Brake disc corrosion

[Sandyvan]

Bagman Jim do you have any photos?

 

[Mike Maguire]

We are currently having an air-con service and idler pully changed, the later is the latest recall apparently. During the free vehicle health check the technician has said the rear brake pads have considerable corrosion (something I had noticed earlier) and they are saying the discs and pads could be replaced at a cost of £275.00 plus VAT. Now our Cali is just two years old and has less than 7000 miles on it. I feel this is a warrenty job but brakes are not covered even though in my opinion the brake discs must be inferior to be in the state they are. The vehicle has never seen road salt and I appreciate that not using a vehicle isn't ideal but I find this unacceptable.
Before anyone comes on here and berates me for not using the Cali for what it was designed for I was diagnosed with bowel cancer shortly after buying it and am currently undergoing chemo which really cramps your style!

Rust on the outer edge of the rotors is a standard outcome since the disc pads do not cover the outer edge. Yes, you could get a fair bit of rust on the swept areas, but at 7k mileage the disc MM wear from braking would be minimal & first thing to do would be to drive & after initial caution use the brakes with periods of moderate braking at relatively high speed, check them for how much corrosion remains on the swept areas, then similar with heavier high speed (70) braking & then recheck. I& there is still a fair amount of corrosion on the swept area consider replacement. A heavily laden Cali needs effective rear brakes & especially if for any reason the brake servo fails or there is a failure of the brake hydraulics and the handbrake & gears are all you have left to depend on ... God forbid!

Unfortunately, persuading customers to approve “early repairs & replacements”:, or ”up-selling” as it’s called in the trade, is a not uncommon feature!

Very best wishes for your health recovery.

 

[WelshGas]

Front Discs replaced at 77,000 miles due to scoring on the inside face of both discs. Rear Discs fine.
77k miles in 4 years.

 

[Mike Maguire]

From my brief days with metalworking I was told that cast iron is very rust resistant. Milder steel with a higher Friction coefficient was introduced wi5h 5ge removal of asbestos from pad manufacture.

Must correct myself! The comment was regarding wrought iron! Cast iron is too brittle fo hammers etc. & yes, the discs are cast iron. Far less likely to warp!

 

[Legin]

From my brief days with metalworking I was told that cast iron is very rust resistant. Milder steel with a higher Friction coefficient was introduced wi5h 5ge removal of asbestos from pad manufacture.

The discs are indeed cast iron not steel as stated. Steel would make a poor disc brake. What has changed is the grade of cast iron to a lower grade. The last car I had with quality factory CI discs was my R129 mercedes still going strong after 5 years irrespective of the use, everything I have owned since then is lower quality. Doesnt apply to motorbikes btw.

 

[Mike Maguire]

The discs are indeed cast iron not steel as stated. Steel would make a poor disc brake. What has changed is the grade of cast iron to a lower grade. The last car I had with quality factory CI discs was my R129 mercedes still going strong after 5 years irrespective of the use, everything I have owned since then is lower quality. Doesnt apply to motorbikes btw.

Makes me wonder if the poorer grade cast iron also applies to quality aftermarket discs ... e.g. Brembo or Pagid? & whether they do road rather than track grade pads?

 

[Legin]

Makes me wonder if the poorer grade cast iron also applies to quality aftermarket discs ... e.g. Brembo or Pagid? & whether they do road rather than track grade pads?

Certainly does. The likes of Alcon and AP are where the quality is but not cheap.

Track pads are not suitable for road as they are designed to work at much higher temperatures so road and track have always been different compound.

 

[flying banana]

Get it on a brake force machine. If it passes leave them. All discs rust from the outside edge. Especially rear ones as they take less of the braking force that the front do. 80 percent to 20 percent I believe. You could reverse hard and brake a few times. Might clean em up a bit. Don't new pads come with a layer of polishing material for initial use to help clean the disc ?

 

[Snowball1935]

My Caravelle now has 17042 miles on the clock. At last year’s service the VW technician said my brake disc(s) were corroded - he didn’t say which ones or how many - and replacement costs were quoted at around £600.
When I pointed out that, except in the “swept areas”, brake discs do corrode, he said it was in the swept area.
I know that during standing the discs can produce a slight oxidation of the swept surfaces, but this will be cleaned away next time vehicle is driven. Also, during wet weather, when on the move centrifugal force will drive water away from the discs, and even with moderate braking discs do become hot, so any water or dampness on the discs will vaporize.
My 09-plate Touran, at 55,000 miles and 9-years-old still had the original discs, and they were still bright clean.
If the swept area of a disc becomes pitted with rust, then that is likely to be due to failure of pad to engage disc (seized brake assembly piston?), which could be identified by unusually thick pad compared to other pads. This fault could not be expected to be general on a properly serviced vehicle, without significant experience of loss in braking power.
So for the obvious question, “is the technician trying to generate a sale by falsifying the state of my brakes?”
I have been with this dealership for over 20 years but, since owning the Caravelle, I have not been fully comfortable with the commercial side of the business. Opinions would be appreciated.

 

[PIERPO]

We are currently having an air-con service and idler pully changed, the later is the latest recall apparently. During the free vehicle health check the technician has said the rear brake pads have considerable corrosion (something I had noticed earlier) and they are saying the discs and pads could be replaced at a cost of £275.00 plus VAT. Now our Cali is just two years old and has less than 7000 miles on it. I feel this is a warrenty job but brakes are not covered even though in my opinion the brake discs must be inferior to be in the state they are. The vehicle has never seen road salt and I appreciate that not using a vehicle isn't ideal but I find this unacceptable.
Before anyone comes on here and berates me for not using the Cali for what it was designed for I was diagnosed with bowel cancer shortly after buying it and am currently undergoing chemo which really cramps your style!

 

[B J G]

Makes me wonder if the poorer grade cast iron also applies to quality aftermarket discs ... e.g. Brembo or Pagid? & whether they do road rather than track grade pads?

There are various grade pads available. eg Green stuff do ones suitable for road-fast road/competition - Race. Discs have become ,softer, after asbestos was banned from pads as non asbestos content pads have less friction-stopping power on the harder discs.
Higher spec pads usually don't have low speed efficiency so wouldn't be advisable on a Cali.
Whether pads are available for the Transporter range I haven't looked as yet.
Higher quality discs usually have a recommended pad to use.

 

[Snowball1935]

I would say Yes. Discs build up surface rust very quickly if a van is not used every day as they are exposed to the elements. Just take it on hilly run and give them some use.

Did it come as an advisory on last MOT?

The service department use a traffic light system, and the Health Check showed RED on this report, but there was no advisory on the MoT.
When I questioned the technician (by phone) he sent me a photo on my phone. It was not very clear, as it was a view taken through the wheel spokes. This puzzled me because, if there was anything significant, surely this snapshot should have been taken with the wheel removed.
I take the point about a vehicle standing for a few days, but I don’t think there is a significant exposure to the elements. I previously mentioned discs drying quickly because of being hot at the end of a journey (even a short one), and the vehicle standing in the open will usually suffer less humidity than one put into a garage when still wet.
The vehicle goes in for its annual service on June 1st - next Wednesday - so will see how things go in the next few days.

 

[Tim T]

So for the obvious question, “is the technician trying to generate a sale by falsifying the state of my brakes?”

No, it's just modern brake discs I'm afraid. They are sacrificial like brake pads and not under warranty and work fine if used as a commercial T6 is normally used - every day.

If your calipers were seized they would be seized "ON" and you'd know about it.

Honestly I think you're over thinking this, I've a T6 at 45K and am on my third set of rear discs. Leave it unused for a couple of weeks, especially after a winter trip and the discs will rust, and because of the brake balance the rears seem to take a good while to clear, (unless you drive a few miles with the handbrake on or do emergency stops at every junction). This rust seems to form a grinding "paste" which sets grooves in the rear discs and basically wrecks them. Either the grooves reach minimum thickness well before time or you're faced with new pads that take a long time to "bed in".

They have to be replaced as a pair.

I'm now out of warranty so if I need to replace the rear discs again I will NOT be going for "genuine" VW spares as I can't see the performance of after market spares being any worse. ;-)

P.s. My discs fair better, (less rust) if I garage the camper when not in use for a week. Don't ask me why, it's just an observation. I garaged the van after the first rear discs expired at 10K.

 

[Snowball1935]

Hi, Tim T,
Agree with your point that a seized caliper would be seized ON.
Your experience of a third set of rear discs at 45K does surprise me. I would expect wear to be similar to my previous VW Touran - 55K on clock at 9-years old, and still OK at final service during my ownership. Caravelle is used under same conditions as the Touran. Caravelle is not truly a “van” - V5 classes it as a diesel car, and insurance companies rate it as either a large MPV or a large estate car.
We always yearned for a Caravelle (being caravanners), but I’m afraid our enthusiasm is going a bit off the boil. “We buy any car.com” have rated the value of the Caravelle at £28,700, so selling it is a temptation.
The COVID situation plus my having vascular surgery on my leg (lucky not to lose it!), my active ability has been very much restricted, and we have considered changing to a small motorcaravan. Hard to finally decided, though!

 

[WelshGas]

Hi, Tim T,
Agree with your point that a seized caliper would be seized ON.
Your experience of a third set of rear discs at 45K does surprise me. I would expect wear to be similar to my previous VW Touran - 55K on clock at 9-years old, and still OK at final service during my ownership. Caravelle is used under same conditions as the Touran. Caravelle is not truly a “van” - V5 classes it as a diesel car, and insurance companies rate it as either a large MPV or a large estate car.
We always yearned for a Caravelle (being caravanners), but I’m afraid our enthusiasm is going a bit off the boil. “We buy any car.com” have rated the value of the Caravelle at £28,700, so selling it is a temptation.
The COVID situation plus my having vascular surgery on my leg (lucky not to lose it!), my active ability has been very much restricted, and we have considered changing to a small motorcaravan. Hard to finally decided, though!

I'm afraid it doesn't matter what the Caravelle is registered as. It is based on a Transporter, a commercial vehicle and has basically the same mechanicals, engine, suspension, drive train and brakes. Commercial vehicles are normally used everyday and certainly rarely parked for days,weeks or months at a time.
On my California the brake pads were changed at 77,000 miles as they were down to 10-15% and I was going on a 6000 mile Scandinavian driving holiday. The front disks had some scoring on the inside surfaces so I decided to have them changes because scored disks and new pads mean decreased braking efficiency until the new pads have adapted to the scored surface. My California tends to be used everyday, is kept outside 24/7 and the longest time it has been idle is 5 weeks at Heathrow Long Stay carpark when visiting my son in Australia.
A normal " Car " tends to be used most days for short journeys compared to a "Commercial " based vehicle such as a Caravelle or California especially if they are not used as a Daily driver.
The old saying " Use it or Lose it " springs to mind.

 

[Tim T]

Your experience of a third set of rear discs at 45K does surprise me. I would expect wear to be similar to my previous VW Touran - 55K on clock at 9-years old, and still OK at final service during my ownership. Caravelle is used under same conditions as the Touran. Caravelle is not truly a “van” - V5 classes it as a diesel car, and insurance companies rate it as either a large MPV or a large estate car.

I still think you're looking in the wrong place here rather than seeing the obvious, if you will excuse me saying...

My California is on it's third set of rear discs, fact. The first set went when we had another car and the van sat on the drive after a winter trip, the second set went after covid and the van again sat not being used much.

It happens and is not an isolated experience. But... They are discs and are sacrificial just like the brake pads and excessive wear is simply NOT covered under the warranty. Being that VW have no trouble with the Transporter these vehicles are based on there is no real incentive to really do anything about it. No amount of reasoning is going to change this, neither is the listing on the V5 which refers to use and not construction as your Caravelle is a Transporter chassis with seats and windows.

The problem may very well go away if you fit aftermarket parts through an "approved" service provider, I can pretty much guarantee it won't if you fit genuine VW spares.

Lots of vehicles have weaknesses, the Transporter/California/Caravelle has soft rear discs prone to rust when not used very often. But they are designed to wear out at some point, so just replace them with different ones like Bembros.

The Bridgestone tyres I got as OE on my California are not really suited to the van either, upgraded SUV tyres with weak sidewalls, slightly too wide, and soft for a heavy front wheel drive van that seems to have a front brake bias. I bet their inclusion was a budget decision based more on price than engineering. They wore out in 10K too, I have different tyres now more suited to a van...

The VW service centre tends to measure the discs for minimum thickness, I think the MOT just inspects tests the efficincy and advises.

 

[Snowball1935]

A VW Caddy is a commercial vehicle, but is based on the Touran. Regardless of class (private or commercial) the general specification of the mechanics is common to either. From a commercial point of view, certain components will be more robust - suspension, tyres, brakes and the like. A vehicle doesn’t “know” what working life it is designed nd, in fact, a commercially-based vehicle will have many of its components designed to deal with a rougher life than a private vehicle. Also, the longevity of components will not become shorter for a commercially-based vehicle just because it works in a private-use environment. Large motor homes are built on commercial chassis and are generally known for their very low mileage and stationary time over a number of years, but they do not have a history of critical and mechanical deterioration as a result of lengthy periods of idleness.
I do not have a second vehicle, so my Caravelle suffers no more idleness than a standard motorcar where retirement results in a much lower annual mileage.

As I have said, my Caravelle is registered as a diesel car, insurance companies class it as either a large MPV or large estate car. I did once explore the possibility of insuring it as a van, for the purpose of cheaper premium, but insurers refuse to accept a van classification.
In fact, VW only include Caravelles and Californias in their commercial vehicle range because it suits their production line arrangements.

 

[WelshGas]

A VW Caddy is a commercial vehicle, but is based on the Touran. Regardless of class (private or commercial) the general specification of the mechanics is common to either. From a commercial point of view, certain components will be more robust - suspension, tyres, brakes and the like. A vehicle doesn’t “know” what working life it is designed nd, in fact, a commercially-based vehicle will have many of its components designed to deal with a rougher life than a private vehicle. Also, the longevity of components will not become shorter for a commercially-based vehicle just because it works in a private-use environment. Large motor homes are built on commercial chassis and are generally known for their very low mileage and stationary time over a number of years, but they do not have a history of critical and mechanical deterioration as a result of lengthy periods of idleness.
I do not have a second vehicle, so my Caravelle suffers no more idleness than a standard motorcar where retirement results in a much lower annual mileage.

As I have said, my Caravelle is registered as a diesel car, insurance companies class it as either a large MPV or large estate car. I did once explore the possibility of insuring it as a van, for the purpose of cheaper premium, but insurers refuse to accept a van classification.
In fact, VW only include Caravelles and Californias in their commercial vehicle range because it suits their production line arrangements.

1. You cannot change the M1 or N1 classification on your V5c so Insurance companies will not change.
2. Caravelle, California Ocean/ Beach, Shuttle, Kombi, Van with Windows or plain Transporter Van are all built on the same production line and have the same engines, drive train etc only varying if they are T28/30 or 32 which relates to the MGW of the vehicle and with different trim levels Startline, Trendline, Highline, Sports line, Beach, Ocean, Caravelle , Shuttle.

 

[Tim T]

Actually other motor homes do suffer rear disc problems from lack of use.

Snowball, I agree with you, the rear discs on a VW transporter/etc. do seem fragile. I am surprised at the wear that occurs once you let them rust. But I'm also surprised at just how well they work when in specification. It's a heavy van, the brakes work harder than they do on an SUV.

I don't want to argue over it, and that's my whole point. You can drive yourself blue in the face but there is little you can do about it because VW will not cover excessive wear of brakes under warranty, they do not see it as a problem with the van but one with your specific usage. I kinda agree with them, in a way...

Your discs need changing, that is fact as VW will not be lying to you. You will have to pay for it, (they were going to need changing at some point anyway at your expense), so put some different ones on.

VW include Californias/Caravelles in their commercial range because they are Transporter based and so the car dealerships are not equipped with the training, familiarity and special tools to service them.

 

[Jay586]

I live at the seaside, both my vehicles get rusty discs almost immediately on standing.

 

[Volkywagen]

Also stay away from those drive through car washes as the guys use an acid to clean brake dust off wheels which corrodes the discs and speeds the process up

 

[Snowball1935]

Well, there’s a surprise! Caravelle went in for its annual service. Under their traffic light system, health check showed amber for rear brake pads to be changed at next service. No advisories on MoT.
As for the supposed “brake disc corrosion”, not a mention of this for this service.
Timing belt change, plus water pump, was about £450, and receptionist told me it will be £750 next time !!! They must plan their increases well ahead.
That will be 5-years forward, and current service plan will have expired. Am considering another independent VW garage - our daughter changed her VW camper service from VW franchise to this garage due to dissatisfaction, and our son’s neighbour has been taking his VW to this garage for years, and he’s fussy over his cars.

 

[Perfectos]

Well, there’s a surprise! Caravelle went in for its annual service. Under their traffic light system, health check showed amber for rear brake pads to be changed at next service. No advisories on MoT.
As for the supposed “brake disc corrosion”, not a mention of this for this service.
Timing belt change, plus water pump, was about £450, and receptionist told me it will be £750 next time !!! They must plan their increases well ahead.
That will be 5-years forward, and current service plan will have expired. Am considering another independent VW garage - our daughter changed her VW camper service from VW franchise to this garage due to dissatisfaction, and our son’s neighbour has been taking his VW to this garage for years, and he’s fussy over his cars.

If you have an independent garage that you trust and can build a relationship with, I see no reason to not to use them.

even during warranty period you can use A.N. other to carry out the work,
VW cannot legally insit that the work is carried out by the VW network (many of whom are Franchise businesses who operate under the VW name, but in reality are only flying the VW flag at a price so to speak )

the only catch to using an indie within warranty period (using vw OEM parts and sticking to the VW service schedule / regime) is they (the indie) must be Vat registered (don’t ask why) for VW to recognise the garage Whom maintained the vehicle.

 

[Resfeber]

The service department use a traffic light system, and the Health Check showed RED on this report, but there was no advisory on the MoT.
When I questioned the technician (by phone) he sent me a photo on my phone. It was not very clear, as it was a view taken through the wheel spokes. This puzzled me because, if there was anything significant, surely this snapshot should have been taken with the wheel removed.
I take the point about a vehicle standing for a few days, but I don’t think there is a significant exposure to the elements. I previously mentioned discs drying quickly because of being hot at the end of a journey (even a short one), and the vehicle standing in the open will usually suffer less humidity than one put into a garage when still wet.
The vehicle goes in for its annual service on June 1st - next Wednesday - so will see how things go in the next few days.

The service department use a traffic light system, and the Health Check showed RED on this report, but there was no advisory on the MoT.
When I questioned the technician (by phone) he sent me a photo on my phone. It was not very clear, as it was a view taken through the wheel spokes. This puzzled me because, if there was anything significant, surely this snapshot should have been taken with the wheel removed.
I take the point about a vehicle standing for a few days, but I don’t think there is a significant exposure to the elements. I previously mentioned discs drying quickly because of being hot at the end of a journey (even a short one), and the vehicle standing in the open will usually suffer less humidity than one put into a garage when still wet.
The vehicle goes in for its annual service on June 1st - next Wednesday - so will see how things go in the next few days.

I too have been down this road so to speak.
Cali passed its first MOT last year at 26k with an advisory for rear disc corrosion (after a bit of huffing and puffing about whether to fail)

The original VW discs had been like this almost from day one (bought at 7 months old Jan 2019) and used as daily driver just about.
We are a mile or so from west coast in Cumbria and a shining disc changes colour to rust yellow in a few hours with a south westerly blowing at us, even though reasonably sheltered.

Replaced with Brembo pads and discs.
V Happy with result (now + 10k and MOT pass no advisory ) distinct extra bite under sustained braking (currently on NC500).

 

[Snowball1935]

Also stay away from those drive through car washes as the guys use an acid to clean brake dust off wheels which corrodes the discs and speeds the process up

I assume you mean the “hand wash” type of operation. I used to use the automatic car wash when I had my Touran, but haven’t used one for my Caravelle as Sainsbury’s (my usual wash centre) had a notice banning transit-sized vehicles; due to, I believe, an incident where such a vehicle became fouled up with the rotating brush mechanism.