Warped rear discs?

knoxville · 20-08-2014, 02:51 PM

I've got a terrible rumbling from the rear discs after some Spa/Ring action. Just a light application of the pedal gives the rumble which I can feel through the car but no steering wheel shake which suggests rear issue and even when fully on it the rumble was still there...

AP discs all round and RS29s with upgraded lines and fluid.

Possible known problem with the AP rear discs? They were fairly blue on the trip but have cleaned up fine with sensible driving but still the issue remains.

Any suggestions?

Jon8710 · 20-08-2014, 03:08 PM

funny for the fronts to go,

could it be deposits on the discs ? i know mine rumble for a few days after a TD.

Rick H · 20-08-2014, 03:16 PM

Mine were awful at the end of my Oulton day, thought I'd ruined them but smooth as Pamela Anderson's chuff by the time i got home.

knoxville · 20-08-2014, 07:44 PM

Quote:

Originally Posted by Jon8710

funny for the fronts to go,

could it be deposits on the discs ? i know mine rumble for a few days after a TD.

Fronts are fine. I was hoping it was deposits, but I usually get that after not being hard on the brakes and then they'll clean up after a good pasting. Not this time. Got progressively worse as the laps went on. Might check the run out then chuck my spare pads in to see what happens.

**shimmy** · 20-08-2014, 08:40 PM

Will be deposits, never heard of rears warping. pads don't always clear it up, as deposits can collect more deposits.

Sometimes better to use different compound discs, use sandpaper or get them skimmed.

20-08-2014, 02:51 PM	#1
knoxville S3 - On the open road Join Date: Apr 2012 Posts: 81 Casino cash: $8390	Warped rear discs? I've got a terrible rumbling from the rear discs after some Spa/Ring action. Just a light application of the pedal gives the rumble which I can feel through the car but no steering wheel shake which suggests rear issue and even when fully on it the rumble was still there... AP discs all round and RS29s with upgraded lines and fluid. Possible known problem with the AP rear discs? They were fairly blue on the trip but have cleaned up fine with sensible driving but still the issue remains. Any suggestions?

20-08-2014, 03:08 PM	#2
Jon8710 S5, Sport Off, DSC M-track Join Date: May 2012 Location: london Posts: 563 Casino cash: $8371	funny for the fronts to go, could it be deposits on the discs ? i know mine rumble for a few days after a TD. __________________ 1979 E24 635csi , 730d work horse , Porsche GT4

20-08-2014, 08:40 PM	#5
shimmy CSL Register Uber-poster! Join Date: Apr 2008 Location: Uk Posts: 14,646 Casino cash: $43909	Will be deposits, never heard of rears warping. pads don't always clear it up, as deposits can collect more deposits. Sometimes better to use different compound discs, use sandpaper or get them skimmed. __________________ .

20-08-2014, 03:16 PM	#3
Rick H S5, Sport Off, DSC M-track Join Date: Oct 2012 Location: The North West Posts: 801 Casino cash: $12295	Mine were awful at the end of my Oulton day, thought I'd ruined them but smooth as Pamela Anderson's chuff by the time i got home.