TOPIC:

The Steel Ring which the Rubber Piston Boot sits under is not meant to be removed from the caliper body.

Thats why its not shown as a separate part on diagrams.

It is "Pressed" into the caliper body at the factory and should not be removed. No need to remove it when repainting calipers, as its not seen once the calipers are rebuilt and on the bike with the Piston Boot fitted, so no problem.

There is a small void between the caliper body and the ring itself when its positioned in the caliper, for the Piston Boot to be seated in.
It is tricky to get the Piston Boot to sit under the steeel ring, but giving a smear of red grease helps it slip into place.

Pete F
UK

Just re installed the front and rear caliper and master cylinders after re build. Rear is bled and so far no leaks, front is not complete as I put the front tubes in place and as you need access to RH charging valve I had to remove the brake line at the master cylinder. I have a small compressor and just let 20 lbs build up then beeped the charging valves to 8.5 and it seems to be holding, when I put my auto tire px gauge on it the px goes to 6 or so like the manual says. I'll bleed the front soon and if it goes above -8 maybe I can fire it up.

me again, the front master cylinder which was rebuilt with a new piston asst is ok BUT it only grabs when the brake lever is almost at the handlebar, but brake seems ok, bike in lift, Ive only bled from top down, do you think bleeding from bottom up would make a difference
But the rear master cyl which was leaking before winter leaked after I put the good front mc seal on it, just the front one as its easy to change, So tonight I heated the rear piston in oil to 120C and easily removed the second seal and also the seal from the good front brake and put it on. Has anyone done this previously? If it wont hold px I';ll have to spend the big bucks fir the rear kit