Hi Martin, When you say you "Lift the caliper up" Im presuming its still connected to the car via hydraulic hoses etc.You'll find the piston does not "screw in", but pushes back into the body of the caliper.You need to make sure the cap is off the brake fluid resevoir and then EASE the pistons back in.Something like a large set of mole grips or dogs makes it easier to squeeze them back,but be careful not to damage the seals.Once the new pads are back in,you need to replace the cap on the resevoir and pump the brakes to take up any free movement..
Ma6ician, October 2008
