I recently bought a 94 GSR and the time came for a new set of rear pads.

When I took the RR caliper off, I was shocked to see a completely torn and tattered piston boot (rubber sealything). After removing what was left of the boot I examined the piston and I'm not too optimistic about what I saw...

The very end of the piston (near the + end) is nice and shiny, but back further (towards the caliper) there is a ****-ton of corrosion on the piston. It looks like the boot had been torn for quite awhile.

I haven't done anything with it yet. Obviously I need a new boot. I am scared to screw the rusty section of caliper back into the caliper body though. Would this damage the walls and destroy the caliper body? Can I "clean up" the piston? Is it already beyond rescue?

TIA for any insight or advice....

 

Bump before bed...

Nobody's seen this happen before?

 

I don't know if this helps you any but you can get completely rebuilt calipers from places like napa or autozone for like 50-70 bucks with the core charge. I had to change out one of my front calipers and it was about 70 bucks so I'm guessing the rears should be alot cheaper.

 

option 1:get a caliper rebuild kit and a brake cylinder hone from an autoparts store or the dealer. rehone the cylinder to remove the corrosion and rust, order a new piston if you have to from the dealer. assemble the caliper and bleed the line.

option 2: get a new caliper from the dealer ($) or get a remanned caliper from an autoparts store for cheap. install either and bleed the line.

I would go with option 2, its supprisingly cheap to get a remanned caliper and its alot less labor intensive than rebuilding your own.