Brakes "stuck" and burning up


#1

Hello CarTalk. I am not a car person but I need help. I am taking my car in to a shop tomorrow, but if I could get a little forewarning I would be very happy.

Basically, my car (2002 Mazda Protege) has been acting like my brakes are engaged. Not all the time, though - The first time I get out and drive it, it drives smooth as silk like always. But then after I put it in park and then get back in and head out (I’m a delivery driver, so this is constant), sometimes it feels like the brakes are constantly being pressed. No, the emergency brake is not on. Most of the time it’s almost not even noticeable so, like an idiot, I put it off for the past week. But today, it was very, very, very bad. I was having to press the gas to the floor to get up to speed, and then it was constantly trying to slow down. My brakes were definitely getting burned up while it was doing this, but luckily it stopped.

It may be unrelated - I know I have an oil leak, but today I saw a very unusual spot where something leaked out in my driveway. I checked my oil, and it was where I expected it to be, but this was a relatively large stain which would be very unlike my current leak.


#2

Something in the brake system isn’t working correctly.

You’re wise to bring it in and have the brake system checked out.

Tester


#3

My wild guess is that you may have a sticky caliper or two. But there are so many other possibilities such as collapsed flex lines, a master cylinder sticking, and even brake pedal linkage to the power rod that goes into the master cylinder to push the piston, that I’m reluctant to pre-guess the shop that’ll be doing the actual diagnosis.

The only thing I can tell you is that it’s good that it’s getting looked at. This problem could manifest itself as secondary heat-related failures such as a tire blowout, overheated brake fluid, and even heat-damaged wheel bearings. Or, even worse, sudden catastrophic failure of a brake line/component seal due to heat… and sudden total brake failure. You may even want to consider having it towed to the shop rather than driving it.

Whatever the shop diagnoses, I strongly recommend a system flush with fresh fluid after the repair… that is, if he neglects to mention it. This should be done periodically anyway. I do mine every 4-5 years.


#4

Rub your fingers on that new stain. What color is it? What does it smell like? You could sop it up with a white paper towel to help see what color.

The caliper sliders can freeze up if not greased properly. I learned that the hard way once.


#5

Fender1325: Nondescript brown, I assume oil. It’s just rather unusual. It normally leaks quite slowly, so that’s annoying.

Moutainbike: Thanks for the info. I’m just crossing my fingers that I don’t need a master cylinder replaced. I can afford these repairs, I would just prefer… not to have to.


#6

I’m going to say that you may have a bad rubber brake hose on one of your brake cylinders. Just check each wheel for a “hot” brake when you end a long drive. That will usually give you some idea of the problem area. I just replaced a rubber brake hose last week on my Dakota. It was easy to pinpoint because the brakes on that wheel let out a little puff of smoke when I stopped at a red light. No problems since.


#7

@missleman nailed it… I’d have to say that 90% of the time it is a bad brake hose that causes this issue. What happens is the brake hose is collapsed on the inside to the point where it will allow brake fluid to go through under pressure when you step on the brake pedal. The collapsed area of the hose then won’t allow the tiny amount of fluid that was pushed through to escape. THAT"S what keeps your brakes applied. As missleman said, you will probably be able to feel the excessive heat given off at the errant wheel. I measured one with an infrared laser thermometer a couple of weeks ago. Three wheels were in the 150º to 180ºF range, The fourth was over 450º. It won’t take that long for the heat to build up. Maybe a mile or so, if you use the brakes.

Please tell us you will be taking it to an independent shop, NOT a chain store where you will almost undoubtedly need a complete brake job. You may anyway, but click on the Mechanics Files link at the top of this page to find a good shop near you.