Most of the time it is not worth rebuilding calipers because they stick when the piston get rusty and you will have to replace the piston as well as the seal. Piston rust because the boot is torn and water penetrates into the caliper. Once the piston surface becomes pitted you can't use them. I would just go to my local auto parts store and purchase a rebuilt caliper. When you remove the brake line off the caliper, do not allow too much fluid to drain out or else you are going to have a problem with air entering into the ABS pump. Bleeding the ABS pump is not something that can be done by a shade tree diyer.

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2006 Infiniti G35
2001 BMW 3.0I E53 X5 Build date 08/2000 SOLD
Lotus Europa 1970 Destroyed by fire
Lotus Europa 1970 S2 Renault Powered
Lotus Type 52 1970 Twincam Webers Powered
PORSCHE 911 Targa 1982 The Garage Queen
Audi Avant donated to Kars for Kids
BMW 525IT Sold
Audi 4000CS Quattro Sold
Jensen Healey Lotus Powered Sold
Opel 1900 Sold
Triumph Spitfire 1971 Sold
Triumph Spitfire 1968 Sold
Plymouth "Cuda" 340 Six pack SOLD