feel of the van while driving, but I started to notice the smell of hot brake pads. I drove probably 5 miles home, where I confirmed that the front driver?s wheel was hot. The van has remained in our driveway, and we plan to take it back to the mechanic who worked on it last time.

Does anyone have any insight or suggestions about what could be wrong? Could the ABS somehow be causing that brake to seize up? Both times this happened the temperatures were below freezing. Could that be a factor? Any help would be appreciated!

Unfortunately, the only thing left on the brake system than is not new is the ABS module. The fact that the problem occurred both times after the ABS kicked in leads to this module having an internal problem. These are supposed to be fail-safe devices, meaning that if it were to fail, it should not interfere with normal braking. However, yours may be a rare condition where it is preventing the pressure from being released. It will probably need to be replaced, and it will be pricey.

I was afraid of that. Is it an option (at least temporarily) to disable the ABS? This is actually the first car we’ve owned that has ABS, so we are used to driving vehicles without it. I know it is a safety feature, but I also know it is not absolutely essential. If a vehicle has ABS installed, is it possible and safe to drive with it turned off/unplugged. We’ve spent so much on repairs lately (between this van and our work truck), we really can’t afford to pay a hefty price again so soon.

I had the same problem on a 1990 Ford Aerostar. This minivan had antilock brakes only on the rear wheels, and the rear brakes would lock up if the antilock brakes came on. The Ford dealer’s service department was unable to find the problem even when I locked up the brakes and blocked their service entrance. A good independent shop finally found the trouble with the antilcok braking system–some valve was gummed up. This took care of the problem.

There may be “stuff” in the brake lines. You want to be sure that the brake lines are clear----all of them. The brake master should be emptied (why not again, is brake fluid that expensive?). And, refilled. Remove all four brake bleeder screws, one at a time. bleed the brake fluid until clean, new, brake fluid comes out of each bleeder hole. While the brake fluid is streaming from the bleeder screw hole, observe that it is coming out in a free-flowing stream (during each stroke of the brake pedal.
Since the brake got very hot, again, the heat could have damaged the new caliper piston seal. This could, not necessarily is, cause for the caliper piston to freeze.
What does “the ABS kicked in” mean? I don’t understand.

Here is some information on what the ABS is, and what it does. Click on an image (drawing) for enlargement. Click the maximize square for a full page image. http://www.autozone.com/shopping/repairGuide.htm?pageId=0900c152800921ac
Some, otherwise good, mechanics don’t know beans about checking electrical, or electronic, systems.
The ABS (Anti-lock Brake System) has both, electrical and electronic, components. If you get a snow job, on this point, remember: it is January.
The wheel sensors should be checked for operation. If a sensor isn’t talking to the control computer, or is incorrect, the computer may not know that the wheel has stopped rotating (locked up), and, thus, doesn’t reduce brake fluid pressure to that wheel.
There are trouble code readouts (using a scan tool) for problems with the signals reaching the control computer. If the ABS light is on, it’s telling you, “Hey, I got something I want to tell you about so-and-so”. It needs to be “listened” to (with a scan tool).

Thanks.
The ABS light has never come on. Does that indicate a lower likelihood that it is an electronic/electrical problem?
I will be sure our mechanic has checked the wheel sensors, and ask about their familiarity with these types of electric/electronic systems.

Thanks for the detailed suggestions.
By “ABS kicked in” I just mean that I felt what I assumed to be the anti-lock brake system operating. When the wheel(s) started to lock up when braking, it felt like the brakes sort of pulsed very rapidly, with no input from my foot! From my limited knowledge of the purpose and function of ABS, I assumed that what I felt was the system doing what it was supposed to do. Although, as I thought about it while answering your question, I am wondering if what I felt was more of a malfunction rather than normal operation. I’d say the second time this happened, it felt more like jerking than pulsing. So perhaps the caliper locked up before I ever even came to a stop? However, there was no jerking sensation (or any other change in the feel of braking) after I came to a stop.

When I had the problem I described in an earlier post with my 1990 Ford Aerostar, the ABS light never came on. I had all kinds of fixes from the dealer–new brake hose, one new brake line. When the dealer’s solution was that the brake linings were not “genuine Ford parts” on the back wheels and causing the problem, I went elsewhere. We have a wonderful tire store in our town that also does mechanical work. I took the brake technician for a quick ride in the parking lot–locked up the rear wheels for him with the antilock brakes and he knew immediately what the problem was. I don’t remember the name of the valve, but he cleaned it and flushed the brake lines and I had no more problems.

Thanks for the input!
The van has been dropped of with the mechanic, but I don’t know what was discussed. I haven’t heard any updates yet. I will mention the gunky-valve possibility, and flushing all the brake lines. I think that I sort of assumed that when they replaced the master cylinder, they would have flushed the whole system and put in new fluid. But I didn’t think to ask at that time. We’ll be sure to check on that this time.