QuestionQUESTION: We are in the process of changing the brake pads and the rear cylinder will
not compress with a c-clamp. It doesn't budge. If one has become over
extended how do you get it to compress.
ANSWER: Because your rear caliper contains the parking brake mechanism, the caliper piston must be screwed back into the caliper. You'll need a special tool to do this. Make a trip to your local parts store or Sears and ask for a screw-type caliper piston compressor.
---------- FOLLOW-UP ----------
QUESTION: We got that special tool and tried it and it still won't budge. It will unscrew
out and go back in to that point and will not go anymore. We have also let the
bleeder valve open and tried.
AnswerSometimes, the piston boot sticks to the piston and will not allow it to turn. When this happens, I usually pry the dust boot a little out of the caliper groove and spray a little lubricant (such as WD-40) in the groove.
It's also possible that something in the caliper is broken from attempting to compress it with a c-clamp.
Do your best to try to see what's preventing the caliper from turning. If you're unable to find the problem, you may need to take your car to a professional to have it checked. Because of the expense of new calipers, I'd recommend that before purchasing new calipers on the presumption they have a problem, when there could be a much simpler issue preventing them from compressing.
