Need help quick on this one, gotta drive to work tomorrow!

I was getting started with a routine rear brake pad replacement, got the old pads off the driver side and now I can't retract the piston to put the new pads on!

I put a c-clamp on the old pad on the piston, took the lid off the reservoir, and turned but it would not retract, so I opened the bleed valve, still would not retract... i removed the whole caliper from the truck including removing the handbrake cable - and it STILL won't retract.

I put it all back together except not on the disc, with a c-clamp in place to prevent the piston coming all the way out.. had a friend push the brakes lightly with his hand - the piston came out a little bit till it hit the c-clamp. now it's stuck out even further so there's no way I could reassemble this junk.

what can I do?

edit - 1991 trooper with rear disc brakes

<small>[ June 17, 2003, 09:30 PM: Message edited by: Eric D ]</small>

note - OK i just read an archive post about them needing to be twisted, I'm going to give that a try right now... but if you have any other advice in the mean time, hook a sucka like me up! <img border="0" title="" alt="[Smile]" src="images/icons/smile.gif" />

<small>[ June 17, 2003, 09:34 PM: Message edited by: Eric D ]</small>

It gave me a headache too ... They screw back in the caliper. I used needle nose pliers to do it. can't remmeber which way to turn , but I think clockwise turns 'em in.

twisting did it... clockwise <img border="0" title="" alt="[Smile]" src="images/icons/smile.gif" />

wow thats wierd...im goign to be doign my rear brakes any day now...whenever the pads arrive from st charles, and i was wondering about what the deal with screwing the piston back in....the fella i spoke to on the phone said you coudl compress them with a c-clamp....but it appears he was out to lunch on that one.
ill have to remember clockwise with some needle nose pliers when i do mine.

it is a pita twisting those bastiches. a friend of mine made a tuning fork shaped tool on the miter to make it easier.

You should be able to pick up a universal tool at any auto parts house. They are designed to work with 3 or 4 different styles of caliper pistons. Cost about $10 and use a 3/8 drive.

the proper tool is always the best idea

to be honest though, after I knew the "trick" of twisting them back in - it was really very easy. Just keep a firm grip on the caliper and whatever tool you are using and use slow, steady force.

Mine are screwed back in with an Allen key screw hidden under a brass cap. Tooke me ages witht the first one to figure that out.

Just adding my 2 cents - I found this thread while desperately looking for help on this issue.

On my 91 Troop, the rear pistons have to be screwed in (as has been said above). There is a handy tool (the "cube"), which takes all the fun out of it.

But if you find yourself in the middle of a job, with no way to go get the cube...here's an easy way to get the job done.

I removed the caliper assembly, and lashed it firmly to the axle using some zip-ties. I was careful not to kink or strech the brake hose. Then I took a large pair of needle nose pliers, and turned the pistons about 4 turns clockwise to get them back & nearly flush with the base of the bore. It is difficult to turn with the pliers, but it will turn. Take your time.

It's important to keep the caliper assy from moving, since you'll chew up the piston top with the pliers, and rip the rubber boot otherwise. Once it's immobile, slowly go to work with the pliers.

Also take note - you only get one shot at reattaching the emergency brake cable. If you turn the actuator to attach it to the cable end (with the pin & cotter pin) - and you let go of it...the piston will do it's auto-adjust routine, as it's supposed to. Now when you go to move the actuator again for your 2nd try, it will not have enough "turn" in it to reach the cable. You'll have to remove the caliper and re-seat the piston in the bore AGAIN. Argh. So do it right the first time or spend another 10 minutes fightng with that damn screw piston! Hope this helps others...