Corroded (rear) discs

[PeteC]

I tried this on my MG4, and it definitely DOESN't happen this way.
Keeping a steady pressure on the accelerator with right foot, and a +ve power meter, any pressure on the brake pedal with left foot, instantly turns the power meter to -ve numbers!

That's different to my MG4 where I'm pretty sure the power meter remains positive when I left foot brake while pressing the accelerator. It's how I cleaned up my discs pre MoT. I'll double check next time I'm out in it.

 

[decrep]

That's different to my MG4 where I'm pretty sure the power meter remains positive when I left foot brake while pressing the accelerator. It's how I cleaned up my discs pre MoT. I'll double check next time I'm out in it.

If you are correct, that means we can't assume any behaviour is consistent over the range.

 

[T1 Terry]

If you are correct, that means we can't assume any behaviour is consistent over the range.

Our poverty pack certainly cuts the throttle as soon as the brake pedal is touched, that is how I ended up with the MG running over the stops on the trailer .... learnt, albeit a tad late, use the park brake and throttle for manoeuvring ..... not sure if applying the park brake while planting the throttle would work, as I've mentioned before ..... I have my own disc cleaner

T1 Terry

 

[ReintjeWA]

Our poverty pack certainly cuts the throttle as soon as the brake pedal is touched, that is how I ended up with the MG running over the stops on the trailer .... learnt, albeit a tad late, use the park brake and throttle for manoeuvring ..... not sure if applying the park brake while planting the throttle would work, as I've mentioned before ..... I have my own disc cleaner

T1 Terry

Pulling on the parking brake overrides the accelerator, I've tried it to answer someone else's question about it a while ago;

Post in thread 'Using the electronic parking brake or the P button whilst driving at speed??'

Aug 16, 2025

Here is the dashcam footage, I did 60 kph and 80 kph apparently. During the second one you can hear some clicking/thumping noises which is the ABS activating. And as you can see the car takes off again as soon as the EPB button is released.

MG4 EPB activation at speed

MG4 EPB activation at speed

www.veed.io

• ReintjeWA

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As far as the topic is concerned I have a long stretch of quite road (the one in the above video) where I switch to Neutral and brake hard to clean the discs every now and then. I always reverse out of my parking spot at home, so that uses the friction brakes as well, but probably not enough to clear the discs.

 

[Muffler]

Hard/heavy braking at full charge is also effective for cleaning the disks as regen is disabled at 100%

 

[LenEV2016]

Hard/heavy breaking at full charge is also effective for cleaning the disks as regen is disabled at 100%

One of the issues is People have not always been able to fully clean their discs using this method due to issues with their pads applying uneven pressure and only cleaning part of the disc