Corroded (rear) discs

[Rip Van]

Has anybody cleaned their rear discs manually, after being told they need replaced due to corrosion?

 

[Rolfe]

I didn't do it myself, but my local garage did it for me. My dealer tried to upsell me nearly £2,000 worth of unnecessary work at my 2-year service including replacing discs and pads. I told them no way and took the car to the local chap who was scheduled to switch the tyres for the summer ones a few days later anyway.

He looked at the brakes and said they needed a bit of a clean-off, that's all, and suggested stripping them down and doing that while he had the wheels off anyway. They're absolutely fine. Dealers are sharks.

 

[salty]

Trouble is Rolfe. There's a lot of Prey out there, for them.

 

[Rolfe]

I have an update. I left Caliban at the local garage to have his winter (all-seasons) tyres put back on. I also asked them to check the brakes, also the minor undertray damage the dealer had said was dangerous and needed new undertrays. Verdict, all is fine, undertray damage (some small holes) wasn't any worse and the brakes don't need any further attention at the moment.

My dealer is a shark. Not that they're my dealer any more.

 

[JonnyG]

Best bet I’ve found is to use them weekly by braking hard from a high speed, maybe twice even, on the lowest regeneration mode. Almost an emergency stop pressure is needed as long as it’s safe of course.

I have a nice quiet dual carriageway for doing mine

 

[siteguru]

If you knock it into neutral before stepping on the brakes then you'll get no regen effect at all - the whole stopping force will be from the physical brakes.

(Knock it back into D while you're still moving, at about 10 mph or so, else you'll have to come to a full stop to be able to get back into D. Just my anecdotal experience - no other evidence for this).

 

[Anon70]

Reversing into parking spots can also help to clean off the discs as there is no regen in reverse

Reverse Spinning Parallel Park | Gifrific

A car reverses quickly and then spins in between two other cars for a perfect parallel park.

gifrific.com

 

[Kenp1]

I have an update. I left Caliban at the local garage to have his winter (all-seasons) tyres put back on. I also asked them to check the brakes, also the minor undertray damage the dealer had said was dangerous and needed new undertrays. Verdict, all is fine, undertray damage (some small holes) wasn't any worse and the brakes don't need any further attention at the moment.

My dealer is a shark. Not that they're my dealer any more.

All seasons are a great idea, I had them on my Sportage for four years, also fitted them on the MG4 a few months back, it saves the hassle of having to swap between summer and winter.

 

[T1 Terry]

Let my wife drive the car for a few kms, not only will the discs be cleaned, any oxidised rubber that may have built will be removed as you slide sideways into the first corner and she remembers it is not the Gen 2 Prius with all the body stiffening and handling upgrades ..... but I'm still impressed the MG isn't in the shrubbery and the rubber part is still facing down ...... she often remarks how quiet it is .... the reply that the tyres screaming for mercy can still be heard, generally doesn't go down well at all Part of the reason we will probably never own an XPower

T1 Terry

All seasons are a great idea, I had them on my Sportage for four years, also fitted them on the MG4 a few months back, it saves the hassle of having to swap between summer and winter.

Do the winter tyres come with those screw in studs? The wife would love a set of those, she could literally tear up the road with a set of those

T1 Terry

 

[Rolfe]

Do the winter tyres come with those screw in studs? The wife would love a set of those, she could literally tear up the road with a set of those

T1 Terry

No. That's snow tyres. You practically never see these around here these days. Maybe in the Alps.

All seasons are a great idea, I had them on my Sportage for four years, also fitted them on the MG4 a few months back, it saves the hassle of having to swap between summer and winter.

That's what I was going to do, but I still had a the set of Continental summer tyres the car came in, and then I acquired two more summer tyres during the Hardknott Pass fiasco, so I decided to run the Goodyears as winter tyres until the summer tyres wear out.

 

[Rip Van]

No. That's snow tyres. You practically never see these around here these days. Maybe in the Alps.

Norway. You can hear them rattling on city roads.

 

[Rolfe]

I can imagine.

 

[JonnyG]

Reversing into parking spots can also help to clean off the discs as there is no regen in reverse

Reverse Spinning Parallel Park | Gifrific

A car reverses quickly and then spins in between two other cars for a perfect parallel park.

gifrific.com

Haha …. I tried that when Vauxhall used to do their track day events with their (then) range of cars VXR’s etc.

Used to be a lot of fun … slalem time trials, track experience with an instructor and the above parallel parking between plastic blow up cars of course !! Plus a lap as a passenger with a BTCC driver. Shame they stopped doing them as they were great value and a group from our office always went and had a fun half day.

 

[Panther]

Haha …. I tried that when Vauxhall used to do their track day events with their (then) range of cars VXR’s etc.

I remember when the Vauxhall owners put on a discounted 'skid' training day, a lot of fun I actually learned a lot of things regards ABS and cadence breaking.

 

[Sparky2]

The corroded brake disc replacement is a well known and lucrative wheeze by all main dealer service departments. Before they removed asbestos from brake pads and got China to make the discs out of shit steel, I use to get at least 80k miles out of a set of front discs on big ICE BMWs and Audis. My tip is to take the car up to around 50-60 mph on a straight, dry road, check your mirrors and brake hard a few times before taking the car for a service, especially for an MOT test. Better still if you can put something heavy in the boot like bags of sand.to help clean the rear discs

 

[Scotsman]

Take it down the motorway at 70 mph in reverse and apply the foot brake that will clean the brakes and maybe 3 penalty points just joking . If you are handy with some sand paper you could remove the wheels and clean the disks with the sand paper, unfortunately it's not just an MG problem it's all EV or hybrid problems because the motors are doing most of the braking, so I would advise taking the car on a back road driving at 50 mph plus and applying the foot brake with heavy pressure should clean the brakes of rust , and do that every so often and you will have nice shiny brakes .

 

[CarlThom]

The corroded brake disc replacement is a well known and lucrative wheeze by all main dealer service departments. Before they removed asbestos from brake pads and got China to make the discs out of shit steel, I use to get at least 80k miles out of a set of front discs on big ICE BMWs and Audis. My tip is to take the car up to around 50-60 mph on a straight, dry road, check your mirrors and brake hard a few times before taking the car for a service, especially for an MOT test. Better still if you can put something heavy in the boot like bags of sand.to help clean the rear discs

Brake corrosion is caused by using high levels kers as the brakes don't get any use. Keep kers to 1 and use brakes as in an ice car, saves mega money on new discs etc

 

[MG Clive]

I would advise taking the car on a back road driving at 50 mph plus and applying the foot brake with heavy pressure should clean the brakes of rust , and do that every so often and you will have nice shiny brakes .

I do this regularly when I'm on my own, never with the Mrs in the car, she'd play hell with me.

 

[siteguru]

Brake corrosion is caused by using high levels kers as the brakes don't get any use. Keep kers to 1 and use brakes as in an ice car, saves mega money on new discs etc

The problem is that regardless of the regen setting, pressing the brake pedal increases the regen %age first before applying the physical brakes. So the regen setting is largely irrelevant. It's having a situation where there in no regen that is needed for fully using the physical brakes.

 

[Scotsman]

If it's an EV press the accelerator and brake at the same time whilst driving and brakes will be applied not regen just keep accelerating . Or do an emergency stop your brakes will activate. Not regen .