I am throwing a new set of rear pads in next week. And I want to clean up the pistons as well as possible before pushing them back in. So first,,, does anyone have a method or measurement for how far the pistons can be extended, before they pop out. I can measure the rotor thickness,, and subtract the remaining pad thickness on the old pads, to make a safe shim stack that the old pads can be pumped out against. But the pistons may be able to be advanced further than that?? Anyone know ?? The further out they are,, the easier and more thorough the cleaning. Last time I used an old toothbrush and brake fluid to clean with,, and they came out pretty good. Anyone have another tip/trick or two ?? Cheers,, Cat'