Quote Originally Posted by airegin View Post
Hi everyone, first post here,
I just tried replacing the front brake rotors and pads on an 04 Aveo. On one side the caliper piston was so hard to compress I couldn't put the new pads in. The other was pretty hard to compress as well, I actually messed up a C-clamp.
You can't do it with a c-clamp. You need a suitable tool to compress the piston without ruining anything while depressing the piston.
Is this a sign of a bad caliper?
No, it's the same with all disc brake cars. It's always hard to depress the cylinder piston because you need to force the fluid in the sealed hydraulic system to move. Using a very large set of slip joint pliers, carefully placed against the back of the caliper and the front edge of the piston will do the job.

Should I try again with the bleeder valve open? All the threads I've read about this on the forum didn't mention the bleeder valve. Thanks in advance.
Martin
No, there is no need to open the bleed valve. But you might want to open the lid of the brake reservoir and put a rag under it - because when you finally do depress the cylinder piston the fluid will go back into the reservoir. If you added any brake fluid over the time that the pads were wearing down it compensated for the pads being worn. When you push the piston back to accommodate the new pads it will send any excess fluid back into the reservoir, and it might overflow.