2004 Mazda MPV brakes freeze intermittently while driving I

MBENOWITZ

MEMBER
2004 MAZDA MPV

Brakes problem
2004 Mazda MPV 6 cyl Automatic 58000 miles

This problem happened a few times last winter and is starting to happen again now that cold and snow have set in. While driving on the freeway (after not needing to brake for several minutes or more), when I apply the brakes the brake pedal is hard and doesn't go down at all, and the brakes don't work. It did this a couple times after being parked all day, too. It feels as though the brake pads or rotor have frozen and won't stop the car. I have pumped the brakes a lot and after 5 to 15 seconds the pedal & brakes work fine again. It is scary and dangerous to not be able to brake at times, though. It seems to only happen when it gets very cold (below 10 F, I'm guessing). The brakes do not make the vibration and noise that happens when the anti-lock mechanism goes on, at these times. They simply do not stop the car. I don't know if the problem is the brake pedal or the brakes themselves. It can happen when the car is fully warmed up and has been driving for awhile, as well as after being parked for hours in the cold. I took it to my regular mechanic last winter and they said they didn't see anything wrong. Now that it's happening again this winter I'm not sure who to take it to.

1 Reply

JACOBANDNICKOLAS

MECHANIC
109,709 POSTS

Based on your description, I feel either you have a bad power brake booster or the vacuum line from the engine to the booster has a leak and the cold weather is affecting it.

THe booster is mounted to the firewall behind the master cylender. It is a large round vaccum tank that assist you when you press on the brakes. It receives vacuum from the engine that makes it work. If the vacuum is leaking out, the brake pedal will get very hard to push. You will have brakes (to an extent) but they become extreamly hard to work.

Here is what you need to do. Go to a local parts store and see if they will lend or rent a vacuum gauge. Disconnect the vacuum hose between the booster and the engine (aprox. 5/8" OD hose) Next, connect the vacuum pump / gauge to the booster and using the tool, create a vacuum within the booster. See if the booster maintains a steady pressure or the pressure drops. Make sure that the vacuum hose you use is good with no leaks. IF the pressure drops, replace the booster. IF it holds pressure, check the vacuum hose from the engine to make sure it is not cracked, dryrotted, damaged. If you find a problem with that, replace it. The hose will cost around 2.00 but the booster could be around 100.00 if it is needed.

Let me know what you find or if you have other questions, and thanks for using 2carpros. Com.

Joe