Sounds like your brake pads or pistons are not retracting. The piston must be very clean when you replace it and the seals must be in good condition. There is a rubber grease available for this purpose. Be careful not to get any grease on the brake pads or disck. Also have a look at any other sliding parts of the brake caliper unit make sure they are clean and grease any moving/ sliding parts. Again be careful not to get any grease on the discs or brake pads.
Cheers John
Cheers John
