Rusty brake discs

[IDC]

I use a lot of regen braking, but still the brakes get applied and yet this is now permanent on all four brake discs.

Anyone else finding this?

 

[Mikel14]

I use a lot of regen braking, but still the brakes get applied and yet this is now permanent on all four brake discs.

Anyone else finding this?

Yes, rust on disc's worse on the rear also rear callipers sticking on especially after rain.

 

[DBedford]

Reduce region setting, find a safe less populated stretch of road, and do some heavy braking.

 

[MG Clive]

It looks quite bad for a 4 month old car, mine still look shiny and new, do you have particularly bad roads up there?

 

[Alb]

What does that surface feel like?

 

[IDC]

DBedford, I have tried regen 1 and heavy braking and it did not make a difference.

MGClive, what do you mean by bad roads and how would that cause rust? I noticed it after the car sat for 5 days unused whilst we were away. There has been no gritting of the roads yet.

Alb, the surface feels smooth.

 

[MG Clive]

MGClive, what do you mean by bad roads and how would that cause rust? I noticed it after the car sat for 5 days unused whilst we were away. There has been no gritting of the roads yet.

I was meaning grit/gravel/salt etc getting trapped and causing the grooving in the discs, I was looking more at the grooves than the rust.

 

[Aitch1]

I use a lot of regen braking, but still the brakes get applied and yet this is now permanent on all four brake discs.

Anyone else finding this?

I have also noticed the heavy rust on the disks, more so on the rears. I put this difference down to the braking system favours the front brakes when slowing down to a stop. I'm not sure whether or not to be alarmed over the excess rust. Does anyone know of any issues caused by rusty disks? Other cars I've owned all showed rust when not used for a couple of days, but the rust disappeared once the car was driven any distance. I'm also wondering if the regen system actually applies the brakes, or does it rely on the engine to provide that drag?

 

[IDC]

I was meaning grit/gravel/salt etc getting trapped and causing the grooving in the discs, I was looking more at the grooves than the rust.

It looks like there are grooves, but the disc is smooth. It is like the metal has stained with a rusty colour.

OK, so I washed the car and used the Turtle Wax Redline wheel cleaner, which goes on like a gel and the discs, which had been going more silver, have gone back to the colour in the photo. It is a cleaner that turns brake dust red, so I wonder if that is staining the discs.

 

[SteveG511711]

Hello IDC, I believe that this is normal. In the past I have owned expensive cars and the discs look similar even on vehicles costing a lot more money. Cast iron discs will obviously discolour but so do many stainless steel discs; perfectly normal. Someone in the forum suggests some heavy braking to 'polish' the discs but what is the point? They will soon discolour again. I deal with stainless steel and I'm not sure if anyone makes discs of marine grade metal? Possibly not. If they were available they would be more expensive to buy of course. But, goodness, they would look good! Looking at the picture of the disc, the grooves seem to be a tad 'heavy'? Sand or fine grit on the roads where you are? Anyway, nothing to worry about other than they don't look great. My car is the same and only 5 months old; the discs look old and tired (they are not of course). I suppose we will have to live with 'Chinese' stainless steel or whatever metal the discs are made of. Regards, SteveG.

 

[mgpooter]

Yes mine are the same and worse after rain as we are used to with discs on all cars. Taking it easy and on the standard regen braking 2 level the brakes rarely get used only on the odd emergency which I haven't even had yet. I wonder if continually switching to the lowest regen braking and then actually using the brakes to slow and stop will keep those discs clean. I have previously had (ICE) cars where the rear callipers have seized as its very likely only the fronts ever got used during normal light braking. I can see these rear callipers seizing in future. Might be worth double checking the brakes really do get bled every other year as always recommended.

 

[Cooperman]

What the eye doesn't see!!!
Don't forget that if the car was fitted with steel wheels or more enclosed alloys you may never have noticed the discs!!!

 

[mgpooter]

Agreed but seized callipers always used to be a failed MOT. I wonder how they will test these brakes, if they will work in neutral and if the 'hand'/parking/rear brake can be tested OK?

 

[MG Clive]

Agreed but seized callipers always used to be a failed MOT. I wonder how they will test these brakes, if they will work in neutral and if the 'hand'/parking/rear brake can be tested OK?

MOT testers will have been testing cars with EPBs for 15 years or more, so they should know how to test them by now.

 

[mgpooter]

That's good news I have never trusted my life with switches before. It does seem we are stuck with these cheaper things now. One thing the first MG3s had was a trusty handbrake.
Still, everything is working so no complaints.

 

[IDC]

I now have shiny brake discs and am sure the issue was the wheel cleaner I was using. It is Turtlewax redline wheel cleaner and boy does it turn everything red, more so that any other of the cleaners that turn brake dust deposits red. It really stains the brake disc itself.

​