Brake Tool

[Steinbru@VNET.IBM.COM]

Don't know if it applies to your particular brake piston, but I have a
medium sized adjustable wrench which I've drilled to accept steel pins
(I cut off the shanks from some broken drill bits from my junk box).

Drill one hole in the side of each jaw and you have an adustable pin
spanner.  Drill two holes if you need different size pins.  It's a good
general purpose tool, and was inexpensive.

Would this work in your case?

--Gary