So last night I ordered new stock pads and rotors*, and noticed HandA sells caliper rebuild kits. What are those, and is it anything I need to worry about?

* I track my car a lot, already turned the rotors once and need to do so again. And I'm freakin' tired of the dust and noise from pads like the Panther Plus and R4S. So I got all stock stuff because they're quiet and low dust, and nobody makes a good non-slotted, non-drilled rotor for the stock calipers. I'll just put on the track pads when I put on the race tires before an event.

 

The rebuild kits include the parts subject to wear inside the caliper.. the piston seal, boot, etc. and the specified lube to put it back together. Not something you rebuild all that often.. I happen to know because I stripped mine down when I plated them and put new parts in (but the old looked fine).

I agree and save my P+ or like pads for the track, but have learned to live with the R4S on the street because I like the higher friction.