Brake Judder

[mjt]

I've recently begun to notice a judder when braking (not the sort you get from the ABS though). Last year I fitted new genuine Ford front discs and pads, this year I've replaced the rear discs and pads with third-party parts. The fronts have done about 11,000 miles and the rears about 1,000. I've just checked the runout on all the discs and they're all within spec. There's nothing obviously wrong with any of them visually. I suspect the problem is with the fronts because the steering shakes under braking. The only thing I found wrong was that the wheel nuts had been overtightened at the recent service so I've obviously refitted them at the correct torque of 85NM.

I haven't yet had a chance to road test it since but I was wondering if it's possible the discs could have been distorted by the overtightening. If not what else might be causing the judder?

[fiesta_lad]

I've recently begun to notice a judder when braking (not the sort you get from the ABS though). Last year I fitted new genuine Ford front discs and pads, this year I've replaced the rear discs and pads with third-party parts. The fronts have done about 11,000 miles and the rears about 1,000. I've just checked the runout on all the discs and they're all within spec. There's nothing obviously wrong with any of them visually. I suspect the problem is with the fronts because the steering shakes under braking. The only thing I found wrong was that the wheel nuts had been overtightened at the recent service so I've obviously refitted them at the correct torque of 85NM.

I haven't yet had a chance to road test it since but I was wondering if it's possible the discs could have been distorted by the overtightening. If not what else might be causing the judder?

Could be one of two things warped discs or u brakeing very heavy.

[mjt]

As I've already said, the runout on the discs is within spec, unless they were distorted while the wheels were on with the nuts overtightened. I checked the runout with the discs held on by a couple of the wheelnuts.

The judder is noticeable when braking gently and gets worse under moderate (NOT heavy - I don't do heavy except in emergency) braking.

[catch]

As I've already said, the runout on the discs is within spec, unless they were distorted while the wheels were on with the nuts overtightened. I checked the runout with the discs held on by a couple of the wheelnuts.

Well considering the above, would it not be better to test the brakes now you have them set up as they should be torque wise. It may mean your questions now may proved to be academic..........I keep getting the wife saying...I did I lock that door didn't I?...to which I reply, well you could give it the ultimate test...

[mjt]

I will be doing so as soon as I can. Probably not 'til tomorrow now though. Will report back after.

[alz]

I had the same problem with my Mk 2 Estate, the disks did not show any noticeable runout, but I changed them anyway, now it is fine..

[mjt]

Ok. I did about 150 miles today. I wouldn't say the problem is completely cured but it was definitely much better so, although I find it hard to see how overtightening the wheel nuts could distort the discs (after all, they're simply clamped to the flat face of the hub and the hub of the disc itself should act as a stiffener), it does seem that it has an effect.

An interesting point is that I found the nuts of one of the rear wheels were not overtightened. That one had a new tyre fitted during the service so it seems the guys in service had wrenched 'em up tight but those in the tyre depot had used the correct torque.

[catch]

An interesting point is that I found the nuts of one of the rear wheels were not overtightened. That one had a new tyre fitted during the service so it seems the guys in Service had wrenched 'em up tight but those in the tyre depot had used the correct torque.

Have you written that right ? It reads to me that the one that was not overtightened, was a new tyre fitted by the service guy's who wrenched them up tight. Which is it?

Because I think what you meant to say was, the tyre depot fitted tyre was spot on torque wise. Whereas the new tyre fitted by the service guys was tightened over the correct torque setting.

[mjt]

Sorry, that was a bit confusing The service dept. passed the car on to their tyre depot for the tyre to be fitted after the service.

[catch]

So the problem is better but still there, but less so. Not sure I like the sound of that really. I'm funny about brakes and tyres, as I rely on them to get me out of the "brown stuff" if I or another driver near me !Removed! up on the road. Did the judder appear after the new tyre was fitted, or was it there prior to that?

[mjt]

I don't remember it being noticeable before the service. They obviously had the wheels off for a visual inspection and then passed it to the tyre depot on completion. The new tyre was fitted on the nearside rear but the judder feels as though it's coming from the front since I can feel it through the steering. I'll be using the car again tomorrow so will have another opportunity to assess it. I had a good look at the brakes, both front and rear, when I did the runout check and everything looked fine. If it still doesn't feel 100% tomorrow I think I might take out the front pads for a better look, make sure the calipers are floating properly and the pads are moving freely in the carriers.

[mintalkin]

over torque on the wheel nuts will warp a disc, The disc, which gets very hot when the brakes are applied. When the disc cools and you have inconsistent tension on the lug points around the disc,so its likely to warp.check for run out again.

[mjt]

Surely they're unlikely to have warped since I checked them since I torqued the nuts up correctly?

If they have I wonder if I would have a case against the garage?

[Kyde]

Hello,

What was the outcome of this matter? I have very similar symptoms with my Focus Mk 2.5. When I bought the car it seemed that the front discs were warped ("uneven" stopping while braking). I changed the discs and it was fine for a while. Now every now and then there seems to be juddering when braking. After new pads and discs I've driven only ~5000 kms. So I was wondering that could it be that the front wheels have been over tightened and the discs are warped once again?