not too crap as you guessed, since i was working on them just yesterday i know exactly what you mean and it looks like my calipers are that type. The red grease is also what the dealer smeared on the bolts when i got replacements from them. So what is this elusive "caliper rebuild kit" that the mechanic charged me for rebuilding the calipers last time then?

halfabusa wrote: So what is this elusive "caliper rebuild kit" that the mechanic charged me for rebuilding the calipers last time then?

Mechanic speak for 'rip you off'.

these from the service bill:

caliper seal kit: 19.29
caliper seal kit: 18.35

halfabusa wrote:these from the service bill:

caliper seal kit: 19.29
caliper seal kit: 18.35

I thought these were usually replacement piston seals thingies, inner and outer.

Yes, that's all they are unless Yamaha do new caliper springs as well included in that. The tech will also have given the pistons a good clean, as they do get cruded up on the bits disc side of the seals. If they are really bad then new pistons can be purchased for about a £5 each usually (don't actually know what Yamaha charge). Amazing that the pistons cost so little and the seals costs so much.

i never touch the brake fluid reservoir....EVER.......... push the pistons back...fluid level goes back to what it was when pads/bike was new....simples..!

i do give the smallpart of the pistons revealed a go over with a toothbrush and brake cleaner before easing them back in tho... dont fix what aint broke