88 911 caliper piston alignment

[krshome]

I have two questions. First: can the piston angle in the calipers be adjusted without removal and how? Second:when i make a hard turn left the right wheel does a moaning/vibrating noise really loud. If I have my foot lightly on the brake it doesn't happen. I rebuilt the calipers last year and maybe put 1000 miles on since and it just started to moan now? I think i did the angles wrong on the one side. Does this sound right?

[Bill Verburg]

Originally Posted by krshome

I have two questions. First: can the piston angle in the calipers be adjusted without removal and how? Second:when i make a hard turn left the right wheel does a moaning/vibrating noise really loud. If I have my foot lightly on the brake it doesn't happen. I rebuilt the calipers last year and maybe put 1000 miles on since and it just started to moan now? I think i did the angles wrong on the one side. Does this sound right?

there are tools that rotate the pistons, Porsche tool P84 measures the angle as well


when you pull the pads the backs should have witness marks like these

[Jdub]

See here for imaginative method. You can pull the pads to be sure the pistons are correctly aligned. A rebuilt caliper with new piston bore seals may be difficult to move though.