To cure a brake judder problem on my 06MY 4.2 SC I had my warped front discs, and pads replaced (with LR parts) by my usual local garage (who is very good but not a specialist LR Indy).

They told me the new discs had improved matters a lot but hadn't completely eliminated the judder/vibration/noise which seems to be coming from the nearside front. I'm not feeling it through the brake pedal or steering, its felt and heard through floor/bulkhead. It's similar to brake judder but not as harsh and the quality of the noise is different – hard to explain.

They found a split bush on a suspension arm (I can't remember the exact name of the part) and suggested it was this that was causing movement under braking.

New part fitted but it has not cured the problem. Garage has tested:

– run-out on discs,
– swapped discs left to right to see if problem moved,
– they have a brake tester with 4-wheel-drive mode which tests each wheel independently,
– on-road brake testing at various speeds, plus braking whilst turning left & right.

Have you checked for a seized rear caliper?

The normal signs are of juddering while braking and a very hot wheel on the side of the seized caliper.

Mike

Thanks, I'll check for a hot wheel. Just so I completely understand, by "seized caliper" do you mean the brake pistons seized in the caliper bores? 2006MY 4.2 SC
BMW R1250 GSA Rallye TE
Triumph Tiger 1050 (sold)
1979 Pontiac Trans Am (sold)

Yes, it can either be the piston corroded into the bore of the caliper (most likely) or the caliper carrier corroded and stuck (less likely).

Mike

It isn't always obvious which wheel/brake is juddering. I had a judder felt through the pedal when braking heavily. The car passed its MOT so I didn't get round to sorting it out for a while. Only when I wanted to PX the car did I decide to fix the problem.

From the general feel, I was convinced it was offside rear brake. I replaced both rear discs and pads... Still the same! So I bought a pair of discs and pads for the front. I fitted the front offside, and just for curiosity I decide to test the car before doing the nearside. Yep, still the same! I fitted the front nearside and problem solved.

So, in the end it was the opposite end and opposite side that was causing the issue. I will never assume anything with cars again. No longer FF owner but still interested. Present car Jaguar XE
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Previous car Td6 SE
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Previous LR- Disco 300TDi Auto

Just as an update for the benefit of others, the fault was eventually tracked to the rear nearside brake disc. A piece of the disc’s braking surface about the size of 50p piece had broken away, sort of delaminated to a depth of 1 to 1.5 mm.

The garage had removed and examined the rear caliper and the outer surface of the disc looked in good condition with very little scoring or wear. However, they could only see the inside surface of the disc at the point revealed by the removed caliper because the rest of the inside surface is covered by the splash shield! What they could see of the disc gave no clue as to the true nature of the problem so they concluded it wasn’t the culprit.

After eliminating everything else they could think of the boss adopted a “this is not going to beat me” attitude and did a complete strip down (of the brakes/hubs ). As soon as the disc was completely removed they saw the problem.

So now I’ve got new discs and pads all round – problem solved.

For entertainment value I think I’ll revue the dashcam footage of their road testing to listen to all the swearing.

BTW multiple short-run brake tests will guzzle fuel like you wouldn’t believe – I’d reset the mpg just a few days before taking it to the garage and it was mid-17s, when I got it back it was showing 6.7 mpg! Is this a record? 2006MY 4.2 SC
BMW R1250 GSA Rallye TE
Triumph Tiger 1050 (sold)
1979 Pontiac Trans Am (sold)

Thanks for rounding off with a solution  .
Experience is the only genuine knowledge, but as time passes, I have forgotten more than I can remember
Volvo V70 P2 2006 2.4 Petrol 170bhp Estate SE
MG Midget Mk1 1962

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Last edited by Joe90 on 13th Oct 2018 12:23pm. Edited 1 time in total

I didn’t think rear discs would warp but they did on a previous car. If you have a manual handbrake you can test the tears by pulling it on slightly while driving to see if you can feel it.

It always surprises me how such a big hunk of metal can be so sensitive to vibrations caused by things such as this
I worked on 100s of vehicles where the discs and pads are shot but you wouldn't know by driving them