ChatterBank2 mins ago
overheating brakes
I replaced all the discs and pads on my BMW 525i ( 1989 G reg) to get through its MOT last October.
Since then, it has done ~7000 miles. No problems.
A few days ago, I noticed vibration whilst braking, from the front wheels. The offside pads seemed to be binding. I stripped down the brakes, found nothing obviously amiss.
Yesterday, I noticed after a short journey ( 2 miles) that the offside wheel was very warm and there was an odour of something very hot. The nearside wheel was cool to touch.
Could the disc be warped, or does it sound more serious ?
Help, anyone.
Since then, it has done ~7000 miles. No problems.
A few days ago, I noticed vibration whilst braking, from the front wheels. The offside pads seemed to be binding. I stripped down the brakes, found nothing obviously amiss.
Yesterday, I noticed after a short journey ( 2 miles) that the offside wheel was very warm and there was an odour of something very hot. The nearside wheel was cool to touch.
Could the disc be warped, or does it sound more serious ?
Help, anyone.
Answers
Best Answer
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For more on marking an answer as the "Best Answer", please visit our FAQ.It's very unlikely to be a disc fault: aftermarket ones usually come out of the same factory as o/e, and it's easy to check for runout; just spin the wheel and eyeball the disc. It'll be obvious if its warped enough to cause overheated brakes.
You have a sticking caliper: it's rarely a problem with the caliper which causes this, it's a symptom of a faulty brake hose. This is pretty common- the hose breaks down internally, and acts as a one way valve for the brake fluid; consequently, as you release the brake the fluid can't get back up the pipe and the brake stays on.
It's easy to check, remove the flexible hose and blow through it both ways; the resistance should be the same but with a faulty one you find its harder to blow one way than the other.It's a simple test, and can save the cost of a new caliper. Check it first.
You have a sticking caliper: it's rarely a problem with the caliper which causes this, it's a symptom of a faulty brake hose. This is pretty common- the hose breaks down internally, and acts as a one way valve for the brake fluid; consequently, as you release the brake the fluid can't get back up the pipe and the brake stays on.
It's easy to check, remove the flexible hose and blow through it both ways; the resistance should be the same but with a faulty one you find its harder to blow one way than the other.It's a simple test, and can save the cost of a new caliper. Check it first.