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I rebuilt my front calipers and put new jurid pads on the front. I also had the rotors resurfaced since I had a slight vibration while braking. I had stop tech pads and would have to do the bedding in procedure a lot to keep vibrations at bay. I read here that others experienced the same issue with these pads.

After I put everything back together, I thought I was good. That is, until I tried braking at 60+ mph (fine at slower speeds). I get a terribly violent wobble in the steering wheel. If I press the brakes harder it goes away. If I keep very light pressure on the brakes the vibration stays and the car starts to get in a dangerous situation with the front end starting to thrash about.

I checked the calipers and they have the same amount of piston sticking out on both sides. I triple checked the bleeding. As soon as I open the nipple I get a nice, bubble free, stream of fluid.

I believe it's one of the rotors. If I spin the one wheel it spins and then catches/stops in the same place each time. On the other side I had to use force to push the caliper on, and it takes a little force to spin, but it doesn't catch at all.

I don't understand why if it's a warped rotor that wasn't turned properly why the car shakes, and continues to shake, when I very lightly press the brake? Why does the vibration stop when I press harder?

Thanks!
 

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I experienced the same issue and it had a different resolution each time. It was thrust arm bushings one time and a sticky caliper another time..It sounds as if you have pretty much done the caliper work..Is it possible that one of them may be sticking?..Thrust arm bushings would nave been an issue before you did the brake work I would think.
 

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Resurfaced your rotors? I thought that was a big no-no...
^^^ He hit the nail on the head lol. Start by replacing the rotors and see what happens from there. I'd be willing to bet they're the main cause
 

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Discussion Starter #6
My problem was the pad deposits left on the rotors from the stop tech pads. When I removed them I had three perfect imprints on one of the rotors. I couldn't keep doing bed in procedures. I had the rotors skimmed to remove them. I did this after reading of several others on this site doing it with good results. I also changed the pads to jurid.

I''m going to replace my thrust arms as I can move them with my hands and can move them pretty far with a crowbar. I also manipulated them a lot while checking them since I had the brakes off. I may have put one of the bushings over the line. I'll replace those and if that doesn't work I'll have the rotor thickness checked to make sure they are true.
 

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My problem was the pad deposits left on the rotors from the stop tech pads. When I removed them I had three perfect imprints on one of the rotors. I couldn't keep doing bed in procedures. I had the rotors skimmed to remove them. I did this after reading of several others on this site doing it with good results. I also changed the pads to jurid.

I''m going to replace my thrust arms as I can move them with my hands and can move them pretty far with a crowbar. I also manipulated them a lot while checking them since I had the brakes off. I may have put one of the bushings over the line. I'll replace those and if that doesn't work I'll have the rotor thickness checked to make sure they are true.
Trueing the rotor and thickness are really 2 different things. There is very little margin on BMW rotors for cutting. Sometimes you can get away with 1 light cut. A rotor slightly below BMW specified minimum thickness shouldn't be the cause of vibration. It may be slightly under thickness (meaning the piston has to come out slightly more than spec), but it is not uneven by virtue of being under the specified thickness.

Given the cost of new rotors (reasonable unless from the dealer), I would be prepared to replace after checking thrust arm bushings. If bad bushings, check procedure about tightening and when to apply load. Also look at replacing with more robust X5 bushings and note install (keyway 180 degrees different from stock M5 bushings). There is a long thread like "Crevier sucks" gives a good discussion.

Finally, double check your torqueing of the wheels. Should be done evenly in at least 2 stages and around factory spec number ( I think around 81 lb/ft), I typically use 85.

Regards,
Jerry
 

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Also look at replacing with more robust X5 bushings and note install (keyway 180 degrees different from stock M5 bushings). There is a long thread like "Crevier sucks" gives a good discussion.



Regards,
Jerry
I am only commenting because it took so long to get that thread corrected.

The keyway goes in the exact same orientation as it comes out stock. Install with the arrow 180 degrees different. On an X5 the arm is mounted in the opposite orientation with the bushing in front of the wheel.
 
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