Brake Caliper Issue

[bluedevil30]

I have a 2009 M35X with 175,000 miles on it.

At about 135,000 rear calipers seized. Replaced OEM rears with aftermarket calipers. At about 165,000 left rear seized replaced both (aftermarket) again and new rotors. At 175,000 left rear seized again and had left rear replaced under warranty.

Do I have a bad part issue or an issue with the brake line? How do you diagnose a bad brake line if the brakes are working fine?

[mattd860]

Did you replace the entire calipers including the caliper carriers? You could have a guide pin that's gone out. If it's not that then it's probably going to be bad rubber brake lines. When lines fail they can prevent brake fluid pressure from being relieved from the caliper when you take your foot off the brake pedal. This will cause the pads and calipers to heat up and burn out.

[bluedevil30]

The calipers were totally replaced ever time.

How do you know if the brake lines are bad and not performing right when you release the brakes? Front calipers have never needed replacing.

[Sstupid]

The caliper mounting bolts (slides) were replaced? There are rubber boots on them that expand over time due to the caliper grease and it causes the caliper to not slide. I don’t know if you’re talking about the pistons seizing or the slide part of it.