I have a 70 911 that has been sitting for several years. The calipers were frozen and this weekend I was able to disassemble them. When I was cleaning the pistons, I noticed one of them had pitting on the exterior surface close to where the piston meets the pad. The pitting is 1/8 to 1/4 wide and about 3/4 long. Will this affect the finctionality of the caliper? I was told that the outside lining should be completely smooth. Or, do I need a new piston? Any help would be appreciated. Thanks, Eric

No.

Clean them up with either a wire brush or a glass bead blaster. Paint them with POR-20 High Temp Grey.

Thanks, Eric.