The great rear brakes con....

[Jamboneil]

I have two MG's, a 2020 ZSEV and a 2024 HS Hybrid.

In June of this year, my 5 year old ZSEV was getting it's annual service and I was informed that the rear discs were badly corroded and they and the pads needed replaced. A quotation for around £440 was offered.

Yesterday, my 1 year old HS Hybrid with 8000 miles was in for it's very first service. I was informed that the rear discs are badly corroded and need replaced.
I haven't had the quotation yet but I have had emails and texts saying that they have identified "Urgent work required" and to book an appointment with them!

Is this just a Vertu revenue generation thing or are other dealers doing it?
Is it that the cars are very reliable and there's very little for the service staff to do, so they make things up?
Or.... are the rear brake discs and pads really so bad they need replaced every 8000 miles?

 

[JohnV6]

It is very unlikely you need discs & pads at 8k. Get a second opinion at a good local private run garage.

 

[Alb]

It's not a subject you can really generalise on. It's possible for corrosion to occur at low mileage through lack of use but it isn't inevitable. Upload some pics of your disks and you can get some independent opinion.
My last car (MG5) was low mileage (14K) when I sold it at 4 years old and the disks were perfectly fine.
MG disks don't often look that good from a cosmetic perspective because I think they use a low grade of steel.

 

[Bradmore]

I have my first MG an HS Hybrid+ now with 300 miles on the clock. I have been looking at all the posts from members about the trial and tribulation they are having with their MG's
Overcharging, dealers who look on customers as a necessary evil, and poor materials used in the manufacture, ie brake discs. Am I only seeing the negative side of owning an MG or are there members out there who are more than happy with their cars, MG, and dealers?
My feeling is to get rid of my MG whilst I can. These posts certainly make dismal reading.

 

[Slipstream]

I have two MG's, a 2020 ZSEV and a 2024 HS Hybrid.

In June of this year, my 5 year old ZSEV was getting it's annual service and I was informed that the rear discs were badly corroded and they and the pads needed replaced. A quotation for around £440 was offered.

Yesterday, my 1 year old HS Hybrid with 8000 miles was in for it's very first service. I was informed that the rear discs are badly corroded and need replaced.
I haven't had the quotation yet but I have had emails and texts saying that they have identified "Urgent work required" and to book an appointment with them!

Is this just a Vertu revenue generation thing or are other dealers doing it?
Is it that the cars are very reliable and there's very little for the service staff to do, so they make things up?
Or.... are the rear brake discs and pads really so bad they need replaced every 8000 miles?

EV brakes tend to look corroded especially rears. They don't get the same use as ice cars. I brake really hard several times a week. This cleans all the rust and corrosion from the discs.

 

[LeedsLoiner]

My ZS is now 8 months old with low mileage which I expected would have some rust and corrosion. I had a look a few days ago and was pleasantly surprised to see that all discs were clean and shiny.
I am probably one of many very happy owners with nothing bad to say about our MG's.
It would get very boring reading my MG is running fine, or sorry, once again, nothing to report.
I'm sure yours will be fine too. Stop worrying and just enjoy it.

 

[MonkeyM]

Please take the car to any independent car repair/tyre place for a second opinion. Dealers are not called “Stealers” for nothing. And brakes/pads are not EV specialist items. Even if they do need replacing it may well be cheaper.

 

[Davlor]

I have my first MG an HS Hybrid+ now with 300 miles on the clock. I have been looking at all the posts from members about the trial and tribulation they are having with their MG's
Overcharging, dealers who look on customers as a necessary evil, and poor materials used in the manufacture, ie brake discs. Am I only seeing the negative side of owning an MG or are there members out there who are more than happy with their cars, MG, and dealers?
My feeling is to get rid of my MG whilst I can. These posts certainly make dismal reading.

I have had my MG HS hybrid for 8 months it’s done 9000 miles and I am very happy with it. People don’t tend to come on these forums just to say things are fine so you will only see the negative comments. Valid as they are it’s just a small percentage of car owners. Note what’s said but don’t worry - every make and model of car have issues of one type or other.

 

[Bradmore]

It would be great to have trust in car dealerships when we have bought a car from them, and for them to hold our hands during the entire car ownership period, making any problems less of a pain.
In the real world it's not going to happen.
If we need a new car in almost all cases we have to go to a garage with the franchise, most of which take very little interest in us as customers after the sale.
I have been buying cars mainly from new for the last 70 yrs ( yes you read it right 70 years) and I haven't found a main dealer yet who shows a great deal of interest in a customer. Maybe I have been unfortunate. My answer has always been not to buy from them again. Hence why I have bought my first MG, my last car was a Ford, but that's another story. After reading the posts it looks like I may have jumped out of the frying pan into the fire. Time will tell. It may well be my last car purchase anyway. Old age and poverty.

 

[kc1966]

I have my first MG an HS Hybrid+ now with 300 miles on the clock. I have been looking at all the posts from members about the trial and tribulation they are having with their MG's
Overcharging, dealers who look on customers as a necessary evil, and poor materials used in the manufacture, ie brake discs. Am I only seeing the negative side of owning an MG or are there members out there who are more than happy with their cars, MG, and dealers?
My feeling is to get rid of my MG whilst I can. These posts certainly make dismal reading.

I bought a mg4 new nearly 2 years ago. Car is brilliant no problems and the dealer has been great. I had a puncture they were the best price and quickest for a new tyre. At the service the software was updated without asking making it an even better car.

It’s an ev with regen. The brakes don’t work nearly as hard as an ice car. Just use the brakes hard when going downhill and no one is behind.

 

[agb]

I have my first MG an HS Hybrid+ now with 300 miles on the clock. I have been looking at all the posts from members about the trial and tribulation they are having with their MG's
Overcharging, dealers who look on customers as a necessary evil, and poor materials used in the manufacture, ie brake discs. Am I only seeing the negative side of owning an MG or are there members out there who are more than happy with their cars, MG, and dealers?
My feeling is to get rid of my MG whilst I can. These posts certainly make dismal reading.

Brakes need friction and to get that a SOFT (some might say "low grade") steel is used . This corrodes instantly. Splash water on a hot dry disk and watch it go brown ( not joking, try it).
Corrosion is NOT like wood rot. The reddy-brown ferric oxide is an inert compound which forms a protective coating (with aluminium oxide it absolutely does stop corrosion).
So all in all, seeing rusty brakes discs is nothing ever to worry about.
Now.
I have had an MoT tester try to fail my 205GTi on the brake discs. He picked the wrong guy. So after I tied him in knots with materials science, he gave up and agreed to pass the car. Which is my way of throwing suspicion on the need to replace the discs.
And the price.....
ICE discs and pads are £120 to £150 discs + pads a set. So why £400? Seems expensive.

All in all I would relax.

PS MG4 Trophy 1 year, 12000 miles. One of the best cars I have owned.

 

[Lucky1]

I own MG ZS EV LR 2022, it has 112,500km, the brakes are original I was told and when my mechanic was dealing with tires I took some pictures to inspect the brakes later. Discs are almost as good as new and brake pads are also not bad. Maybe the materials here were better but I doubt. I'll attach the pics for your reference.

 

[ddclutch]

I suspect that brake disc damage is not just corrosion but is caused in part by the disc picking up grit and dirt between infrequent application of the brakes. So when the brakes are then used that grit is caught under the pads and ground into the disc, causing scoring.

 

[Lovemyev]

I suspect that brake disc damage is not just corrosion but is caused in part by the disc picking up grit and dirt between infrequent application of the brakes. So when the brakes are then used that grit is caught under the pads and ground into the disc, causing scoring.

I do totally agree with this statement, but the rust / corrosion does play its evil part as well.
As the face deteriorates even more, parts of that surface of the discs, starts to get pushed up and then gets impacted into the face material of the pads, then when the disc passes through the pads, it cuts grooves in the surface of the disc.
There are photos on the forum of discs that are so bad, they have started delaminated.
ICE models fitted with similar material pads and discs, tend not to suffer this level of premature disc deterioration.
Only because the brakes are used more offered on an ICE.
High milage EV users appear to suffer less from this problem, but the opposite is true for low mileage users of course.

 

[Bradmore]

I think most of the conclusions regarding brake discs and corrosion on EV cars are valid. For what it's worth I have had ICE cars for 70 yrs, I have lost count of the number. Toyota, Ford, Range Rover, Audi, Volvo, Bradford Jowett, Rover, VW, Jaguar, to name a few and in all that time I have only ever had one set of front brake pads and that was on my low mileage Ford Edge, replaced this year, no replacement discs or drums at all. My MG is the first non ICE car I have owned. I think this probably leans towards the theory of the brakes being used less on EV cars. contributes towards the problem of early replacement of discs. I hope my story is of interest to this debate.

 

[EvTek23]

There was a general change of brake pad material some years ago, this was done to remove the harmful substances used in the composition of the pads. As a consequence the pad became harder, and to compensate the discs became softer and used more steel content.
In general in an ICE powered car you roughly get 2 sets of brake pad changes before the discs become too thin and they would need to be changed. An ICE car will use its rear brakes for more than an EV and keep the rear discs in good condition. An EV however uses far more regen for braking without using physical brakes. So unless you do higher mileage and use much more braking it is quite likely that the rear discs will become pitted by rusting etc rather than wear. I've seen on mine (MG4), that on short trips the surface rust that forms overnight only has a few bands that are clean on the disc due to the lack of use of the rear brakes.

 

[Bradmore]

There was a general change of brake pad material some years ago, this was done to remove the harmful substances used in the composition of the pads. As a consequence the pad became harder, and to compensate the discs became softer and used more steel content.
In general in an ICE powered car you roughly get 2 sets of brake pad changes before the discs become too thin and they would need to be changed. An ICE car will use its rear brakes for more than an EV and keep the rear discs in good condition. An EV however uses far more regen for braking without using physical brakes. So unless you do higher mileage and use much more braking it is quite likely that the rear discs will become pitted by rusting etc rather than wear. I've seen on mine (MG4), that on short trips the surface rust that forms overnight only has a few bands that are clean on the disc due to the lack of use of the rear brakes.

I agree entirely with your observations. It looks like something we will have to live with as EV's become more the norm. It is not a major problem to have new discs/pads, but most members raising the issue seem to be, understandably, concerned about the high cost of MG replacements and the scam which seems to be taking place. We all want things to last forever but it seems this is an issue where the type of vehicle/driving is dictating the need to replace more often. I suppose this is the price of the change in the type of cars we will be able to buy in the future.

 

[EvTek23]

@Bradmore, some manufactures certainly of ICE vehicles try to combat the relative lack of use of the rear brakes by fitting drum brakes. I always thought they just hadn't caught up with the times, but in reality they've researched the subject well and come up with a good solution. I think the Renault 4/5 EV's have drums on the rear and probably others too.

 

[Lovemyev]

@Bradmore, some manufactures certainly of ICE vehicles try to combat the relative lack of use of the rear brakes by fitting drum brakes. I always thought they just hadn't caught up with the times, but in reality they've researched the subject well and come up with a good solution. I think the Renault 4/5 EV's have drums on the rear and probably others too.

VW favour drums on the back for there FWD EV’s.
Wise move if you ask me.

 

[Bradmore]

VW favour drums on the back for there FWD EV’s.
Wise move if you ask me.

All manufacturers will have their own ideas and we don't know the reasons for their individual designs, we have to go with what is available. As we are concerned with our own costs of owning an MG at the moment, the cost of MG replacement discs and pads is certainly causing some concern for those members who have been advised that they need replacing.