Caliper mounting bolt

[pgrindstaff]

Today I tackled replacing my rear pads and rotors. When I started mounting the left rear caliper the top mounting bolt did not torque right. The bolt is tight but the torque wrench never clicked telling me the bolt was torqued. My dad suspects that while the bolt is tight, the bolt may be bad. I have been looking around realoem trying to find the part number for the mounting bolt but cannot seem to identify it in the diagram. My best guess is that it is number 4 in this (http://www.realoem.com/bmw/showparts.do?model=HE53&mospid=47410&btnr=34_0395&hg=34&fg=10) diagram but would like to be sure.

Thanks for your help,
Patrick

[vince]

#4 is the bold that mounts the bracket the caliper mounts to. It has a normal head. #8 is the allen headed bolt that holds he caliper to the bracket. Which bolt is it that you are trying to tighten? You can find a replacement for #4 at almost any hardware store, as it's a normal metric bolt. #8 can be gotten at a BMW dealer.

If you take the bolt out, look for damaged threads or metal pieces on it and where it came from. I have seen where #8 was installed a bit crosswise and needed to be removed and correctly threaded.

Hope this helps,

vince





Today I tackled replacing my rear pads and rotors. When I started mounting the left rear caliper the top mounting bolt did not torque right. The bolt is tight but the torque wrench never clicked telling me the bolt was torqued. My dad suspects that while the bolt is tight, the bolt may be bad. I have been looking around realoem trying to find the part number for the mounting bolt but cannot seem to identify it in the diagram. My best guess is that it is number 4 in this (http://www.realoem.com/bmw/showparts.do?model=HE53&mospid=47410&btnr=34_0395&hg=34&fg=10) diagram but would like to be sure.

Thanks for your help,
Patrick

[pgrindstaff]

The bolt I am referring to is one of the two bolts that secures the caliper the strut. I suppose if it is just a 15mm bolt I can run by home depot and try to find one that is about the same.

[e34.535i.sport]

What you describe is a little confusing... It sounds like you are describing the allen bolts (#8) that attach the caliper itself to the carrier, but can you use a torque wriench with allen bolts (I don't know)? The carrier bolts that connect to the car itself are hex bolts so I would imagine you mean these... I have had trouble getting these aligned before but if its not tightening up correctly or getting too tight I always back it out and try again.

[Ross]

The bolts holding the caliper bracket usually have thread locking compound on them. Remove the bolt and clean it with a wire wheel, try again.
Regardless of why it is or isn't tightening smoothly if the wrench didn't click you haven't reached the prescribed torque.

[pgrindstaff]

Alright, pulling the bolt out seems to be the place to start at this point. I apollogize for my poor description, I am having trouble finding the correct words to use. Here is a picture compliments of bmw-540i.com showing the bolt I am referring to:
http://www.bmw-540i.com/1995-540i-brake-pad-rotor-replacement/images/caliper-mounting-bolt-bottom.jpg
Though he states the bolt is 19mm, it is 15mm on my car, typo maybe? For more description look here (http://www.bmw-540i.com/1995-540i-brake-pad-rotor-replacement/index.php) and scroll down to just after he is unplugging the brake wear sensor. I appreciate everyone's help and again apollogize for my poor description.

[e34.535i.sport]

Alright, pulling the bolt out seems to be the place to start at this point. I apollogize for my poor description, I am having trouble finding the correct words to use. Here is a picture compliments of bmw-540i.com showing the bolt I am referring to:
http://www.bmw-540i.com/1995-540i-brake-pad-rotor-replacement/images/caliper-mounting-bolt-bottom.jpg
Though he states the bolt is 19mm, it is 15mm on my car, typo maybe? For more description look here (http://www.bmw-540i.com/1995-540i-brake-pad-rotor-replacement/index.php) and scroll down to just after he is unplugging the brake wear sensor. I appreciate everyone's help and again apollogize for my poor description.

Hey again, yes that is one of the carrier bolts, should be a 15mm bolt. Hopefully if you back it out clean it and try again it'll go in properly.

If not the part numbers for top and bottom bolts: 34211164125, 34216772884 - order new ones and hopefully problem solved?!

[mattyb]

rare thing to happen, maybe wrench stuffed?

[pgrindstaff]

I suppose the wrench could have fouled up or it slipped to a higher torque but it worked fine when I put the wheel back on. Must have just gotten the bolt in awkward.