Help - Sticking Brake Caliper? E46 M3
Discussion
All,
Sorry for the long post but I am after some urgent advice/help. Car is a BMW M3 E46, 53 plate on approx 85000 miles.
I appear to have a sticking caliper on the front passenger side. Under normal driving whenever I brake it does not seem to fully release and gets progressively worse. I.e. it appears to build up pressure and became almost undriveable over only about the 2 miles it took to get home (slowly!).
It is fine when starting out and when given a chance to rest it seems to recover. When I took a look the front right brake disc was extremely hot when the others are only warm (as proved by burnt finger tip - stupid I know!). So having done the usual internet searches I have conlcuded a sticking caliper.
I have several queries as the garage I use is closed until Monday.
1. Is there an obvious alternative diognosis?
2. Is there anything I can do in the short term myself (ideally I need the car for work Monday!)
3. The car has recently had two lots of work done on it - could either of these have had any impact or caused this?
The car had a new drivers side front control arm the week before christmas and seemed to drive fine then (but I only did a few miles). I cannot think of a reason the opposite caliper would be affected by this work but I am no mechanic.
Immediately after christams it had a full geo set up and quite a few adjustments made to both front and rear suspension. It was only moved about 500m after the geo set up and not driven properly until today. It seems a big coincidence that the problem would manifest straight after the geo set up but that garage (different to my normal excellent indie who did the control arm) insists they could not have caused the problem and I don't think the wheels even come off for a geo set up?!
Hopefully someone can help with a solution or offer advice. This is assuming anyone looks at the brakes and suspension section!
Thanks in advance!
Jim
Sorry for the long post but I am after some urgent advice/help. Car is a BMW M3 E46, 53 plate on approx 85000 miles.
I appear to have a sticking caliper on the front passenger side. Under normal driving whenever I brake it does not seem to fully release and gets progressively worse. I.e. it appears to build up pressure and became almost undriveable over only about the 2 miles it took to get home (slowly!).
It is fine when starting out and when given a chance to rest it seems to recover. When I took a look the front right brake disc was extremely hot when the others are only warm (as proved by burnt finger tip - stupid I know!). So having done the usual internet searches I have conlcuded a sticking caliper.
I have several queries as the garage I use is closed until Monday.
1. Is there an obvious alternative diognosis?
2. Is there anything I can do in the short term myself (ideally I need the car for work Monday!)
3. The car has recently had two lots of work done on it - could either of these have had any impact or caused this?
The car had a new drivers side front control arm the week before christmas and seemed to drive fine then (but I only did a few miles). I cannot think of a reason the opposite caliper would be affected by this work but I am no mechanic.
Immediately after christams it had a full geo set up and quite a few adjustments made to both front and rear suspension. It was only moved about 500m after the geo set up and not driven properly until today. It seems a big coincidence that the problem would manifest straight after the geo set up but that garage (different to my normal excellent indie who did the control arm) insists they could not have caused the problem and I don't think the wheels even come off for a geo set up?!
Hopefully someone can help with a solution or offer advice. This is assuming anyone looks at the brakes and suspension section!
Thanks in advance!
Jim
I'm not familiar with the M3, but...
The 'normal' problem is a sliding caliper that has a seized slider, but first impressions are that this is unlikely in your case. For one thing, I doubt the M3 has sliding clipers - surely it has opposed piston brake calipers? - and for another thing the progressive worsening and the fact that it's 'relaxing' again once you've stopped doesn't sound right.
If the M3 does have sliding caliper brakes, then take the wheel off and the pads out on both front wheels and make sure the calipers are sliding equally freely on both sides.
It sounds more like a hydraulic problem, though.
Does the diagonally opposite rear brake get hot at all (even slightly warmer than the other rear brake)? This would tend to suggest a problem with the whole of that half of the diagonally split braking circuit (ie. master cylinder or servo).
My first suspect, though, would be an internally collapsed (or severely kinked, if the car has had recent suspension work?) brake hose on the effected wheel, that's allowing you to pump fluid into the caliper, but then not letting it all flow back out. Obviously once the car is stopped, the trapped fluid would gradually seep back through, thus magically releasing the caliper.
The 'normal' problem is a sliding caliper that has a seized slider, but first impressions are that this is unlikely in your case. For one thing, I doubt the M3 has sliding clipers - surely it has opposed piston brake calipers? - and for another thing the progressive worsening and the fact that it's 'relaxing' again once you've stopped doesn't sound right.
If the M3 does have sliding caliper brakes, then take the wheel off and the pads out on both front wheels and make sure the calipers are sliding equally freely on both sides.
It sounds more like a hydraulic problem, though.
Does the diagonally opposite rear brake get hot at all (even slightly warmer than the other rear brake)? This would tend to suggest a problem with the whole of that half of the diagonally split braking circuit (ie. master cylinder or servo).
My first suspect, though, would be an internally collapsed (or severely kinked, if the car has had recent suspension work?) brake hose on the effected wheel, that's allowing you to pump fluid into the caliper, but then not letting it all flow back out. Obviously once the car is stopped, the trapped fluid would gradually seep back through, thus magically releasing the caliper.
Edited by Sam_68 on Saturday 2nd January 23:52
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