Should I be concerned about rust on my brake discs?

After leaving your car out in the elements for a while, you may notice that your brake discs have rust on them, especially after a rainstorm or after you wash your car. Rust is a big red flag in a lot of cases. When you consider that the brake system is one of the most important systems in your car, you could be forgiven for being concerned if you notice a bit of red on the discs.

It's a good habit to perform these visual checks first before getting out of the car and driving. This allows you to determine whether or not you need to perform general vehicle maintenance or get a professional to have a look during a car service in Reading. But don't worry, a little surface rust isn't a bad thing. Worry if the rust becomes too deep or does not disappear after a short drive.

Why are my brake discs rusting?

This comes down to the brake discs material. Unless you have a high-end vehicle with carbon-ceramic brakes, your discs are most likely made of cast iron, which rusts easily. When exposed to water or moisture, iron oxidises easily, and rust forms on the surface of the discs.

Having said that, regardless of ride height, most cars on the road, whether SUVs or sedans, will experience discs rusting. This phenomenon affects even crossovers. Because most common cars use cast-iron discs, it's only a matter of when it rains, from your average Toyota Yaris to your more premium Mercedes Benz.

When does too much rust become too much?

In most cases, if you leave your car parked outside overnight in the rain, starting it and stopping once will be enough to remove the surface rust from your discs. If your car has a lot of miles on it, you may notice that the rust on the top portion or vents of your discs is much thicker and darker than the rust on the surface that contacts the pad. Even so, this level of rust is normal and will not impair the disc's performance. If in doubt when next searching for full car service near me, let your car mechanic know of your concerns.

However, do not leave the rust on.

Because oxidation and rust eat away at the metal, it is critical to drive your car on a regular basis and use the brakes to remove the accumulated oxidation on the surface of your discs. Surface rust becomes a problem when it penetrates deeper into the disc and begins to eat away at its structural integrity. When looking for car service near me, get a trained technician to have a look at the discs.

How can I repair rusted brake discs?

Either fix is not always required, but if your discs are beyond repair, you may need to take your car to a garage where they will grind away the rusted surface of the disc, leaving a nice clean and bare area for your callipers to clamp down and your brake pads to make good contact.

If the damage is too severe, or your car mechanic determines that your disc is beyond repair, a new set of discs will solve your problem.

How do you remove rust from brake discs?

To remove rust from the brake discs, use brake cleaner. Place a tray down to catch any spills, then spray the discs with brake cleaner. Allow the discs to dry before wiping it down with a clean rag (no oil on the rag). Apply more brake cleaner and work the surface with steel wool or a wire brush if any rust remains.

Is it a MOT failure if your brake discs are rusted?

If the initial light corrosion is not addressed, it can worsen and lead to surface pitting. Because Pitting used to be a reason, discs should only fail the test if they've become severely weakened.

How do you know when it's time to replace your brake discs?

A grinding sound when braking. If you hear a grinding sound when braking, it could mean that your brake pads or discs need to be replaced. Brake pads have a metal wear indicator that makes a noise when it comes into contact with the brake disc. When your pads are worn to this extent, you will almost certainly need to replace the discs as well.

When should you replace your disc brakes?

Brake pads should be replaced every 50,000 miles in most cases. Some must be replaced after 25,000 miles, while others can last for 70,000 – it all depends on the factors listed above. Consult the owner's manual for a more precise figure for your vehicle's specific requirements.