2007 Lucern CXS, 86K miles. I am replacing the rear pads and rotors for the firs time since new, I am the original owner. Using a "C" clamp (as I have done on many vehicles)and an old brake pad, I find that the caliper puck will not retract on either side. I had no problems with the replacement of the front pads and rotors when done at 55K miles. Is there a special procedure to retract the pucks on the rear calipers?
Rear break caliper retraction problem, both sides. on 2007 Buick Lucerne
by Rickford in Canton, MI on August 14, 2011
1 answer 1 comment
ANSWER by S_Rod on August 15, 2011
if the dust boot is in tact it shouldn't be rusty to cause this problem. maybe try bleeding it buy loosening the bleeder valve. although this is more work having to bleed brakes after words, this sound like the only alternative. unless you replace with new calipers. email or call for further assistance. firstname.lastname@example.org 336-712-5285 sam...
COMMENT by Visitor on August 17, 2011
Sam, Thanks a lot for responding to my question. Yep, the dust boot was intact and in perfect condition. After a couple hours of internet searching and finding out nothing new, I went back to try and figure it out. I too thought that opening a bleeder may cure the problem but it did not. Of course it let air in the line which I had to bleed out at the end. My rear calipers have a mechanical, spring return device on the back side which mechanically pushes the piston out to activate the emergency break. I disconnected the cable and manually operated the mechanism with a pair of channel locks. I could see that the piston would move out and back in about 3/16 of an inch when I did this. After doing that I tried the "C" clamp again. Much to my surprise the piston started to retract slowly into the caliper, but here's the catch... As I tightened the clamp the piston turned as it retracted, as if it was screwing back in. The other side did the same thing, but only after I manually worked the parking brake gizmo on that side too. I'm presuming that a turning motion during retraction is required to retract the piston, at least on the rear calipers anyway? The fronts did not do this at all! I'm not a pro but I do like to do minor to medium sized repairs on cars for family and friends and have done quite a few brake jobs on a variety of cars, but I have never come across a situation like this. Just glad it was on my own car and not somebody else's! Anyway, thanks again for the reply and advice!!! Rick Savin "email@example.com"