Time for a caliper rebuild?

[tshort]

I had a sticking front caliper on my 3.2 Carrera and reached the point where I decided to pull it off and redo the piston seals. Today I pulled it apart (didn't split it) and inspected the condition of the bores. See picture. Does this look like it's time for replating or doing a caliper exchange for some that have been completely rebuilt? I've heard that the zinc plating can flake off/wear out, and when that happens you pretty much have to either rebuild/replate them yourself, or do a caliper swap for some that have already been done professionally. Thanks for any wisdom.

[Superman]

I fall into the camp which feels the condition of that bore is not terribly important. Sure, if there is significant corrosion then it should be addressed. I would lightly sand the bore and apply Dow Corning 111 to help seal it against further corrosion.

I have seen sufficient corrosion in (non-Porsche) calipers to prevent the pistons from fully retracting...because of the buildup of rust sand at the bottom of the bore. Our calipers are not built as poorly as those of Hondas.

The sealing surface is the rubber o-ring. Not the bore.

[AG81]

While my compete rebuild of all 4 calipers (88 coupe) (Calipers Split) did not see bore wear like yours.......I agree with Superman. The sealing surface is the rubber o-ring. I cleaned, powder coated the calipers then replaced every part with new. I actually considered a brake upgrade. The truth is the 3.2 has excellent brakes. I upgraded rotors and pads and would say that I am extremely happy with the brakes on my car.

[faapgar]

I have rebuilt probably more than a 1,000 of these.Most critical area is just above the piston seal about a 1/4 inch of area.Sand that down with 180 grit to remove surface rust.Install new seal and use a light coat of Viking synthetic grease to coat it for protection.When you see the rust that transfers to the piston and makes it stick in the bore it is only from that short area above the seal.After the pistons are removed I do it over a few sheets of newspaper.Use the old brake fluid and paper and polish the the rust off the pistons.10minutes for both pistons.The only pistons that do not hold up are the alloy S CALIPERS.Pistons are crap.30 minutes prep each caliper and they are ready for pretty replate.Ciao Fred

[tshort]

Thanks, all! Really appreciate your input - thank you for sharing.

Tom