Substandard brake discs

[markjay]

As others said there are many factors that determine wear rate - mileage isn't everything, it's how many times you actually apply the brakes - a short distance driven through back streets littered with speed humps will cause more brake wear than a longer motorway cruise etc.

But in addition, I would argue that brakes are like tyres: wear rate is a factor that has a trade-off with other factors. It obviously depends on how the pads' material mate with discs' material, as well as the operating temperatures.

Short service life is a feature, and not necessarily one that can be referred to as 'substandard'.

You may well argue that you had no use for the features that were (potentially) enhanced at the cost of higher wear rate (perhaps, better resistance to fade? Etc), but the implication is that perhaps we should be researching brakes' performance including wear rate, in the same way that we look at tyres, to ensure that we buy the correct product for our needs.

 

[219]

As others said there are many factors that determine wear rate - mileage isn't everything, it's how many times you actually apply the brakes - a short distance driven through back streets littered with speed humps will cause more brake wear than a longer motorway cruise etc.

But in addition, I would argue that brakes are like tyres: wear rate is a factor that has a trade-off with other factors. It obviously depends on how the pads' material mate with discs' material, as well as the operating temperatures.

Short service life is a feature, and not necessarily one that can be referred to as 'substandard'.

You may well argue that you had no use for the features that were (potentially) enhanced at the cost of higher wear rate (perhaps, better resistance to fade? Etc), but the implication is that perhaps we should be researching brakes' performance including wear rate, in the same way that we look at tyres, to ensure that we buy the correct product for our needs.

A most erudite post

 

[wongl]

In London traffic, I find that the front pads would last circa 12k to 15k miles on several different models of Mercedes (A, C, and E). The discs tend to last two sets of pads, so typically 24k to 30k. The rears tend to lasts twice as long as the fronts.

This is due to mine and my family's driving style. Mileage on others would probably vary.

 

[dmb007]

At service at a main dealers more than a year ago I was advised that disks and pads needed replacing.

Due to other problems changed my dealer.

Just had another service at that new main dealer and no mention of replacement of disks and pads.

So asked them about this because of advice previous and told no problems with disks or pads.

Car as done 54,000 miles.

I would expect the pad wear indicator to show if pads needed between services.
Also I try not to use my brakes.

Regards
David

 

[markjay]

At service at a main dealers more than a year ago I was advised that disks and pads needed replacing.

Due to other problems changed my dealer.

Just had another service at that new main dealer and no mention of replacement of disks and pads.

So asked them about this because of advice previous and told no problems with disks or pads.

Car as done 54,000 miles.

I would expect the pad wear indicator to show if pads needed between services.
Also I try not to use my brakes.

Regards
David

An honset dealer will simply tell you what percentage are the pads worn. This is what I am told at MB Brooklands after each service.

Waiting for the pad wear indicator to illuminate is fine for some, but not everyone is happy to rebook the car in at a later date especially if the dealer isn't local to them.

So the dealer should provide the facts, it's then down to the owner to decide what they want to do.

But certainly I think it's good practice on the dealer's side to draw the owner's attention to any service item that is still serviceable now but might not last until the next service is due.

 

[dmb007]

The first dealer said I needed to replace
The second dealer at last service did give me percentages
I only do about 4k a year so I am happy to leave till next service

 

[wongl]

I used to own a Mazda which I had serviced every three months or so (due to the high mileage I was doing) at a not so close Mazda dealership. During one service I got a phone call informing me that the front rubber gaiters needed replacing a price of £1200. I declined after checking with my local MOT garage who quoted circa £400 to replace the gaiters on both sides of my Mazda.

I booked it into my local MOT garage and was very disappointed when I went to collect my Mazda to be told that they didn't replace the gaiters because it wasn't necessary.

For the next six years, at the annual MOT for the Mazda, the MOT inspector would make a point to bring me into the garage to show me that the rubber gaiters were still fine!

An honest garage is hard to find, but when you find one, stick with them! Needless to say I take all my cars to this garage for their MOTs.

 

[CaptainBirdseye]

I've had my E220 for exactly a year. Hadn't driven it for almost 4 months due to lockdown. After approximately 14k miles, brakes began screeching. During the first service 2/3 weeks ago, the staff at MB Croydon said that the brake discs and two front tyres were quite worn, though not to the extent that they were illegal. It matters not that during my driving career (36 years), I have not experienced - on any vehicle that I have driven - the tyres and discs being worn down so quickly (less than 30k miles). I have researched and asked those that are knowledgable about these things; I've been informed that the discs should last between 30k and 70k and as I said, that's what my experience tells me too. Now, I know that it obviously depends on how the vehicle is driven, even before I've been told this 3/4 times by various MB staff/technicians like I'm an idiot. I work as a chauffeur and I'd be a terrible one that didn't get much work if I did not drive very carefully, so please do not tell me it's down to the way I drive. The way I drive gives Hoke Colburn a run for his money (he's the chauffeur in Driving Miss Daisy), and driving as I do, the discs should not even be looked at before 60k in my opinion - especially on a £35-40k car.

Just had my 6 year old c220 in for a service at 54000 miles. On service at 4 years old and 40000 miles with the same dealer MB Aberdeen I had discs and pads renewed. This time I am told that my rear discs are slightly corroded and that this corrosion will not come off on driving the car. I am also told that the front discs are less corroded however that should come off on driving the car. Recommendation is to have the rear discs renewed along with the pads which still have 6 mm of available wear left. It is advisable to renew the pads with new discs so they say. On running my finger over the face of the discs it feels like the corrosion/scoring is limited to thousands of an inch.

Of course I said no and duly got my MOT certificate and advised that I shall need to replace the discs on my next MOT.

Feels like a complete con and the way that MB are charging now time for a change.

Anyone aware of any issues that may occur if you go to a local non MB dealer to get your car serviced.?

 

[SlimJim]

No issues, search out an independent Mercedes or German marque specialist. MB Aberdeen is Arnold Shark I believe, enough said.

 

[CaptainBirdseye]

No issues, search out an independent Mercedes or German marque specialist. MB Aberdeen is Arnold Shark I believe, enough said.

Thanks for that.

 

[ernie]

No issues, search out an independent Mercedes or German marque specialist. MB Aberdeen is Arnold Shark I believe, enough said.

...And so is Grangemouth! When my car was serviced by them in January, I left a set of rear pads to be fitted if necessary as they looked near end-of-life. They didn't fit them saying discs and pads OK for the moment and to wait till the wear light comes on.

In the past, I've found G/M to be honest with reasonable costs. However, they would have charged me an hour (~£160.00)
for the rear pads this time had they fitted them. Previously I've been charged half an hour when the car was in for service anyway. I also notice that they will do 'AC Approved discs and pads' at a rate that is less than the MB rate.

Presumably AC is feeling the Covid Pinch!

Ernie

 

[zipdip]

This thing with brake disc's can be very annoying,some years ago I took my car in for a service and MOT,the garage was quiet near to where I lived,I said I would come back around 5 pm,I had been working about 15 hours so dropped the car off and went to bed 4 hours later I get a phone call from the garage your rear disc's are rusty,so I got up went round and the young mechanic showed me the edge of the disc;s where you get rust,I was not amused,I remember saying the disc's are cast iron they do rust where the pads are not in contact plus a few choice words,service and mot in hand I never went back to them again,maybe they try this because so many car owners know next to nothing about a car.

 

[suty455]

as has been suggested already if your car has been sat for some time it may well need new discs and possibly tyres as they may flatspot, my wifes car was virtually unused for almost 6 months last year only has 26k on it but it had to have discs replaced due to rust contamination of both the discs and pads, rears were the worse where the handbrake was clamped on , cars are meant to be driven

 

[Silverarrows]

Agreed!

Most things from China are made of shit!
Falls apart or degrades and is not made to last.

Finding a quality manufacturer nowadays is difficult, but they do exist.
Lemforder, an OEM manufacturer to Daimler Benz is one, their parts actually perform and last!

My father used to say:
"The quality will be remembered long after the price has been forgotten"

 

[merc estate]

Have you tried bending down and looking at them, i know all you see is not true but it would give you an idea. I have been told things in the past needed doing on other cars, one mot said i needed new hand brake shoes on an e class which i told them not to do, they gave me the mot, i had that car another 7 years with the same garage doing the mot and they never said it again.
Only trust the person you see in the mirror. A rule of thumb, when having a service or mot i have a check around lights wipers tyres brake pads and discs it takes 2 minutes.

 

[Fastcar155]

Thanks for the advice guys, but this is not the issue. I cannot accept that the discs are almost worn to the point of replacement because I've now done only 19k miles and drive very carefully. Especially when I look back and remember before I became a chauffeur, oftentimes driving like Hamilton Lewis and still not having to replace brakes before (in the worst case) 35k. I feel these days big corporations / manufacturers deliberately use inferior parts so they need to be replaced sooner. I replaced my mums 35 year old washing machine 13 years ago - had 4 new ones since! Fridge, TV, car, etc. All made of shit nowadays.

Programmed to fail!

 

[Tonygw]

Its quite easy to check them your self, poke a torch through a space in the alloy wheel, you will see the pads and how much is left of them, to check the disc, run your finger up the front surface to the edge, if you feel a massive lip at the edge they are worn, if its a small lip they are fine, this is quite normal. This is not a very scientific method I know, but its a very good indicator and one I use as I have changed well over 50 sets of discs and pads on cars over the years. I only change the discs and pads on our cars when the discs have a big lip on them, severe rust around the edge and the pads are getting close to the metal. Of course, Mercedes do have pad wear indicators built in to the pads which will tell you when they are worn. In my experience when the brake pad indicator illuminates, you have literally thousands of miles left if you go easy on the brakes. Obviously hash braking will wear them down much quicker. You can see where the sensor fits into the pads they are way off the backing plate.

Dealers will try to sell you brakes as its easy money for them. But chances are they are fine for quite some time yet.