Topic: how much rust is too much rust?

[Blaize]

So am I being too cheap here? (yes!!!) Could these be reused or do I need to just bite the bullet and pony up another $50 for new ones. These are pictures of the worst damage to both. The one on the left is actually in pretty good shape and was working fine when removed. The right one cam in an ebay mystery caliper today and I think it may be beyond it.

[MrZxp]

The one on the left, as you say, looks eminently re-usable (definitely in better nick than any of the three on my F, and they are all working fine).
The right hand one though, does look to be beyond it's best before date... I'd recommend to put that one aside and get a better example...   

Cheers, Phil

[Jerry Rxman Griffin aka MuthaF'er]

I agree. The left one may have potential for reuse. Depends on the pitting rather than rust. Also the location of the pits. If they don't scrape by the seal it shouldn't be an issue. Some of the guys have been filling the pits. The question I would ask myself is would I rather spend the $50 now and be done with it or tear it down AGAIN soon, buy yet another seal then put that new piston in. I just recently saw a phenolic (non-metallic) piston perhaps on EBay (here maybe) for much less. On top of all that DOT3 will eat the paint on your fork leg, caliper, bracket, and rotor. Pay me now or pay me more later in this case.