Tool for safe caliper piston removal

Lesson learned almost the hard way as piston removal can be difficult! Being warned about issues using compressed air to remove piston causes one to use caution but when 40 lbs of air doesn't work, go to 80 lbs. Positive results realized during piston flight past my eyebrows spawned research into better method needed.

I had a machinist friend fabricate this fitting from a large bolt, turning the thread down to fit the banjo bolt opening and then drilling and tapping for a grease fitting. Grease under pressure is a lot more controllable and results can be monitored during process and if piston is stuck, it is likely the bore and passages are a bit cruddy. The grease can easily be washed out during caliper cleaning possibly using a parts washer. I think that all 900 and 1000 calipers are using the same size banjo bolt so this should be common throughout the series and if not, make another to suit. It works great! See pictures showing fitting.

Compressed air works well, or too well as you found.
Wrapping the caliper in a rag as you pump air in will keep the piston from shooting across the room.

Good idea with the grease fitting.

Also if your using compressed air make sure you put a piece of wood in place of the brake pad to prevent the piston from causing any damage to the caliper.

Yep, compressed air works best--as long as you are aware of the danger and prepare for it. I also wrapped it in a rag to catch the missile...er...I mean...piston.

I was surprised the first time I tried it how quickly, and how powerfully that thing shot out of the caliper.

"For every action there is an opposit and equal reaction" :ohmy: :lol:

Right out of my ZX636 manual for the caliper re-build.... Compressed air and piece of wood.... No issues or flying bullets...

I've seen it mentioned with the grease fittings and using grease itself to pop the piston...

Not sure I like that idea of pumping grease into the caliper body... Once completed, you'd have to surely get 100% of that out of there or possible fluid contamination would be highly probable....

Ah well, most likely I'm miss understanding once again... No biggy....

I figured that if the piston is stuck enough not to want to come out easily, that extensive bore surface - cleaning would be necessary. Grease will loosen up with most brake cleaners and if inner surface is needing some resurfacing the grease is the least of your worries. A little extra cleanup is worth the ability to watch the piston ease out.On to the next issue!

One tip that was in classic motorcycle mechanics, if the piston is REALLY stuck, drill a large diameter hole in the piston, tap it and insert a bolt and jack the piston out. It destroys the piston, but the chances are it was in rough shape anyway...