Hi, I have a 2009 XF Supercharged with 45,000 miles on it. For some time now I have had brake problems. As the pads and rotors were worn I changed them all out but got brake judder. I decided to remove the new cheap front rotors and fit better front rotors, EBC, with EBC Redstuff pads and still get brake judder. The rotor runout is 0.001". one thousands of an inch which is excellent. So, what is causing this judder and the braking is noisy too.
I would appreciate any help on this and apologies if this topic has been posted before.
Steve

 

Sticking piston / bearing failing / suspension fault.

 

 

Thanks for the input. While the car was jacked up I checked the suspension for wear/play and as it should be at 45000 miles all joints were tight and there is no bearing noise and wheel has no noticeable bearing excessive clearance. Yesterday a friend of mine was riding with me and said he thought it could be ABS related partly due to the noise. When I changed the brakes I did push the pistons back into the calipers and now heard not advisable to do that with ABS. Any comments please? I may get the brake system flushed as it is ready although doubt that is the cause but will ask Jag dealer to check ABS.

 

Had exactly the same problem with my XFR on redstuff pads...........for me its not the rotor run out warping a cast iron disc is a myth. Its more about uneven pad deposits. I attempted to bed them in using the heat cycle bed in process and this i believe is where it all goes wrong unless you have perfect conditions. Mine were ok up to that point.......now i have judder. Going to get a new set of discs and just drive normally.......my logic.......when you buy a new car they do not tell you to bed the brakes in do they!!!?? And having worked at a few OEMs - Rover, Mini, BMW......i can tell you that there is no factory bed in process just a gentle rolling road run.

 

How else could you install the pads?

I'd go with the idea that it's pad deposits on the rotor. Very common.

 

recently had this problem on my XJ and went down many routes of new discs n pads ( which solved the problem for a short while )
All suspension bushes etc were changed out anyway, new wheels, new tyres as needed after being advised that it was not a sticking piston in the caliper.
Mine too was checked for disc ad hub run out, all seemed fine and easily within acceptable tolerances. Bear in mind if its a sticking piston acting on the inside of the disc this won't be checked for run out

The problem turned out to be a sticking piston inside the caliper
Do you have a grab / let go / grab / let go sort of sensation?
Is it ok from cold but more noticeable as the car gets up to temp?

Hope to hear

 

Had the same problem. Cause was uneven pad deposits on the disks. New disks solved it with gentle bed in. Not aggressive hard stops like i had been told were better. Not the case.

 

How else? By attaching a drain hose to the bleed nipple and opening up the nipple before you push in the piston. That way you don't force fluid back into the brake system.

 

This still invloves pushing the piston back into the caliper-which is what the OP was cautioned not to do.

If he meant don't push the FLUID back into the system, that's a different matter.

 

He clearly mentioned the ABS, so pls don't be thick about it.

 

We obviously speak different versions of English. I interpret his statement as 'do not push the pistons back if the car has ABS'.

I guess this is similar to 'I'll hold the nail and you hold the hammer. When I nod my head, you hit it.'

The idea of not pushing the fluid backwards is nothing new. I remember hearing it back in the '60s when I first started out, long before ABS became popular. I don't remember any actual cases of it causing problems though, but I do know of several cases of the master cylinder becoming over/under filled with fluid.

If fluid is being drained during pad replacement, the volume removed should be measured and an equal volume of fresh fluid be added to the reservoir after fitting the new pads. The reservoir should NOT just be filled to the max line- unless both front and rear pads have been replaced during the same shop visit.

 

Sorry to start a war of words here, so for my comment "pushing the pistons back" I meant pushing them back without opening the bleed screw. I have read pushing the piston back without opening the bleed screws can cause damage to the ABS sensors or something like that. In the sixties I also did many brake jobs and never had any problems with doing this however these days I bow to those with experience of newer technology and am appreciative of any positive feedback,
Getting back to my problem. This is the second set of new rotors and pads in 2000 miles and same problem and did not burn in pads. The pedal does feel like the ABS is operating. I have done many brake jobs in the past 50 years and have never come across this before hence my request for help.
I will take the pads out and file them flat and will clean the rotor faces then go from there I think. Keep all positive info coming please, sounds like a common problem.
Cheers

 

Can you pull the fuse to disable ABS system and see if it still does it?

 

I don't believe what you've got is common at all. Was this noise present from day 1 with new pads and rotors?

 

Mikey, I knowingly bought the car that it was very ready for a brake job so cannot tell you if it was OK previously.

BritCars, good thinking, worth a try

 

If I remember there are 2 nubs on the rear brake piston that help facilitate turning the piston in during a brake job, these nubs have to be lined up and in the slot on the pad when installed or you will get pedal shudder like crazy.

 

Which slot in the pad? I have done several rear brake jobs on this car, and there isn't a slot in the rear pads.

Do you have any pics of what you are talking about? And who told you that?

 

Having changed the pads twice on the back of my XFR there are no slots that need to be aligned.

There are two dimples in the face of the piston that I used to put a pair of needle nose pliers in and wind back the piston. Definately no slots

 

before you drive yourself crazy, have you at least thought about checking calipers for sticking pistons??
It likely may be the cause and worth at least ruling out....