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On 7 May 99, at 22:15, Sonny8oy@aol.com wrote: > jim writes: > > > Rotate the pistons and make them right! > > i can't. it's too hard. they only need turned a little (one by about 5 deg., > the other maybe 20 deg.), but i can't find anything that will do it. last > time i tried i screwdrivered my finger. i thought i recalled keith saying a > year or so back that he had a tool designed to rotate the piston, so i asked > a vw mechanic of 35 years i know if he had had such a thing and he hadn't > heard of it. They're called piston rotating pliers, but I have never seen anything except pictures of them. I just use a metal bar and tap them around into place. But of course I'm doing this in a vice after rebuilding them, so they move rather easily. > > > this should make them more efficient though, because of the increased > > > pad-to-disc contact area, shouldn't it? :-) > > > > Sorry, no matter how I try to redefine "efficiency" I can't seem to > > make this work out in your favour. > > normal pad contact area: > __________________ > | | > |__________________| > > my super-efficient increased pad contact area: > > | > |__________________| (my ascii draðéÚ 't up to it, but imagine a line > between the 2 > open ends: this line is longer than the horizontal line in the first picture, > thus the surface area of the pad is greater :-) I understand your point and I kind of thought this was what you were thinking, but I'm afraid that you have been assuming that larger contact area will give better braking. This is not the case. The frictional drag is only a consequence of the total force on the pad and the pad area has no effect on it. For example, the later calipers, with larger pads, do not make stronger brakes. They DO give longer pad life. Your tilting pad will not give longer life, because you will have to replace it sooner--since it wears at an angle. So there should be no effect on braking force (effectiveness), and a loss of pad life (efficiency.) So I'm afraid this still doesn't work out. Fortunately there is a simple solution. Get the calipers assembled correctly and everything will settle down. Jim - ******************************* Jim Adney, jadney@vwtype3.org Madison, Wisconsin, USA ******************************* ------------------------------------------------------------------- List info at http://www.vwtype3.org/list or mailto:help@vwtype3.org