Rear piston not moving in rear calipers...

[Mike93]

While replacing my struts and springs I had the back end of the car in the air with the calipers off the rotor and pads removed. The front end of the car was hanging out of the garage and it was getting late, had to put the car back into the garage to close the door. I towed the car back on the front wheels with the jack holding up the rear. Before towing I had to put the car into neutral. The caliper came off the rotor with ease put reinstalling was a huge PITA. It looks like the piston was fully opened? and when the pads went back onto the caliper I had to hammer the caliper onto the rotor. Not good I know. I tried many different techniques to compress the piston back in put it was not moving. Both sides had the same results.

When I shifed the tranny and had the brakes "on" but no pads on rotor, obviously the piston would have compressed onto nothing and cause it to be fully opened, right? Is there something I've overlooked with this to cause this problem? Only thing this problem resembles is a frozen caliper, but before the brakes functioned perfectly and the removal of the caliper nearly fell off. Somehow I froze the calipers but want to know if the are salvageable or if I need new ones.

Sorry for the length...Mike

 

[olympic]

The rear caliper pistons have to be turned clockwise(just like a bolt) as you push them back in. There is a special tool that you can buy for a few dollars to help you do this. DO NOT force them and don't use a channel lock pliers to turn them.

 

[RStalveyARFF]

keep an eye on your rear calipers. Pushing them back in can destroy them.

 

[jelloslug]

You broke them. Don't wait and see if there ok, there not. There is a threaded rod inside the caliper and if you forced it, it probably broken. Go get some rebuilt calipers from Autozone, I think they are around $50 each.

 

[Mike93]

I tried to force them back but they didn't budge. I put some effort into it but when I realized they weren't going anywhere I let off. After I got them on the rotor I drove a while and the pads are now pretty much wore out since they were pinched on so tight. I think the caliper must be working now because when I put on the brake I can hear the rear brakes making that lovely noise brakes make when there is no more pad left. When I let off the noise goes away.

Before dropping $100 on new calipers I'll get that tool Olympic mentioned and try that out.

 

[rangerj]

K-D tool from an auto parts store like NAPA is about $14. Lisle also makes a tool for this, sold at Sears Hardware, but it is not as good as the
K-D.

The two "****" on the tool fit in the slots in the piston.

Push in and turn in a clockwise motion until the piston is about flush with the caliper.

There is a lesson to be learned here. Any time you do a job on a make or model you have not worked on before, read a service manual for any special proceedures or specifications before hand!

We have all been there and done that!
rangerj

 

[jelloslug]

You can get the tool from Autozone as a "loner" ($35 deposit refunded when you return the tool). The Autozone tool set is excellent, I almost did not return it.

 

[Mike93]

rangerj- I hear you about researching before the job. I am usually pretty good about that, but I just assumed all caliper pistons could be compressed like "normal". My bad. And for what it's worth I was in Strongsville, OH working on the car just the other day (I saw your in Brunswick).

Is there any chance the rear pads could get any smaller? I almost lost them there so small!

 

[jelloslug]

Hey man, don't feel bad about the messing up. I messed up one of my rear calipers the first time I messed with the back brakes. That how come I know how much they cost. Keep an eye on those slider pins and the boots also. When they go it will mess up the pads in a hurry. You can get a new mounting bracket (that includes new slider pins and boots) from Autozone for $20 with no core. That really saved my butt when I bent one of the rusted, stuck in place, pins on the back brakes.

 

[SHODWN]

whoa!

What are you guys doing? The piston is out because the fluid is behind it and it just ont travel back through the bias valve..

un do the bleeders and push the piston in.. GEEZ

 

[jelloslug]

You don't have to crack the bleader valve compress the caliper, it just makes it a bit easier on some calipers. If fluid would not travel backwards your brakes would never release!