Brake judder

[tanneman]

I have up to now persisted with the ongoing problem of brake judder. Feedback is through the pedal and you can feel it through the seat. I have new wheels, new brakes and pads but the judder persists.

 

At low speed up to about 60-70 mph with gentle braking the feedback is almost unnoticeable, however, at higher speeds under normal, gentle or hard braking the feedback is very noticeable.

 

No brake calipers are seized, no lip on the brake discs, pads in good condition all round. Checked it this morning when the new wheels were fitted.

 

Internet search has come up with a last resort theory of brake pad material buildup but after repeated attempt to clear this so called brake pad material it is clearly bull****.

 

I need help with this. What else is there to do. The garage don't want to do a runout check, I have no idea what the cause is and I'm swearing as I type this.

 

As a side note, it is a 63 plate VRS with the 340mm discs.

Edited 11 April, 2019 by tanneman

[MoggyTech]

1 minute ago, tanneman said:

I have up to now persisted with the ongoing problem of brake judder. Feedback is through the pedal and you can feel it through the seat. I have new wheels, new brakes and pads but the judder persists.

 

At low speed up to about 60-70 mph with gentle braking the feedback is almost unnoticeable, however, at higher speeds under normal, gentle or hard braking the feedback is very noticeable.

 

No brake calipers are seized, no lip on the brake discs, pads in good condition all round. Checked it this morning when the new wheels were fitted.

 

Internet search has come up with a last resort theory of brake pad material buildup but after repeated attempt to clear this so called brake pad material it is clearly bull****.

 

I need help with this. What else is there to do. The garage don't want to do a runout check, I have no idea what the cause is and I'm swearing as I type this.

Well the garage need to do a run-out test, as it's one of the first things checked for unexplained brake judder. Simple enough, remove wheel, fit dial gauge to strut, probe touches disc, disc rotated and measurement taken, it's not rocket science.

Other more exotic causes can be, partially clogged flexible brake line, causing ABS valves to modulate even under normal braking.

[tanneman]

It is vibration not caused by the ABS. The judder/vibration becomes less noticeable as the speed decreases during braking. That tells me it is rotating whatever is causing the issue.

[MoggyTech]

3 hours ago, tanneman said:

It is vibration not caused by the ABS. The judder/vibration becomes less noticeable as the speed decreases during braking. That tells me it is rotating whatever is causing the issue.

So more than likely disc run-out. Begs the question why won't the garage do the check?

[tanneman]

They say that if there is vibration then most likely the brake disc and not worth the effort of setting up the DTI to try and measure the run out in situ. In any case you will have a tough time keeping the front aligned while you rotate the wheel so disassembly is needed anyway for measurement.

 

However, there are 2 issues, maybe 3. This, in my experience with testing stuff, complicates matters because you need to differentiate between these issues.

 

1) Pristine Wheels/Fred the tread have balanced the wheels but I have a vibration at motorway speed and higher. This I have taken up with them but in my experience VAG wheels needs to be secured by an adapter for the wheel bolts to the balancing machine to eliminate the inaccuracy of the centre hole. They do not grasp this concept so this will be my last dealing with them. The wheels looks lovely by the way. I don't believe Pristine has got anything to do with the wheel fitment. They just refurbish/repair wheels. So Fred the Tread, which I did send a pic of the adapter to.

 

2) The obvious issue of the vibration when braking. Been with the tech for a test run to try and establish the cause. The man has more experience in these things than me. Diagnosis is rear discs or hub plus.............

 

3) The nearside wheel bearing is going. A slight humming noise and more pronounced noise when turning right. This will need fixing asap. Front or rear but the vibration gets worse after repeated braking.

 

There you have it. I can burn the ****ing thing down. I have had enough of spending money, £376 for PS4, £499.20 for wheels and fitment, £102 for alignment plus plus plus. FUUUUUUCCCCKKKKK

[gregoir]

I've not had brake judder for decades. The cure  involved disc and pad replacement.

It can be sorted. Did the judder exist before all your listed replacements? Or has it happened since?

[tanneman]

Before, I waited till the tyres needed replacement for a fresh start at sorting it. 2 wheels had a defect so I got rid of those.

[gregoir]

In my experience, brake judder was caused by warped discs or drums. Judder when not braking was usually caused by imbalanced wheels and tyres. I'd therefore concentrate on the discs and pads first.

[tanneman]

An update.

 

Had the wheels rebalanced and this noticeably improved the vibration. You must have the adapter to adjust for the PCD when the wheel is clamped in the machine using the boltholes. That ensures the wheel is true on the machine.

 

During the balancing it was noted that 2 of the refurbished wheels had defects. One was buckled and the other was running with a side to side movement. Back to Pristine tomorrow for them to have a look at it.

 

My local garage informed me the front discs need replacing. That is what caused the vibration. The reason, the rear faces were not properly cleaned when it was replaced. That and the nearside wheel bearing to be replaced. So hopefully all will be good end of the week after spending more £££.

 

I will be very pleased when all is done. Just the front bumper to be replaced after I hit a deer some time ago. That will be sorted by end of May. Yeh !!! Then the car will be ready for the outing to the International tournament in June and in August.

[tanneman]

And the garage scratched my wheels .......   

[tanneman]

All sorted, a very expensive 2 weeks but I'm happy. Apart from the cosmetic damage to my wheels which the garage will repair.

 

Just a note. Pristine had a look and the defects could be identified so that one I'll put down to the other garage having done something strange. If Pristine are good enough for Ian Poulter (the golfer) then they are certainly good enough for me. I can't fault the company as they are a pleasure to deal with.