Spitfire Brake Calipers

[muntsb@HiWAAY.net (Bill Munts)]

I know this has been discussed and yes I wasn't paying attention, but what is 
the best way to get the pistons out of the brake caliper?  They will come out  
a little but I think there is a ring of rust and stuff just before the seal 
that is holding the pistons in.  I remember some folks using compressed air, 
but what if one piston comes out and the other doesn't?

TIA

Bill M.
'70 MkIII Spitfire