Hey all I'm in a bit of a bind. I had a shop do some work on my car and into a three hour drive I hear a bumping on my passenger side. I finished my drive and checked it out. It would seem that the shop failed to put one of the brake caliper bolts back in. So the brake rotor is loose and moves around. I am not close to a dealership and want to see if I can replace the bolt at lowes. Does anyone know the specs for the bolt?

Ed

 

Front or rear?
These are the bolts that hold the caliper to the hub:
http://www.realoem.com/bmw/showparts...=34&fg=05&hl=1
front M12 x 1.5 x 32 (#3 on the diagram)
http://www.realoem.com/bmw/showparts...35&hg=34&fg=10
rear M10 x ? x 30 (also #3 on the diagram)

This would not cause the brake rotor to be loose, however

If you're talking about the bolt that hold the rotor to the hub, it's really not necessary as the lugbolts
do 99.9% of the work holding the rotor tight. It just hold things in place and lined up until you put the
lugbolts on.

It is number 12 on the first diagram, number 10 on the second, and the front and back ones are the same -
TORX-COUNTERSUNK HEAD SCREW M10X13
If you elect to replace it, you don't have to find a torx one, a philips or regular of the same size will work.
Use some anti-seize compound on the threads.

These often seize and shops often drill or otherwise wreck the screw getting it out and decide not to replace them.
I wouldn't be suprised if you found some of the screw still stuck in the hole. Then you need to drill it out and
re-tap the threads if you really want to replace the screw.