[PG12]

recently had the driveshafts replaced - vibration when accelerating has gone but seem to have acquired a steering wheel that wobble left/right when braking - was fine before the fitting

seem to remember having this years ago but can't remember how i resolved it

re torqued the front wheels but made no difference

[BurfyBoy]

I had this recently on my brand new discs and used the eldude fix of 'braking hard' to clear the pad deposits from the discs.

If you just perform another brake bed in cycle this will get sufficient heat into the discs and clear the glaze.

[Dogsbody]

I have found this on the RPOC forum.
I'm sure Chris won't mind me putting it here as it is a brake safety issue.

Iv'e had this to a certain degree on every car iv'e owned at some stage.... and iv'e never had the disc skimmed to cure it...

Not using the brakes hard enough or just simply not using the brakes (out of season storage) causes a poor pick up of pad material onto the disc surface....

the main issue with this is to nip it in the bud before it gets worse and worse....

If it's quite bad you'll need to remove the pads and discs, srub the surfaces down, ideally with a nice abrasive garnet paper (not aluminium oxide paper)...

then go through the process of GRADUALLY warming up the disc with controlled braking on straight roads...then some long and harder braking....

If the wobble isn't too bad i generally just go straight to bedding without the cleaning...a bit of patience is needed here, you won't fix it in one session...but repeated HARD pedal pressure will scrub the discs even again and restore an EVEN LAYER OF PAD MATERIAL ON THE DISC...this is the key :idea: :mrgreen:

As you are coming down from 90-100mph (on track of course) press harder and harder without activating ABS..(dry day is good....lol)..

If you think about it from a physics point of view...with 4 piston calipers you've got the pressure from the servo divided amoungst the 8 pistons....so getting them to apply a good even pressure to the disc when you want to bed the disc in evenly isn't going to happen driving like aunt daisy...

so... yes, work them hard, but in a controlled manner when restoring the 'feel'...

:mrgreen: :mrgreen:

Regards

Chris

[dancer]

PG12, on 02 February 2010 - 11:37 PM, said:

recently had the driveshafts replaced - vibration when accelerating has gone but seem to have acquired a steering wheel that wobble left/right when braking - was fine before the fitting

seem to remember having this years ago but can't remember how i resolved it

re torqued the front wheels but made no difference

Check that no foreign matter has been introduced between both disc's and drive flange's on re-fitting.

[PG12]

BurfyBoy, on 03 February 2010 - 08:20 AM, said:

I had this recently on my brand new discs and used the eldude fix of 'braking hard' to clear the pad deposits from the discs.

If you just perform another brake bed in cycle this will get sufficient heat into the discs and clear the glaze.

had the disk/pads on for 6 months no problems before the driveshafts were changed

dancer, on 03 February 2010 - 08:51 PM, said:

Check that no foreign matter has been introduced between both disc's and drive flange's on re-fitting.

looks like a trip back to the garage

[BurfyBoy]

PG12, on 03 February 2010 - 10:00 PM, said:

had the disk/pads on for 6 months no problems before the driveshafts were changed

Mine were on 6 months and developed this over winter due to gentle braking.

Go out, give the car a thrashing with lots of heaving deceleration, if you get home & the discs are smoking and still shaking then its not pad deposits

[PG12]

did a lot of thrashing - thanks to the weather - it's more a 'pulsing' feel now rather than a wobble

perhaps the pads have stopped moving around?