Brake caliper rebuild question

craigmakes3 · 07-20-2014, 04:08 PM

I am rebuilding the brakes on my 81 sc, and am having a problem removing one of the pistons. I have spent a week trying to loosen it up with WD-40 and 150lbs of compressed air, but it just won't budge more than 1/8 inch. All the others are out, but I am at wits end with this one.

I have read the tech articles, just need a novel approach to getting this last one out. Any tricks out there for me to try?

47silver · 47silver's Garage

hydrauilic is the only way to go.
but do not use a grease gun it is a mess and will be difficult to clean
i would use the brake pedal the next time,, get some caps for the lines and use the brake to push out the disk.

kuba_kuba · kuba_kuba's Garage

Grease gun filled with brake fluid. Worked for me. Took a flier based on forum wisdom that once you take off the nozzle of the grease gun the thread matches up with the calipers. It was true! Piston out in just a few squeezes. Added benefit, safer than using compressed air.

BK911 · BK911's Garage

Hit with wd40. Then Use a c clamp and push it in a bit. Then hit with compressed air. Lather rinse repeat. It should move a little bit more each time until it pops.

47silver · 47silver's Garage

the disk can fly out at a great velocity, use the brake fluid in a grease gun that would be easy and safer.. the fitting connects directly into the caliper bleed hole.

wildturkey · wildturkey's Garage

I wrap the calipers up in a hessian bag when applying anymore than a little bit of force. Can't see what is happening, but a lot safer than being in the firing line.

SReppel · SReppel's Garage

Just did mine this past weekend on my 78 SC. Rear caliper pistons were really stuck, 100 PSI air pressure would not move them. Hooked the calipers back up to the brake lines and pump them out like that.

I used a piece of wood between the pistons that allowed for enough space for them to move but not blow out of the caliper. Used vice grips to grab them an twist them out the rest of the way.

Make sure you check you rubber brake lines if they have never been changed. Mine were pretty much collapsed inside and hardly any any fluid was coming out of the one on the driver side. Look's like the front brakes were doing all the work.

Installed stainless brake lines to replace the rubber ones. Got some really good brakes now.

Scott
78 911 SC Targa
87 944 NA Track Car