When I fully seat both pads, there is simply not enough clearance between the pads to remount the caliper. I've tried 3 brands and the results are the same.

Yes, the piston is fully compressed, so the inner pad is fully seated against it. The pad material does not even extend past the mounting support, so this side is not the issue. The outer pad is also fully against its wall, top and bottom-side to side, and the pad material extends out past its mounting support like it should, except it extends well into the mounting gap, preventing the reinstall. One parts counter guy said I need to just sand the pads - sure.

I installed a new pad on the inner and the old worn pad on the outside and I had enough clearance. I can't figure out what's up and neither can my brother the mechanic. Any ideas?Thanks,

John Monday

The factory Q calipers are a single piston, floating caliper design.

One thing to check, is that you have the correct rotor. The Q rotor on the rear is NOT the vented one like on the J30, 300ZX, or the later 97-2001 Q45, but a solid rotor. You might have the rong rotors on your car.

Be usre to clean and re-grease the pins upon re-assembly.

I hope this helps.

Rotor thickness:

The rear rotor is factory spec and within tolerance noted below. Thanks for the specs. The problem would be solved if a set of new pads were each a different thickness of pamterial, but I've never seen such a set.

Even if you remounted the caliper with the inner pad missing, there just isn't enough room to slip the caliper back over the rotor. Still stumped.

Fuzzy photo attached showing outer pad fully seated. Note how far it extends into rotor gap.

the bottom pad in that picture isnt seating all the way..... Whenever working on sliding calipers, ive found its sometimes easier to take the bracket off to seat the outer pad....

It looks as if the pad bracket is slid all the way inward. Take the 2 pins loose, and remove the caliper from the pad bracket.

Vigourously clean the pins of all old grease, dust, and grime. Clean out pin holes as well. Then re-grease with Brake Caliper grease. No other grease will work.

The caliper floats on the pins and grease, to apply even pressure on the inner and outer pads. If the pins seize, then you only have 1/2 the braking force, and your pads will wear out in a short time.