When your car has been parked outside for some time, chances are that you’ll see some streaks of rust form on your brake discs, especially after a bout of heavy rain.
That’s normal given how much rain falls in our local climate on any given day.
The high local humidity also plays a factor in causing rust on brake discs.
Depending on who you ask, some say that the rust is the brake degrading, while others say it’s nothing to worry about.
Who is right?
Brake rust: What is it?
Unless you own an exotic car with carbon-ceramic or silicon carbide brakes, the brake rotors on your car are probably made out of cast iron.
On the road, they typically offer excellent braking qualities, usable and powerful enough for your daily driving needs.
However, being constructed out of cast iron, brake rust forms easily on the surface of iron discs when they’re wet.
It can form literally overnight, especially if you park your car outside where it faces the rain and sun constantly.
Unless you live in a very dry or arid region of the world, brake rust is inevitable in a wet and humid climate.
Is it something to worry about?
Thankfully, it is nothing that you need to worry yourself over.
When you next drive your car, applying the brakes should instantly wipe the rust off the rotors (and pads).
You don’t even have to deliberately apply the brakes: just putting the brakes on while normal driving is enough to wipe the rust away.
Even if you do that, rust might still be present in and around the vents and on the outer edge of the rotor.
That still doesn’t present a problem, and it will take a very long time before it actually affects the disc.
It only becomes a real problem if you allow it to sit on the brake disc for a long time.
In that instance, the rust eats away at the brake rotor and causes surface pitting.
That means the surface of your brake disc is not smooth, which could impact braking performance.
If you really feel that your brake disc has been affected by brake rust, one way to solve that problem is to get them machined.
It means to smooth down the disc’s surface, provided there is still enough thickness left on it.
How can I prevent it?
Just make sure that you park your car indoors whenever you can.
Not only does it protect your brakes, it prevents your paint from prematurely wearing out.
Having said all that, brake rust cannot be prevented, but it’s definitely not something you should worry about either.