Brake Judder, after 6k on new discs/pads

[Hdsn555]

In September last year, I had new discs/pads on my '67 plate L&K 140. Around approx 1k ago, I noticed the brakes starting to judder under heavy braking e.g. coming down to a roundabout from 70mph.

 

I complained to the garage last week, and they've had the car back in and replaced the front pads under warranty, as they said there was potential movement in the carriage. I've then taken the car away for a 200-mile approx round trip, and the juddering is still present, albeit not as bad.

 

I rang him to advise it's still happening, and he said they'll have the car back in again. He then called me back and told me that the discs aren't warped as he's had a tool on them to check them, but they've got 'hot' at some point (discs get hot, don't they!) he said the manufacturer won't accept a warranty claim as they're not warped. So there isn't much else they can do.

 

he's now effectively said they're not prepared to do anything unless I want to pay for new discs...

 

Has anyone had any similar experience with this, could it be something else?

[Crasher]

He probaly used a dial gauge to check for run out on the discs, this should not exceed 0.025mm. If we get a car come in with a warped disc, we do a runout check on the hub around each side of the wheel bolt and here the maximum figure is basically zero. Sometimes new discs can warp if the hub face has not been cleaned down properly, if a wire wheel won't bring them spotless, we run the engine in gear and use a flat steel block with 80 grit to grind the face clean.

 

 

[nicknorman]

It’s hard to understand how there can be brake judder if there isn’t some damage to the discs. Overheating usually causes warping ie run-out and hence judder. Obviously the runout won’t be exactly zero even on new discs, but it should be undetectable with normal test gear. So I suppose to some extent it depends on how much run-out you continue to call “no run-out”.

 

As to why the discs overheated, probably due to some slight binding due to dirt or corrosion of the calliper / pistons. Slight binding causes the discs to get fairly hot, and then when there is some heavy braking, instead of starting from cold discs you are starting with discs already quite hot, hence the overheating damage. When I replace pads I always take some time to clean up the callipers and ensure the pistons move freely, and give them a light greasing with brake grease. This takes time which costs money which is why a garage often doesn’t bother.

[Hdsn555]

Thanks for the thought so far. He told me there isn't any runout as if they put a claim into the manufacturer, they'd decline it, but if that's the case then I shouldn't be getting judder, so there has to be something wrong with the discs. But they're not prepared to do anything.

 

As the discs are still pretty new in the grand scheme of things, is it reasonable to expect this to happen after the brakes have been run in? I've owned several cars over the years, albeit not as heavy as the superb, but I wouldn't consider myself a heavy-footed braker, except for the odd-spirited drive.

[nicknorman]

6 minutes ago, Hdsn555 said:

Thanks for the thought so far. He told me there isn't any runout as if they put a claim into the manufacturer, they'd decline it, but if that's the case then I shouldn't be getting judder, so there has to be something wrong with the discs. But they're not prepared to do anything.

 

As the discs are still pretty new in the grand scheme of things, is it reasonable to expect this to happen after the brakes have been run in? I've owned several cars over the years, albeit not as heavy as the superb, but I wouldn't consider myself a heavy-footed braker, except for the odd-spirited drive.

No I don’t think it is reasonable to expect this to happen unless you did some extreme repeated heavy braking. After all, the last set of discs didn’t do it!

 

I think ultimately because life is too short, you are going to end up either living with it or forking out for new discs, but if you are up for a fight I would ask the garage to explain exactly how/why the juddering is occurring if there is nothing wrong with the discs. If that fails (and anyway, due to this garage obviously not being very good) take the car to another garage for a report on the discs and replacement. Then you can sue the first garage under the small claims system to refund for the dodgy discs.

[Crasher]

In the very rare instance of a Pagid disc from ECP throwing a wobbler, they don't even question the runout figures. That he says there is no runout but you have signs of it would make me check the rears (it does happen).

[Hdsn555]

4 hours ago, Crasher said:

In the very rare instance of a Pagid disc from ECP throwing a wobbler, they don't even question the runout figures. That he says there is no runout but you have signs of it would make me check the rears (it does happen).

the rears wouldn’t cause the steering wheel to vibrate under heavy braking though, no?

[Blue8793841]

Probably didn't clean the drive flange up properly and just slapped the discs on, unless you have a bearing on the way out.

[Gammyleg]

Maybe the ABS is kicking-in?

[Hdsn555]

Just now, Gammyleg said:

Maybe the ABS is kicking-in?

I thought that, but it’s through the steering as well as the pedal.

[Gammyleg]

It might be worth getting your mechanic to check over the steering and suspension system for signs of wear in ball joints and bushes

[Hdsn555]

14 hours ago, Gammyleg said:

It might be worth getting your mechanic to check over the steering and suspension system for signs of wear in ball joints and bushes

A good shout, not a bad idea given the car is 7 years old, and just ripped 67k.

[Crasher]

17 hours ago, Hdsn555 said:

the rears wouldn’t cause the steering wheel to vibrate under heavy braking though, no?

No