Disc and Pad Wear

[Bendyminge]

Hello all, newbie here.....I bought a '22 plate B9.5 RS4 from Audi in Dec '23, the brakes sounded horrendous, so I argued with Audi to replace all pads and discs, which they finally agreed to, as it was "Approved Audi", and that happened in Oct '24. However, I've just taken it to my Audi Centre (different to the one where I bought it brake replaced) for an MOT and oil change, and they have told me that all pads and discs need to be replaced. Scoring of both front discs, and only 2 mm of pad left on 1 front and 1 x rear. The other front is a failure already, an the other back rear is about 3mm away from failure.
I do not drive this car hard, at all, I live somewhere where that is just not possible even if I wanted to, so how on earth can the discs need replacing (and pads) after only 9k miles and only 9 months in time??
Just to add, the corned where the pads have failed, had a new tyre (Cont. SportContact 6) in April, and that tyre will also fail the MOT. What the hell is going on here?? Any help would be appreciated......this can't be normal?

Thanks in advance, Ben.

[Jools]

There are disc's and pads, and there are disc' and pads.
My first set of OEM disc's and pads lasted 40k, the new ones I fitted have worn a lot better. I'm now on 101K and they still have meat on them.
Most of my driving is motorway etc, so like you; not much heavy braking.
As you haven't done much mileage if surface rust has formed on the disc's, that will then eat through your pads faster. So that could be why they have worn / scoured so quickly.
Easy way to solve it, drive your car more to keep the disc's free of rust, even if its just around the block. If its garaged, get a dehumidifier.

Regarding your tyres, Im going to suggest you get the suspension arm rubbers double checked for cracking which could be causing wheel hub misalignment and hence uneven tread depth wear followed with a four wheel alignment.

Don't forget be careful with just replacing one tyre.
Quattro system doesn't give a maiximum tread depth difference across an axle but I wouldn't let it be too big, maybe a couple of mm maximum.
Then take the average of the front axle tread depths and the rear tread depths and there should be no more than 2mm difference between axle averages.
The problem is continual speed differences in wheel speeds leads to increased heating and hence strain on the LSD's in the diff's especially if you have the torque vectoring rear axle.
I usually swap tyres in pairs by axle as needed.

I hope this helps

Regards

Joools

[Brooner]

Audi have a habbit of trying to get you to change your discs long before they need to
the wear is front disks new is 36mm worn 34mm rear new 22mm worn 20mm
so if there is still 1mm left your fine thats still half th life of the discs left they used to try it on with me but i caliper my discs every time i swap from summer to winter tryes and visa versa
all they will probably need is the discs cleaned up any decent garage will do that or if your handy you can remeove the discs and clean them up your self

[Bendyminge]

There are disc's and pads, and there are disc' and pads.
My first set of OEM disc's and pads lasted 40k, the new ones I fitted have worn a lot better. I'm now on 101K and they still have meat on them.
Most of my driving is motorway etc, so like you; not much heavy braking.
As you haven't done much mileage if surface rust has formed on the disc's, that will then eat through your pads faster. So that could be why they have worn / scoured so quickly.
Easy way to solve it, drive your car more to keep the disc's free of rust, even if its just around the block. If its garaged, get a dehumidifier.

Regarding your tyres, Im going to suggest you get the suspension arm rubbers double checked for cracking which could be causing wheel hub misalignment and hence uneven tread depth wear followed with a four wheel alignment.

Don't forget be careful with just replacing one tyre.
Quattro system doesn't give a maiximum tread depth difference across an axle but I wouldn't let it be too big, maybe a couple of mm maximum.
Then take the average of the front axle tread depths and the rear tread depths and there should be no more than 2mm difference between axle averages.
The problem is continual speed differences in wheel speeds leads to increased heating and hence strain on the LSD's in the diff's especially if you have the torque vectoring rear axle.
I usually swap tyres in pairs by axle as needed.

I hope this helps

Regards

Joools

Thanks Jools,

I drive the car daily, around 20-30 mile per day, but then the odd long jpouyrney, generally motorway mileage, so I'm still confused as to why any of ᵗʰ pads would need replacing after <10k miles. It seems very odd to me. The car is back with the Audi centre where I bought it from for review, but they are only checking the health check video Audi sent me. I hope they agree to replace them, but I do not want to put OEM pads or docs back on them, as they're clearly rubbish, or at least a bad batch that was given to me when they replaced them last year. it is out of warranty tomorrow, so not bothered about that aspect, but I do not want to be paying for these given that usual were and tear appears to be 30k miles for most people with similar driving habits.
I know this is a performance car, and therefore softer compounds etc. but less than 10k usage on a new set of pads and discs, seems completely unreasonable to me......but maybe I'm just being to hopeful of Audi's customer care.

I will let you know what Blackburn Audi say once I hear back from them.....fingers crossed.

Ben

[Bendyminge]

Audi have a habbit of trying to get you to change your discs long before they need to
the wear is front disks new is 36mm worn 34mm rear new 22mm worn 20mm
so if there is still 1mm left your fine thats still half th life of the discs left they used to try it on with me but i caliper my discs every time i swap from summer to winter tryes and visa versa
all they will probably need is the discs cleaned up any decent garage will do that or if your handy you can remeove the discs and clean them up your self

Thanks Brooner,

Like I said to Jools, I just don't agree that even the pads should be worn that much, given how I drive, let a lone the pads, but now I'm out of warrant, well tomorrow I will be, I will not be entertaining Audi for any work going forward. Let's see how they handle this job, and if they replace them, then fine, I will run those to their death, but any further work will be an Audi specialist, but not Audi. Can't be doing with these constant pushes to replace/renew things unnecessarily!

Thanks,

Ben

[Jools]

Just a thought, do you have sticky caliper pistons / slide pins? But having the problem on several calipers at once seems odd.
I had a sticky piston on a front caliper on a previous A4. The piston boot had let a little dirt in which stopped it moving back enough and heated it up. The piston had actually gone oval due to the heat which then jammed it even more. Bought a caliper rebuild kit which sorted it out.
This also murdered the pads on that side but luckily not the disc.

Just thinking out loud

Jools