1993 lumina rear caliper

I am unable to move caliper piston back. I have tried c clamp and about everything I could think of to move this piston back. This is a new or rebuilt just purchased. The piston was all the way down but started to come out while I was connecting emergency brake cable. I did remove the bolt holding the lever for the parking brake. How do I get the piston back down. Thanks Jim Mitchell

I've heard that on some cars its kind of a ratchet thing, where when the brake is pressed, the piston moves out a notch, sort of a self adjusting mechanism. The only time I had to deal with this, when I when to push it back it, to get it in, I have to turn it, almost like screwing it in. Make sense? Try that.

There is a special tool to turn the caliper piston clockwise back intioit's bore.

The piston does ride on a threaded post. I was afraid to turn the piston, that's what I did on the original and ended up tearing the boot. I wasn't sure which direction to turn piston, seems like the original one had reverse threads. I wasn't sure if I should try to correct the problem by turning the piston or by trying to readjust the nut under the parking brake lever on the backside of the caliper. Thanks for info, still not sure which way I'll go. Thanks Jim

You're on the right track. The piston, as you say, rides on a threaded post. Generally what I do is to use a pair of needle nose pliers. Open them slightly held over the piston, put the tips in each slot on the side of the piston and turn. Sometimes its a real bear, but that's how she gets done. Umm, watch your hands on this, and use a pair of pliers that you don't care of they get slightly twisted as sometimes you gotta crank down a bit if it's been a while since you last changed pads. Generally speaking if they're THAT bad to re-compress, it is getting time to re-build the caliper.