2001 S60 2.4T AWD Vibrating steering wheel when breaking

[S60MUM]

Hello,

Truly driving me crazy, I know what you are thinking -warped discs- ... But....

I changed the original Discs and pads which were worn to new Brembo's and Brembo pads. All ok for the initial 500km. Then, I drove to Holland (1000Km) and while driving there I noticed the steering wheel started the vibrate under braking, increasingly so, first only at high speeds then also lower...vibrating, at times very badly.

Very weird but ok, 3 garages all pointed to the disks, had the discs resurfaced and changed plus a slightly worn balljoint and tie rod end and some suspension rubbers. Yay! All was well again...for about 500km, then the vibrating when breaking started again...getting worse and worse, again.

To check, as all problems started when I changed disks, I changed back to the original discs and guess what? Vibrating stopped, yay right? All is well again....for a couple of 100kms...then guess what ?!?!?! it started again.

Testing to see if wheel bearings were worn, could not detect side play/movement between 9/3 6/12, so no obvious issue here.

Also, cleaned ABS sensors even though no warning light was present, one side had a light dust blanket and vibrating slightly improved but certainly not good. Could it be that the disc has been damaged due to this ABS overworking on that side?

Drove more then 3,000 km with this issue now, and also been to 4 garages who can say nothing but "change the disc and pads"

Really want to narrow down the issue before spending on a new set of Discs and Pads again.

Does anybody have any clue what could cause this? Any input is very appreciated

2001 S60 2.4T AWD 110K Km

[gjr0]

Use a dial indicator to check the runout on the disks. It should be less than 0.04mm ( 0.002"). A bit small to judge with a wire pointer, but maybe...

You might have a sticky caliper that is overheating the disk.

Greg

[S60MUM]

Thanks Greg,

Brakes calipers were checked and are ok. As for runout on the disks, they were changed 3 times, resurfaced...something else seems to be going on.

Cristina

[gjr0]

Hi Cristina,
Something else may be going on, but if the disks are out of spec. they will make the steering wheel shudder when you step on the brakes. If the rotors are warped, all you can do is replace them. Resurfacing them usually does not solve the problem. In normal use, the disks should heat up evenly and expand at a uniform rate. Warping without overheating may point to a quality issue (hard spots) or poor technique (dirty hubs, uneven torque) when reinstalling the front wheels.

You could have just been unlucky with the rotors you got, or it is time to look for something else: bad caliper, internally swollen/deteriorated rubber brake line, etc. Are both rotors warped ? Does the car stop straight ?

Do you have access to an infrared (noncontact) temperature sensor ? After driving the car in stop and go conditions check to see if both front hubs or calipers are the same temperature. You might be able to tell by just touching the wheel. Is the wear on the brake pads symmetrical from side to side (outer right vs outer left, etc.) ?

Greg