Front Brakes

Today I replaced the rotors and pads on my 95 XJ. I used Wearever parts from Advance Auto Parts. My first question is: Should compressing the caliper piston back into the bore require a lot of force? I had to put a piece of scrap wood on the inside of on of the pistons and push it in with a very large c-clamp (other side on the back of the caliper). I didn't notice any leaking around the caliper, and the fluid did return back to the reservoir as it should. But this caliper was much harder to push in than the other one. The second question is: When I bear down on the brakes (not to a screaching halt, but with a moderate amount of pressure), should I hear a little rumbling from the pads? The XJ doesn't pull to either side, and it seems to brake just fine. I just hear a tiny amount of scraping noise when I brake hard and I can also feel the vibs in the brake pedal. Maybe this is just the new pads getting broken in? Thanks for all of your help!
Matt

Matt, I had to put my calipers in vise to compress the pistons when I did my brakes.

--Matt

I think you're ok, Matt. A small amout of "scraping" noise is normal until they get broken in.

I am going to have to take mine apart again. When I did the fronts last winter, I left off the pad shims (the ones with the sticky backing). BTW, what do these shims do, prevent squeeling?

Thank you guys. That makes me feel not so nervous about the brakes now. As far as I know, the shims are for squealing. The directions on the high temp lube I bought said to put some on the back of the shims. Thanks again.
Matt