[ROVERNET - UK] P6B rear brakes

[Ray Wilkins]

Yes, back on this old chestnut again. I am in the process of replacing the
rear calipers on my P6B which is something I have not done before. When I
inserted the pads they were very tight and the disc would not move. When I
looked at the piston inside the caliper, it was proud by about 3mm. I
decided to bite the bullet and remove the calipers from the car and onto the
bench for easier access. After checking the manual and rotating the piston
clockwise it would still not move back flush with the caliper body. If I
move the handbrake bracket, the piston rotates and clicks which would seem
to indicate all is well inside the caliper (which has been reconditioned by
myself and a very experienced Rover Car Club of Australia member) but I
still cannot get the pistons flush with caliper body (it's the same on both
calipers). 
Is it OK for the piston to be proud by 3mm? or must it be flush? Apart from
rotating the piston, is there any other way of moving it back? All help
would be greatly appreciated.
Ray Wilkins
1976 P6B
Melbourne Australia