Seels wrote:is it a kind of grinder wrench you are using? i made something that looks like a grinder wrench and fits into the two holes on the bottom.
Do you need alot of force to assemble it again?
The tool came from this set of tools designed for brake caliper work:
One of the disks had the proper spacing for the bottom of the group piston. The studs are a little too small, so I knocked them out, redialed the holes for 6mm (I think - you should measure the hole diameter in the piston) and pressed in a couple of cutoff 6mm bolts.
No force is needed to reassemble as long as you keep the outer spring compressed
. Cut the cable ties after the piston is reassembled and torqued tight.