Can anyone advise me the best way to reseat a caliper piston for the rear brake system please? I have an 89 s5 and while performing a routine brake pad job, I realized that the rear drivers side had lost the bottom caliper bolt and all braking has been occurring on passenger side rear. Needless to say the caliper piston will not turn on the side that was carrying the rear braking load. I had no problem turning the piston on drivers side, but the other side won't budge. I amm doing this job as we speak so any imput would be greatly appreciated. Thanks

 

If it's seized, it will be a huge pain in the *** to unseize it. MAYBE a **** load of pblaster + a lot of rotating back and forth/attempting to loosen it up might help.

In my experiences with seized pistons, especially in the rear, I've replaced them.

Good luck

James

 

Maybe you need this tool? Pick one up at your local auto parts store.

 

If you believe the worn pads you are seeing are the results of that caliper doing all the work, chances are that particular caliper piston is frozen and holding the pads against the rotor. Before condeming the caliper, open the bleeder to see if the caliper piston can be turned in. If it can, bad brake line, but you still can't move it in, replace the caliper with a rebuilt, or used assembly. Upon assembly, make certain e brake cables are adjusted properly.
I have the entire SnapOn set and have see calipers that are frozen and can't be turned ever with these adapters.

 

Thank you very much....

 

My bet is that the rear caliper is past it's useful age. Our rear calipers suck ***** anyways. I've had nothing but problems with mine. Gunk from worn piston seals can screw it up and rebuild kits, from what I hear, aren't worth the hassle for rears because autozone sells rebuit rear calipers fairly cheap that are under lifetime warranty.