‘Is it normal for rust to form on my car’s brake rotors?’ [Newbie Guide] 

Updated Jul 06, 2021 | Same topic: Beginner's Guide

Corrosion on brake discs can be a scary sight.    

Car owners are a strange bunch. They actively comb every inch of their rides in searching for all sorts of imperfections and flaws, then actually become annoyed when they do find one. Every hairline scratch, every dent, every stain – all these become triggers for the (overly) conscientious motorist.   

Rust on car

Rust is a dangerous thing to ignore where your car's body is concerned

One of the more serious things to look out for in a car is the presence of rust. If found on the body shell, this kind of corrosion is a legitimate cause for alarm, as it signifies that the vehicle’s protective layer has been compromised. Ignore it at your own risk, and the damage can easily spread to the rest of the car. 

Rust on rotor disc

Rust forming on brake discs is fairly common

But what about rust forming on the brake rotors? It’s a common occurrence mainly on vehicles equipped with disc brakes. You might notice patches of rust on the rotor’s surface, especially with a car that’s been parked outdoors or after a rainy drive. It’s quite unsightly to see the rotor’s finish tarnished (not to mention the potential damage it could bring to your wheel), so your first course of action might be to bring the car to the nearest shop. 

Car wheel being washed

Even just washing the car can cause the rotor disc to form rust patches

Except that it doesn’t have to be. Unless there’s a supercar in your garage that’s fitted with carbon-ceramic composite brakes, you likely have a run-of-the-mill passenger car as your daily driver. As it stands, conventional vehicles are equipped with rotors made of cast iron, which is just as good for everyday driving despite being cheaper. Iron is also prone to oxidation or rust, and that’s perfectly normal especially in humid climates like ours.

Car on road

Simply taking the car on a normal drive should be enough to remove the rust

The best way to remove the rust is to simply drive the car, as the friction between the pad and rotor during normal braking will be enough to wipe the corrosion away. But even after a day’s worth of driving, you might find that some rust remains on the vents and edges. Not to worry, because it takes years before it actually affects the rotor disc itself. 

Mechanic fixing brake

You can have it checked by a mechanic if you're still in doubt

What you should watch out for is if the rust has been sitting on the rotor surface for a long time. That could lead to pitting, which compromises the vehicle’s braking performance. You can either have the rotor disc refaced (provided it’s still thick enough), or replaced with a new one altogether.   

If you’re not sure what to do, there’s no harm in having a mechanic take a look at the rotor disc, for your peace of mind.   

Find more tips for beginner car owners at Philkotse.com.

Joseph Paolo Estabillo

Joseph Paolo Estabillo

Author

Joseph has been a member of various car clubs since he got his driver's license in 2004 – old enough to remember riding in taxicabs with analog meters, but his fascination with cars goes way back. After nearly two decades of working in broadcast media, he shifted gears by coming on board as Philkotse’s first Filipino member and staff writer in 2017.

Apart from his role in Philkotse as Content Team Lead, Joseph has written episodes for Drive, which has been airing on CNN Philippines for five seasons running. He has also delivered content for various car dealerships based in the U.S., spanning multiple brands such as Alfa Romeo, Maserati, Jeep, Dodge, among others.

Keeping his hopes high and his revs low, he dreams about owning a Kei car when he retires. Hates slow parkers.

View more
Cash Value