I am replacing the disc pads and rotors on my 2008 Chevy Impala.....I have noticed the rear caliper is bolted on with 2 different GM OEM bolts.....One is a regular threaded bolt and the other is a tapered threaded bolt.....I called a GM dealer, brake shops, auto supply companies and they did not know which bolt should be installed at the top or which bolt should be installed at the bottom......my question: which bolt goes where, why is one bolt tapered, is there a safety issue if you mix up the bolts?.....I have since had a UAP dealer take apart a new caliper and was told the tapered bolt was installed in the top hole of the caliper......Anyone know why the 2 different GM OEM bolts and please verify the correct position of these bolts on the caliper.... thanks

 

I did a little research on this and the bolt with the cut out at the end needs a rubber bushing installed into the detent. This is supposed to keep the brakes from rattling when not applied. The best I could find is that this bolt goes on the trailing side.

 

..Thanks for your reply....the caliper has an upper positioned mounting bolt & a lower positioned mounting bolt.....which is the trailing side, the upper opening or the lower opening?.... the comment trailing side is confusing.....if these bolts are accidentally switched in the upper or lower locations are they still holding on the caliper properly, is this safe?....many other car manufacturers also use this different 2 bolt system, yet the replacement kits sold seem to not supply a new rubber bushing....please advise....

 

If the brake caliper is mounted to the rear of the rotor, the trailing side would be the upper bolt. If it is mounted on the front of the rotor, the trailing would be the lower. I found some of the bushings in a kit on Ebay. From what I can find, I don't think it matters if it is there or not.

https://www.ebay.com/itm/Disc-Brake-...kAAOSwDYZd1ZiE