If brakes fail once, they might fail againg. Back to the dealer!

Dear Car Talk

Dear Car Talk | Dec 01, 2004

Dear Tom and Ray:

You guys really make me laugh. So now you know that one other person is out there laughing with you! I have a 2003 Windstar with about 16K miles. Last Saturday, my wife took my car to watch the Mummers parade in North Wildwood, N.J. As she approached a stop sign, the brakes failed her. The pedal went to the floor. She was not going very fast and was able to bring the car to a stop without hitting anything. She immediately turned the car off, and the brakes returned (the pedal returned to its normal position and the brakes worked). The brakes have been working normally ever since. I checked under the hood, saw no leaks, and the master-cylinder reservoir was full. The brake pads look good. We took it to a Ford dealership (they kept it for a day), and the mechanic said that the brakes were OK, that he made an adjustment in the hydraulics. Tom and Ray, now I have lost confidence in the brakes. Any suggestions? Should I expect failure again? Should I trade it in? Could it be a bad master cylinder or anti-lock-brake system? How can I ever have confidence in the brakes again? -- Gene

TOM: You can't, Gene. At least not until somebody gives you a credible explanation for why they failed. No one has done that yet.

RAY: There is no "adjustment" you can make to the hydraulics, so he was just trying to get rid of you with that one.

TOM: I can think of a few possible explanations for what happened. The most likely is that your wife accidentally drove all the way to the Mummers parade with the parking brake applied -- or, more likely, partially applied. That would mean that the brakes were being applied the whole time she was driving, even though her foot wasn't on the brake pedal. That overheated the brakes, which boiled the brake fluid, which led to the brake failure.

RAY: Then, when she shut off the engine and let things cool down, the brakes returned to normal. And we would assume that after that, she released the parking brake.

TOM: How do you prove that's what happened? I guess you have to put her under the klieg lights and interrogate her.

RAY: Actually, you might do better just asking her whether it's possible. You said it was your car she was driving, and this is something any person can easily do in an unfamiliar vehicle. In fact, I recently drove halfway to Montreal with the parking brake partially applied in one of our brand-new test cars. I won't mention whose car it was, because I don't want Chrysler on our case again!

TOM: A related cause of intermittent brake failure is a faulty power-brake booster. That creates a situation similar to leaving the parking brake on. It fails to release the brakes entirely. So, it also causes brake failure by overheating the brake fluid. If that's the case, it could happen again.

RAY: If it's not either of those, then it's probably a bad master cylinder, which would need to be replaced.

TOM: So, unless your wife fesses up to perhaps having seen the red "parking brake" light on when she was driving that day, take the Windstar back to the dealer, talk to the manager of the service department and tell him that you need a more definitive explanation before you can confidently drive this van any more.

RAY: Ask him to keep it and drive it home for a few days. Tell him to take his family out in it and see if he can get the problem to recur. If you notice a sudden deer-in-the-headlights look when you make this suggestion, you'll know you've made your point. Good luck, Gene.

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