On further investigation this weekend I have found the dust seal on one of the pistons on my passenger front caliper has a hole. This explains why the pad has been dragging and you can hear it as you drive down the road. You can force the piston in and it comes out as you brake, it just doesnt have the role on the rubber o ring to release the brake properly.

How big a job is it replace the seals?

Does anyone have a working calipper?

 

???

 

really easy to replace. get a kit from import car parts. http://www.importcarparts.co.uk/part...en=&searchKey=

you can get away with small amounts of pitting on the pistons, but if there are large amounts they will seize again.