Can these be rebuilt, nobody lists a caliper seal kit? Is it just throw away?

Which then raises the question, I'm using 180mm front with 160mm Rear, if I went for Hayes Stroker Ryde Brakes, which are listed as

# Front brake 160mm or 203mm Post mount fitting, 800mm hose
# Rear brake 180mm IS, 1600mm rear hose
# Both brakes can be used with other sized rotors with the correct brackets

will the Shimano disks be OK? Can I use the Shimano mounting/adaptor blocks?

Thanks

I've never seen replacement parts for them but spares are usually pretty expensive anyway, CRC have replacement M585 calipers for £22 so it might pay just to replace.

I've just found that link :o) It says front, but the actual caliper body is the same I think and the front and rear is by the mounting block isn't it?

I think that the calipers are the same (although I couldn't swear to it) my guess would be (especially as it also mentions 160mm) that it's refering to an IS adapter.

post mount front and rear shimano callipers are the same, its just the adapter, right or left hand lever and hose length that makes the 'front' or 'rear' when you buy them with any other parts. The only exceptions are some xtr's and 5+ years old ones. So yes you'll need the new calliper and a new olive top conect your existing hose back on, and re-use the adapter from your old calliper, keeping the front 160 mount for spares.

Otherwise most disc rotors are interchangeable, with the exception of vented or floating rotors (posh hope/magura) and some of the newer flashier shimano rotors with particularly wide aluminum spiders in the middle of them.

Personally I'd go for a replacement calliper, although its near impossible to 'fix' a leaky shimano rotor or lever, when they do work they are very reliable and easy to look after. If you're happy with the performance then stay with what you know.