Why your car has iron on its wheels (and why it's not good for them)

What's in brake dust? Why can't it just go away?

2w ago

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You've probably had it on your knuckles. You've certainly had it on your trousers too. Brake dust gets everywhere – it feels as if it's impossible to do the most menial of car DIY tasks without inadvertently getting what looks like soot all over yourself.

But what is brake dust, why does it exist and how the bloomin' heck can you make sure it never troubles you again?

Why is brake dust a thing?

Quite simply, brake dust is the result of your car's brake pads wearing away the surface of your brake discs. It's usually a mixture of iron particles that have been ground off your brake discs, and sometimes metal elements from your car's brake pads (which are usually made up of steel fibres), as well as carbon residue. In short, it's a mix of all the physical elements that scrape and burn away from your brake discs as you use them.

Can I avoid it building up in the first place?

Sure, if you take a very bold new approach to driving where you don't use your brakes. But we wouldn't really recommend that. You can buy non-metallic brake pads, but they're usually horrendously expensive and rarely available for most cars. There's also the fact that cars with carbon ceramic brakes don't produce anywhere near as much brake dust as regular brake systems… so if you were looking for another excuse to buy a GT3 RS, there you go. Have that one on us.

Want to avoid brake dust? Get a Veyron, complete with carbon-ceramic brakes. You can thank us later

Want to avoid brake dust? Get a Veyron, complete with carbon-ceramic brakes. You can thank us later

Is brake dust dangerous?

According to a 2020 study by King's College London, 'metallic abrasion dust' (ie. brake dust) can cause inflammation in your lungs and reduce your immunity, and it can contribute to pneumonia and bronchitis. So yes, it's pretty nasty stuff and you want to avoid breathing it in – although getting it on your hands probably isn't going to do you any harm so long as you wash it off.

It's also not great for your wheels – if you leave brake dust on a wheel for too long it can start to corrode them, eating through the protective clear coat. It can also etch into the metal of your wheels, and it's doubly bad if you just rub it off. Doing this is a bit like rubbing a fine grade of sandpaper across your rim.

How can I clean it off?

Be gone, annoying dust

Be gone, annoying dust

You're best off using a proper iron remover, such as Gtechniq's W6 Iron & General Fallout Remover. It's designed to decontaminate your wheels and paintwork without damaging any of your car's clear coat. Once you're happy your wheels are clean, you can then apply a protective coating to help reduce how much brake dust sticks to your wheels in future – something like Gtechniq's C5 Wheel Armour – which essentially gives your wheel's a protective ceramic coat to stop brake dust nibbling away at your rims. So to speak.

So there you have it – a whistle-stop guide to brake dust and how to avoid it.

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Comments (6)

  • When I lived in London I had a cough that would last about three months out of every year. Since I left it’s gone. And I also learned that the amount of brake and tire dust is above safe levels in every borough. I used to think that replacing all those vehicles with EVs wouldn’t make much of a difference, but I was forgetting about regenerative braking.

      16 days ago
    • When the 15 mph new speed limit is finally introduced into London Town, gonna miss the stink of brake dust in the nose and the black boggies.

        14 days ago
  • Brake dust is residue from your brake pads….. pay more for your brake pads and you will find you will have less dust around your wheels.

      16 days ago
  • How to permanently get rid of brake dust?

    don't use your brakes, just crash into something that isn't too expensive

      14 days ago
    • Dump an old Rover 95 at the end of each street and crash into it, will stop you.

        14 days ago
  • Just get a Taycan with carbon ceramic brakes. While normal driving you rarely brake and if you use them sometimes they produce not a lot of brake dust.

      16 days ago