I was wondering if someone here can help me out.

Anyways, I was trying to change the rear brakes (rotors and pads) on my 94 gsr, but I was having major problems trying to get the rotor assembly back on because the piston would not compress. So I tried using a C-clamp to compress it and it was like super hard - it barely even budged. The handbrakes were already released, so I can't figure what the heck is up with the piston. Friends tell me that the piston should just push in and out without a prob, mine obviously doesn't.

So my car is on jack stands as I speak. Any input would be greatly appreciated.