Thanks for the offer Al, should have mentioned I've been trying this method. All OK, no bubbles and fluid is moving through the system. The mystery to me is, how am I managing to get the pressure once the piston is pushed back into the calliper, but the pressure drops once the piston moves back to the operating position? To keep the piston back in the calliper I inserted a strip of 3mm aluminium between the piston and disc to get the piston right back into the calliper. Must be something up with the calliper/piston assembly, possibly?
