Surface of brake discs rust quickly

[simonharper]

Hi, noticed that recently my discs are rusting on the surface much more quickly these days - causes them to make a horrible scraping noise for a few miles. Is this just due to the wet weather or does it mean my discs are needing replacing soon?

[Warrior193]

Hi Simon, probably just the weather 😒 especially if the vehicle has relatively light usage. 

[Ootohere]

Cosmetic rust, pads might need replacing, technician or service desk staff might tell you 80% worn when not even 20% worn.   You might say how old the car is and how many miles, and what you consider as soon.   Servicing brakes annually is an idea, and maybe post pics of the condition if told at a dealership the discs need replaced. 

[BoxerBoy]

It's very common.

 

Though I'd say my discs look worse than any other car in the street.

 

Skoda do fit rubbish.

 

My first Kodiaq got 2 full sets of rear discs under warranty.

 

This one has had one replacement set at the first service 11,300 miles - no argument - and I'll be asking the dealer to "take a look" at the second service in February.

 

Mine look terrible right now because the car has been sitting 4 days in bad weather.

 

I'll give the brakes a good workout soon to shine them up a bit.

[SurreyJohn]

Very common this time of year, roads are often wet.

 

Will rust much faster when splashed by damp from a salted road, as the salt water is lot more corrosive than pure rainwater.

 

There is not much you can do to change it apart from move to a hot dry country.

 

If a dealer tries the high percentage worn trick, ask for the millimetre readings.  I once had a dealer say my brake pads were 75% worn (never used them since), another dealer following year said pads just over half worn, so pads apparently grew back about 20% in a year.  

 

 

Edited 13 January, 2023 by SurreyJohn

[simonharper]

Thanks or all the replies folks. I guess it's just the crappy weather. Discs (the area not touched by pads) are really rusty and make the Sportline wheels look rubbish. Callipers are also very rusty - more than I'd expect on a MY20 car!! Pads are 50% worn front, 40% rear. Just has an oil service and this is what the dealer stated. No measurements for the discs at all. Mileage is 22,890 - so not that much for a MY20.

[SurreyJohn]

19 hours ago, simonharper said:

Thanks or all the replies folks. I guess it's just the crappy weather. Discs (the area not touched by pads) are really rusty and make the Sportline wheels look rubbish. Callipers are also very rusty - more than I'd expect on a MY20 car!! Pads are 50% worn front, 40% rear. Just has an oil service and this is what the dealer stated. No measurements for the discs at all. Mileage is 22,890 - so not that much for a MY20.

Rounding pads thickness to nearest 10% suggests it was more a cursory glance than an actual measurement.

 

Therefore should be able to double the mileage before pads are worn out, however probably best to get them checked again 15k miles to cover change of driving style or inaccurate measuring.

 

[Avocet]

How rusty is rusty?  A quick tour of our drive this morning, revealed the following:



A 2 month old BMW which was driven yesterday afternoon:




a 12 year old Mazda 2  (Brake discs are cheap aftermarket about 3 years old), last driven on Sunday morning:




a 5 year old Kodiaq rear (Mintex "uncoated" disc fitted about 9 months ago, last driven on Saturday afternoon:




5 year old Kodiaq front disc, Mintex "coated", also fitted about 9 months ago, last driven on Saturday afternoon.

 

Edited 16 January, 2023 by Avocet

[simonharper]

Getting towards the 5 year old Kodiaq rear (Mintex "uncoated" disc level by morning. Disc hubs are not as rusty. 2 year old car so perhaps standard fit is not coated?

[Avocet]

I think standard fit is probably "recycled old manhole covers"!

 

[kodiaqsportline]

This has been a VW group issue for as long as I remember. If you ever get a chance to see brand new cars that have just been delivered to the dealership ( before the centre disc caps are fixed ) you'll be shocked at how much surface rust has gathered.

 

Check out this review of a  +£100k Audi.   Audi RS6 long-term review  Even their ceramics act like rust magnets!

 

Of course all manufacturers suffer from this problem, but if my experience is anything to go by, VW group wins the race for the fastest build up of surface rust.

 

 

[simonharper]

Well I'll for sure be looking for coated ones when they need changing - which will be soon I think. Callipers also look like they been at the bottom of the sea for 200 years!

[BoxerBoy]

On 16/01/2023 at 23:09, Avocet said:

How rusty is rusty?  A quick tour of our drive this morning, revealed the following:



A 2 month old BMW which was driven yesterday afternoon:




a 12 year old Mazda 2  (Brake discs are cheap aftermarket about 3 years old), last driven on Sunday morning:




a 5 year old Kodiaq rear (Mintex "uncoated" disc fitted about 9 months ago, last driven on Saturday afternoon:




5 year old Kodiaq front disc, Mintex "coated", also fitted about 9 months ago, last driven on Saturday afternoon.

 

 

That's almost nothing compared to some of us.

 

Go give them a good exercise and they'll be shiny all round when you get home.

[simonharper]

3 hours ago, BoxerBoy said:

 

That's almost nothing compared to some of us.

 

Go give them a good exercise and they'll be shiny all round when you get home.

And next morning rusty and noisy again

[Avocet]

On 20/01/2023 at 20:38, BoxerBoy said:

 

That's almost nothing compared to some of us.

 

Go give them a good exercise and they'll be shiny all round when you get home.

Certainly, none of them are anything that I worry about.  First few hundred yards and they'll be cleaned up again on the friction surfaces.  To be fair to modern car manufacturers, I think discs and calipers have always done this, but with modern wheel designs, the wheels are so big, and the spoke pattern so open, that you get to see a lot more of the disc and caliper than you would have done on a car 20 or 30 years ago.

[linni]

Rust is a piece of cake. Had all discs changed 3 months ago. Choosed Brembo as a reliable brand. Lasted only 15 000 km. Fronts wobbling like hell, went back to factory ones.

[kodiaqsportline]

Just as a follow up to this. I dropped my car off this morning to have a quick pre- MOT check at a popular indi service centre. On my way back to collect the car, my head was down trying to avoid the wind and rain and noticed all the new cars sitting at the Ford dealer forecourt had said rust on their discs. Then I passed the MG dealership - all their new cars had surface rust on the discs too. Mazda? Tsame story. And finally the Kia dealer, all their new cars outside on the forecourt had surface rust. As long as the car is being used, surface rust isn't an issue.

 

Back to collect my car. It's covered just over 13k miles in 3yr and same report as it's last service a Skoda dealer - corrosion on rear discs outer edge. Unlikely to be an MOT failure but rather an advisory. Said I could ask Skoda as car still under warranty but they're likely to refuse given the mileage. I won't bother asking. Confirmed it's a common issue on the rears with VW group cars.

 

I never asked him for a quote to replace the discs but cheapest parts I can find are approx £116 for Bosch / Brembo ventilated discs, and approx £36 for Bosch / Brembo pads. Labour to fit would be around £70 at an indi in this area.  So around £210 to have them replaced. Even if Skoda said they could replace them for £100 I'd still take the Bosch or Brembo option. Why would I ever want to have the same OEM discs / pads again?

 

Not sure who the OEM manufacturer of VW discs are, but I'm guessing Catherdral City for Skoda and Davidstow for Audi.

 

In all seriousness, their discs are likely to be sourced from the same manufacturer who produces their wiper blades, becasue they're sh1te too.

Edited 19 October, 2023 by kodiaqsportline

[silver1011]

If the calipers are rusty too then this is usually a sign of aggressive acidic wheel cleaners.

[kodiaqsportline]

7 minutes ago, silver1011 said:

If the calipers are rusty too then this is usually a sign of aggressive acidic wheel cleaners.

 

Not anywhere near my car !  I use zipwax, a sponge and plenty elbow grease   The car is normally taken on a run for a few miles after cleaning just to dry things off.

 

The calipers are fine.

 

Now if you were to say I'm guilty of overwashing the car, my neighbours would agree with you.

Edited 19 October, 2023 by kodiaqsportline

[silver1011]

It was the OP that mentioned rusty calipers. The disc surface and hub are well documented for corrosion, but if the calipers are also rusty then this is normally a sign of overly aggressive wheel cleaners.

[BRUN]

if it bothers you, you can use Bilt Hamber Atom Mac on them

 

but it is normal

[simonharper]

On 19/10/2023 at 21:08, silver1011 said:

It was the OP that mentioned rusty calipers. The disc surface and hub are well documented for corrosion, but if the calipers are also rusty then this is normally a sign of overly aggressive wheel cleaners.

Thanks @silver1011, I think this is the case. The previous owner must have used something on them or took it to a dodgy car wash place. Discs now replaced and they don't rust up nearly as much as the old set.

On 20/10/2023 at 10:09, BRUN said:

if it bothers you, you can use Bilt Hamber Atom Mac on them

 

but it is normal

Thanks @BRUN, discs now replaced and they don't rust up nearly as much as the old set.

[CainDingle]

On 18/01/2023 at 23:01, kodiaqsportline said:

This has been a VW group issue for as long as I remember. If you ever get a chance to see brand new cars that have just been delivered to the dealership ( before the centre disc caps are fixed ) you'll be shocked at how much surface rust has gathered.

 

Check out this review of a  +£100k Audi.   Audi RS6 long-term review  Even their ceramics act like rust magnets!

 

Of course all manufacturers suffer from this problem, but if my experience is anything to go by, VW group wins the race for the fastest build up of surface rust.

 

 

This is my experience. Have had a MkIII Octavia, an A6, now a Kodiaq (and the Mrs's Touran) and the stock discs seem to attract rust faster than any other make we've had.

 

I love the cars and doubt I'd change from VAG given the overall experience we've had generally with them but what you say definitely rings true. 

[Ootohere]

As to Rust / Corrosion & Discs Calipers, it is winter season coming in and not is all equal around the UK and in my area Gritters were out the other morning, 

That is Salt / Grit, and that is not the same around the UK.

 

You might notice with some vehicles that are parked roadside that the Drivers side can be worse than the passenger side for corrosion or dirt if you park passenger side to the pavements.