I don't buy into contaminates going up the line in a sealed system. IMO Whatever is in the line belongs there. I only bleed to remove air, or any time a section of the system is opened for repair. If ya open the bleeder ya won't need the C clamp. I use to do that in the early years until I figured it a useless/messy step, for changing pads. -Staten Island Frank- In a message dated 10/6/2009 1:19:07 P.M. Eastern Daylight Time, jryan@xxxxxxxxxxxx writes: That's what I do. A bit C clamp works fine. I actually do it before >> removing the caliper from its mount. I also tend to open the bleeder > screw >> right before pushing the piston in. The thinking is to keep from >> pushing trash up the brake line. If you tighten it right after >> pushing the > piston >> all the way, you shouldn't need to bleed the brakes. >>