I am in the middle of replacing the rear brakes on my son's 2005 G35.

I have them both taken apart, and notice that the caliper slide bolts / pins are different. One of them has a groove near the end.

Which one goes where, top or bottom?

Also, why are they different?

Thanks,

Andy

No replies, so called the dealer. They said that the pin with the groove had a rubber o-ring. They said that there were a lot of problems caused by the o-ring, but did not elaborate on what the problems were. They recommended removing the o-ring (mine was already gone). Then, with the o-ring removed the pins are interchangeable.