The appropriate solution technique for solving groan
was determined to be a lining material modification.
A lining study was developed that pin-pointed the
major factors in the lining composition which
reduced the propensity for groan. These factors
were additional filler, abrasive, and fiber, as well as a
reduction in lubricant.
Try some CRC Disc Brake Quiet.
Also As I said here:http://www.fordforums.com/showthread...ghlight=brakes
all brakes make a noise; it's just usually at a frequency that the human ear can't hear (think about it; what would you expect placing any material against a fast spinning steel disk). That said, the ability to hear the brakes is usually caused by the pads vibrating (although brake pad dust and rough disk can also be contributors) .
Ways to fix it are:
a) Use CRC Disc Brake Quiet (pink adhesive goo) available from Repco and most autopart places. This rubbery adhesive goes on the back of the pad and in 95% of cases stop the audible squeal. I use it all the time on all 3 of my cars.
b) If this doesn't work you can cut a radial groove (same direction as if you had spokes in the wheel) in the pad with a hacksaw in the middle of the pad. Cut down to within about 1 or 2mm of the backing plate. Some good pads already have a radial groove or cut in the middle of the pad for this reason.
c) Chamfer the leading edge of the pads (the short side) so the angle of incidence with disk is around 45 degrees. Just grind or cut the corner off the leading edges (just about 5 mm usually).
d) Sand the disks lightly to remove any glaze.
These will not inhibit the performance of your brakes and are standard Porche approved remedies.
See: the sites I mentioned as well: http://www.delphi.com/pdf/sae/1999-01-0142.PDF