540i shakes badly and left front wheel HOT

[wayned]

My '99 BMW 540i started shaking over 40 MPH quite badly. It is intermittmentnet however, is becoming more violent where the entire car shakes badly for a while. It settle down and returns. Also noticed my left front wheel is very hot whereas the other three are cool. Just had my brakes done but that was 6 months ago and doesn't appear to be related as the shaking on started this week. Since the shaking started I changed my wheels/tires back to summer however, this hasn't stopped the shaking. Does anyone have any ideas?

[Madtown]

Sounds like the brake caliper on that side is sticking on. The piston is not releasing & is causing constant braking. The shake could be due to the brake rotor getting so hot from sticking caliper that it is warped now.

[Aintfirsturlast]

This just happened to me a couple weeks ago. My caliper was sticking intermittently, and I had the exact vibrations, that you describe. Did you look to see if there was alot of pad transfer on the rotor on that side? Mine was blueish on the affected side, while the other was normal looking.

[wayned]

If that's it I assume the piston does release from time to time as the shaking does stop. Also it's only clearly noticable when I am over 40/50. Under 40 it's quite smooth??

the dusting is more prevelant on the affected side. Is there a temporary fix (ie. wd40?? or smacking it with a hammer??). Not sure brakes and oil a good mix but???

[Aintfirsturlast]

^^ my caliper was only sticking intermittently, causing symptoms like yours for a week or so(I figured it was a drivetrain issue, because they didn't vibrate when I applied them). If I had known the caliper was sticking, I would not have driven it.

Well, after a couple hundred miles, the caliper seized so bad that it caused violent shaking. I pulled of the highway, and the rotor was smoking and dark blue. I had to pry the caliper off with a small prybar and hammer, during replacement. You should Jack the car up, and spin the wheel. Does it spin freely, or can you hear dragging. Or does it not spin at all? That was my end result.

[shaqdeez]

It could also be a bad brake line. Brakes lines some time develop a one way flap inside because of the rubber deteriating. I have seen it a few times but rare. If you step on the brakes they work fine, but then they stay in that positions for about 10-30 seconds AFTER you let off.

[wayned]

It was a seized caliper. Replaced and all working perfectly. Thanks for your input.

[Aintfirsturlast]

Remanned, or new? I ask because I bought 2 remans, and my brakes still drag. Just the fronts. Thanks.

[wayned]

Remanned and only did the one problem. Works fine now.