MG ZS EV Brake discs

[Rabmc]

I wouldn’t worry too much as all discs gets scored. As long as they are not badly scored, worn or corroded. The effective area that the brake pads operate on is not really impacted by light scoring. the odd stone will always get stuck in there and score the disc. The worst enemy on EV’s is lack of use and seizing/rust. It is worth now and then giving the brakes a bit of a work out if your normal driving means that they get very light usage. Nothing too severe. As i previously mentioned it is also worth popping the brake pads out every couple of years and having a general clean up and regrease, depending on use and road conditions.

Anyone else got badly scored rear discs? My 2019 ZS EV discs are very badly scored, I think it's the hand brake pressure that's caused it. I took it to the dealer and showed him the worn rear discs and said I reckoned it was an mot failure. He did not disagree but said MG would not change the discs under warranty after the car was over 12 months old. The car has done 12000 miles. So much for the 7 year warranty!!!
Both rear discs are the same.

 

[Lovemyev]

Anyone else got badly scored rear discs? My 2019 ZS EV discs are very badly scored, I think it's the hand brake pressure that's caused it. I took it to the dealer and showed him the worn rear discs and said I reckoned it was an mot failure. He did not disagree but said MG would not change the discs under warranty after the car was over 12 months old. The car has done 12000 miles. So much for the 7 year warranty!!!

The lack of use of the foot brake as a result of Regen braking is the primary cause here.
75% of the braking on most ICE cars are conducted by the front brakes, but the rear brakes do get some work to do !.
In an EV the rears are doing very little.
Therefore, brake disc’s get prematurely replaced due to rust and pitting, rather than wear !.
I can see this being the focus of attention for dealers to bring in some extra income on EV’s - given that they need very little other intervention.
MOT stations will be on top of this as a failure point also.
A advise affect of the great Regen braking facility I think.
Brake pad friction material hardly touched, but the steel disc’s actually looking worse than they really are.
No sign of disc distortion or wrapping, but signs of pitting and scoring due to rust.

 

[Cocijo]

If you can, try to give your brakes a workout now and then. Brake in reverse also. It helps. Although irritating, brake discs are relatively cheap and easy items to replace when the time comes.

 

[macd2401]

Anyone else got badly scored rear discs? My 2019 ZS EV discs are very badly scored, I think it's the hand brake pressure that's caused it. I took it to the dealer and showed him the worn rear discs and said I reckoned it was an mot failure. He did not disagree but said MG would not change the discs under warranty after the car was over 12 months old. The car has done 12000 miles. So much for the 7 year warranty!!!
Both rear discs are the same.

Brakes are classed as wear and tear items in the warranty, so they only get 12 months cover. Most manufacturers will be similar.

 

[Kithmo]

If you can, try to give your brakes a workout now and then. Brake in reverse also. It helps. Although irritating, brake discs are relatively cheap and easy items to replace when the time comes.

Reversing definitely keeps them clean. I use my ZS every day and I live in a small cul-de-sac so I reverse out of my drive every morning, low speed, with my foot on the brake and apart from some very fine lines my discs are lovely and smooth.

 

[Rabmc]

Brakes are classed as wear and tear items in the warranty, so they only get 12 months cover. Most manufacturers will be similar.

I agree to a point but considering the brakes are hardly used because of the regen I think the rear discs are excessively worn for the mileage on the car. The front ones are fine. I had a Honda Accord for 12 years before my ZS and the discs were still good when I sold it.

 

[Lovemyev]

I agree to a point but considering the brakes are hardly used because of the regen I think the rear discs are excessively worn for the mileage on the car. The front ones are fine. I had a Honda Accord for 12 years before my ZS and the discs were still good when I sold it.

The Honda was not an EV so suffered no ill effects on the disc's / rotors from rust or scale being allowed to build up on the mating surfaces.
Brake disc corrosion is going to be an instant target for EV's at MOT time, I can already feel it brewing in my water .

 

[Gomev]

The Honda was not an EV so suffered no ill effects on the disc's / rotors from rust or scale being allowed to build up on the mating surfaces.
Brake disc corrosion is going to be an instant target for EV's at MOT time, I can already feel it brewing in my water .

Don't give them ideas....

 

[Lovemyev]

Don't give them ideas....

Your right of course.
A friend of over 40 years, that I served my time with a long time ago, has his own MOT / repair station with his older brother.
When I was there having my wife’s car MOT last year, he told me he has given up a long time ago, counting the number of MOT’s he has conducted in his time.
He said he pretty much know’s what many model cars are likely to fail with, before it enters the workshop !.
“Differ cars have common failure points at different ages, give me a car and I can go straight to the common failure point, straight away, you get to know after a while”.
He also speaks to other MOT guys in the trade, in order to exchange opinions on any new faults that they may have come across, on a particular model.
Consistency is maintained then.
When the word is out, the word is out.
Bugger !.

 

[macd2401]

I agree to a point but considering the brakes are hardly used because of the regen I think the rear discs are excessively worn for the mileage on the car. The front ones are fine. I had a Honda Accord for 12 years before my ZS and the discs were still good when I sold it.

I would agree, they shouldn't be an issue with such a low mileage, but the reality is, non EVs use their brakes all the time. My old Golf did 130k miles before I needed to change the disks. But I can do my entire commute now, and only need to touch the brakes when I'm reversing out of my drive, and when I'm parking at my work, the rest can be regen. That's going to take a toll just through lack of use. That same Golf has been parked up since January, and the almost brand new disks look hellish now. If I knocked the surface scale off, I'm pretty sure it would be pretty bad underneath, and ours will be no different. It's an EV specific problem, only partly mitigated (by accident?) through MG cruise control using actual braking.

 

[Lovemyev]

I would agree, they shouldn't be an issue with such a low mileage, but the reality is, non EVs use their brakes all the time. My old Golf did 130k miles before I needed to change the disks. But I can do my entire commute now, and only need to touch the brakes when I'm reversing out of my drive, and when I'm parking at my work, the rest can be regen. That's going to take a toll just through lack of use. That same Golf has been parked up since January, and the almost brand new disks look hellish now. If I knocked the surface scale off, I'm pretty sure it would be pretty bad underneath, and ours will be no different. It's an EV specific problem, only partly mitigated (by accident?) through MG cruise control using actual braking.

An unavoidable circumstance of kinetic energy I guess ?.
Brake discs are generally very cheap to replace in the big scheme of things anyway.
The friction pads are likely to be more expensive.
The disc’s could probably be machined at least once to avoid the wastage.
By are likely to get replaced regardless !.

 

[JodyS21]

I had a look the other day on the standard car parts websites I normally use, couldn’t find any discs for the zs ev!

 

[Cocijo]

These are my rears after 10k miles.

 

[Dave53]

Disc is correct for a a flat, thin circular object. Disk is computer speak as in floppy disk.

Strangely they are both flat and round

 

[Dave53]

Just over 4400 miles and getting grinding noise from rear brakes (low speed braking).
So photos of all 4. Clearly, 2 fronts are smoother than rears. How's yours looks like?

Grooves in the discs are more a problem for the pads and not the disc as the pads wear unevenly and breakdown quicker, it is the lack of overall thickness of the disc that would be a safety problem when braking, scoring of the disc and the uneven wear on the pads are the reason for the grinding, but will usually stop after a time not braking when the high points ware down to match the disk, but if you are a person that often drives on an uneven rough track road you will have more issues than cars driven on the tarmac.

 

[macd2401]

I had a look the other day on the standard car parts websites I normally use, couldn’t find any discs for the zs ev!

Having trouble finding ANY parts on most websites. Put the reg or model details in, and suddenly nobody has any of even the simple things like wiper blades

 

[Lovemyev]

Having trouble finding ANY parts on most websites. Put the reg or model details in, and suddenly nobody has any of even the simple things like wiper blades

I have a feeling that with regards to wiper blades, only OEM parts are available !.
I personally like the Bosch Aero Twins blades, but they don’t pick up on a internet search for the ZS EV ???.

 

[Gomev]

Having trouble finding ANY parts on most websites. Put the reg or model details in, and suddenly nobody has any of even the simple things like wiper blades

I suspect most DIY parts, such as wiper blades are the same for the ZS and ZS EV, or is that too simple an idea ?

 

[Lovemyev]

I believe the ZS EV has the wheel hubs from the HS fitted, because as we know the stud pitching / spacing is different.
This was picked up early, when the original space saver sold to customers straight from the ICE ZS, would not fit.
MG then offered the space saver kit from the HS instead.
Are we to assume then, that the brake discs are different from the EV to the ICE ?.
Surely they must be ?.
If they are using the HS disc’s then these should be readily available from a third party by now.
Unless the disc’s are EV fit only, then it will be a dealer supply option only until such a time where the third party people can catch up.
A quick cross check of part numbers would revel the answer to this question.
Just a bit of food for though folks .

 

[jensern58]

Rear brake disc scale / rust, is a direct result of our good old friend "Max Re-gen".
The rear brakes get very little usage due to Re-gen and therefore rust / scale builds up quickly.
I think it is very likely that rear disc's could get replaced prematurely due to scale and rust build up and NOT down to wear / scoring from the brake pads.
In wear terms only, I could see a set of rear pads lasting the life of the car !.

Hello.
I've just had my Ez Ev on the yearly service. S bit puzzled that the rest discs are badly corroded and the pads are worn out. I know the reason, my wife drives it daily and does not "panic brakes" once in a while. Unfortunately the dealer is asking £550 for the replacement and currently there is no aftermarket provider for rear discs here in Norway. Do you know if aftermarket discs are available in England?