40mm piston dust seal fitting tool for Honda brake callipers

thingiverse

I found a tip online about using a simple thin collar to help fitting the brake piston through the new rubber dust seal when rebuilding brake callipers, which can be a PITA with some rubber seals being very tight. I made a 3D printed one with ABS filament, as my first cardboard attempt failed to be strong enough. This size is to suit Honda S2000 13CLP15S calliper piston diameter (aprox 40.4mm). Even though it's a very very simple 'design' it saves a lot of frustration fitting the piston through the dust seal without damaging the new seal so it's shared here. So this allows you to fit the dust seal and check visually to see it's fully seated inside the calliper groove then easily slide the piston through it, and then remove the collar... Could be resized to suit any piston diameter I guess.