I had the first major service on my A3 (2015 2.0 TDI 184 S Line) today on 18.5k miles.  The Audi health check picked up corrosion on the outer edges of all 4 break disks and scoring across them (see pic), especially the rear disks.  Was put down as an advisory on the report.

Now I can understand pads are more susceptible to driving style and might be in need of replacement by this stage but surely disks shouldn't be corroding under 20k miles.  

Do I have a leg to stand on under warranty? Any know of any defects with A3 breaks corroding sooner than expected?  They quoted £760 for 4 discs and pads which I have passed on for now for a second opinion.  

Thanks

Hello James,

Outer edge corrosion of discs is a fact of life and occurs since water gets thrown outwards off the disc to the disc's outer edge. Once upon a time when I had hair and brake pads contained asbestos, you would find that discs lasted far longer before this characteristic became as severe as it does now, and the discs lasted far longer. Now, it is not uncommon to have to change discs at the same intervals as changing pads. What you will find is that the more the disc thickness wears away, then obviously the greater the rate of corrosion on the non- wearing outer edge. Since the dealer is not telling you that the discs are nearing their minimum thickness, then I feel there isn't anything too serious to worry about, and I would have thought that Audi would not entertain any claim on this.

Now what does concern me on a barely 2 year old car, is the amount if corrosion on the centre (hub) section of the disc and equally important the section - cross beam? - we see in the bottom left of the photo. If this was my vehicle, I would want to see this up on a ramp and inspect the surface rust situation on all underbody components and if appears to be as the sectioin in the photo shows, then I would be requesting Audi to look at this, and treat it before it gets worse. 

Hope this is of some help.

Kind regards,

Gareth.

I agree with Magnet. I wonder Jimmy if you travel much on salted roads without washing the underside of the car. Residual salt would speed up any corrosion of naked metal.

Yes, I'm regularly on salted roads first thing prior to rush hour.  I am guilty of not washing it enough this winter.

Magnet, thank you for the advise. I've found a local independent Audi specialist, will get them to put it up on the ramp for a thorough inspection next week.

Hello James,

Clifford has a good point, of course. I must put my hand up and confess that I don't wash the underside very often either (quite frequent for the paintwork)  and although our 11 year old, c140K, A3 obviously has some surface rust on non- bodywork underparts, I would say it doesn't seem as severe as your 2 year old car - judging by your limited coverage photos. 

I think it's a great idea to have an independent to look at it in detail in the first place, and I would suggest they take some good quality photos of anything they think excessive for the age. Armed with this, you can then consult with the dealer who did your service, before contacting VAG customer services.

One thing which might be worth checking on ( your independent may assist ) would be to get a build date from the VIN and compare it with the date of first registration. Has this been hanging around in a field before being registered? Others on here might be able to point you in the right direction to obtain this information. 

Just as a matter of interest, did you buy it new? 

Kind regards,

Gareth.

Gareth,

Car was nearly new, was an ex demo with 3.5k miles on it registered March 2015, I drove away with it Oct 2015. 

Have uploaded a slightly better pic from the Audi cam vid of the bottom left.

Jim

I'm looking at the component (engine mounting?) at 7 o'c in the photo. If this is typical of the remaining components underneath then this is surprising for a less than two year old car. Personally, I'd still be looking at a build date for this, so you can do some homework. Purchased at Audi main dealer? 

Kind regards,

Gareth.

I religiously wash my car twice a year whether it needs or not. <G> Seriously, I always squirt plenty of water onto the underside to get rid of salt and accumulated mud. It's a practice that kept my old Granada rust free for 20 years, and I wish I still had it now.