Decompressing Rear Brake Calipers

Tiny
STORMT497
  • MEMBER
  • BUICK PARK AVENUE
I'm changing the brakes on a 1998 Buick Park Avenue Ultra and I'm having trouble decompressing the rear calipers. I'm not sure what the mileage has to do with my problem but I have 97K miles and the engine size is 3.8 Liter. I have already changed the front brakes. How do I decompress the rear calipers?
Thursday, July 5th, 2007 AT 3:03 PM

7 Replies

Tiny
SERVICE WRITER
  • MECHANIC
  • 9,123 POSTS
I believe those have a piston that get turned in as pressure is applied. Look for threads on the piston or a slot going through the center of the face of the piston. There is a special tool needed for that. Hopefuly it did't get damaged from forcing it.
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Thursday, July 5th, 2007 AT 3:08 PM
Tiny
STORMT497
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I noticed 2 notches on the piston but I did not see any treading. I didn't force the piston either. I got to the point where there is pressure and notice that the piston didn't move so I stopped and now I'm here looking for help. Thank You for your comment I'll look again.
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Thursday, July 5th, 2007 AT 3:23 PM
Tiny
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You need a spanner wrench to turn those calipers in, I was wrong on the description, but right on the tool.
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Thursday, July 5th, 2007 AT 4:40 PM
Tiny
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Thank You very much I'll look for the wrench. I'll let you know if that solves the problem.
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Thursday, July 5th, 2007 AT 10:07 PM
Tiny
EDBEARD
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  • 1 POST
You can rent a tool from AutoZone, or other auto parts stored just for that purpose. At AutoZone in Austin Texas, it rents for $29. You get your money back when you bring back the tool. If you don't bring it back then the $29 covers the cost of the tool.
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Friday, July 6th, 2007 AT 8:07 PM
Tiny
STORMT497
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I found a universal piston turner at Advanced AutoParts for $11 and that fixed it. The tool is a square block with 5 different settings for different sized pistons. Thanks for your help.
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Wednesday, July 11th, 2007 AT 7:22 AM
Tiny
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Cool! Another success story!
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Wednesday, July 11th, 2007 AT 10:43 AM

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