Mazda 3 Undiagnosable Brake Failure

Maintenance/Repairs
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1

Hello,

Recently, the brakes on my wife’s Mazda 3 (5 door, 2.3, 2005, 67k miles, automatic) failed while she was driving slowly in a parking lot. The pedal went all the way to the floor, but the car did not slow down. She used her key to turn off the engine (I’ve since suggested she use the parking brake instead). The car shuddered (presumably the engine slowing the car?) to a stop. She re-started her car and had some braking power, which returned to normal after a few pumps of the brakes.

Since then, the car has been looked at by our usual mechanic and the dealer. Neither can find anything wrong and the brakes have been performing normally.

For it’s age, the car is in good condition, has been regularly serviced, and has spent it’s entire life in southern California. The only unscheduled maintenance I can recall has been the refurbishment of the electric window switches for the driver’s door and some modest body work following a hit and run on the interstate (just dents and scratches). It’s only other issues are an occasional rough idle when stopped at a light and harsh shifting from first to second or second to third gear when the car is cold (it’s done this “forever,” and I’ve always figured one of the accumulators was a bit sticky). The car was not serviced immediately before the incident.

Is the car safe to drive? Any thoughts on what the problem might be?

Thanks for your help.

2

The 2004 and 2005 had poor brakes. My son has a 2004 and I believe there was a recall on the brakes. They were fixed properly in any case. Brakes going to the floor could mean a faulty master cylinder. Take it back to the dealer or a good brake shop this is not a job for Midas, tire shops or Walmart.

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I would not call it safe to drive. Imagine this happened as she was cooking down a freeway at 70mph and came upon a traffic tie-up. Do emphasize with her that it is a “parking” brake - it’s not all that great in an emergency - better than nothing perhaps but even then can be dangerous to use at high speed if you don’t know what you’re doing. Chances are you’re headed for a new master cylinder, but…

What was she doing in terms of driving just prior to coming into the parking lot? Was there a lot of heavy braking involved? What was the weather like? (Air temps? Moisture? Normal stuff for your area?)

Has the brake fluid ever been completely changed out?

Ask her to think back about it carefully and remember specifically - did the pedal literally bottom out on the floor of the car? Or was it just very very stiff and wouldn’t give much braking?