I'm in the process of rebuilding my front brakes, and I noticed the pistons have some rust on them, and a couple of scratches/grooves on the contact area. Should I sand the piston down and clean up as much of the rust as I can, or just buy new pistons? Does the cylinder bore need to be perfectly groove free because I noticed a couple of areas where there are light scratches...hopefully I dont need an entire new caliper assembly.

TIA,

Sri

 

I've never replaced mine on the race car

 

I didn't change mine either. One had much of what you describe but it polished up fine. Do you have a polishing wheel? Some rubbing compound would probably take it off.

 

Yeah, if the circumference of the piston itself is scored you might want to try lightly polishing the surface. I wouldn't worry too much about the contact area that touches the pads unless it's seriously dented, as that will cause uneven pad application. If the bore itself is scored as well then I'd start thinking about new calipers. The least thing you need is a piston to cock in the bore and prevent the pad from retracting properly. Bad juju.

 

 

 

I meant rabbit in the cock of course