Changed my front pads and had the expected T55 Torx head bolts. Went to the rear and found 15mm headed bolts, not the Torx as on the front.

Unlike the front, which took about 4-5 turns to loosen up, the rears seems to maintain a pretty constant amount of fairly high hand pressure to turn and did not seem to be backing out much, if any. I went back in with them and left them.

Wanted to see if anyone had slipped in new rear pads and what you encountered.

According to the GM Service manual, rear caliper has “caliper guide pin bolts.” Apparently, they are secured with threadlocker. As per the manual, when you take them out, you will either use new bolts, or will need to thoroughly clean the old ones, apply threadlocker (GM P# 12345493 – CAD P# 10953488) before installing back, and torque to 31 lb-ft..

Hope this helps…

Thanks, Ken. I was concerned when they still had very tough resistance with each turn. I could not see much movement backing out.

I am going to call a friend at the local GMC service department that works on trucks. I hope to take the truck and pads in and see what he does.

Thanks for the help, again.