Rusty brake rotors are a common headache for car owners. If left unchecked, it can affect the performance and lifespan of your brake system –- the last thing any driver wants.
What starts with a blemish can quickly escalate to safety issues.
So, how concerned should you be about rust on rotors?
And how can you go about cleaning them?
Read on to explore the causes of rusty rotors, tips on how to care for brake rotors, and more.
This Article Contains:
- Should You Be Concerned About Rusty Brake Rotors?
- What Causes Rust on Rotors?
- How to Remove Rust on Rotors: 3 Effective Methods
- How to Care for Brake Rotors: 6 Tips To Prevent Rust
- 4 FAQs About Rust on Rotors
Should You Be Concerned About Rusty Brake Rotors?
In most cases, brake rotor rust isn’t anything to be concerned about. Light surface rust generally doesn’t affect the braking system, often wiping away with a few presses of the brake pedal while driving.
However, if the rust buildup persists, it can suggest that the rust has penetrated deeper into the disc brake rotors, potentially compromising its structural integrity and braking performance. In this case, the best thing to do is have a trained mechanic perform a brake inspection.
Let’s dive into what causes this rust in the first place.
What Causes Rust on Rotors?
Unless you have a sports car equipped with an expensive braking system, your vehicle would likely have cast iron, steel, or alloy brake rotors. Several factors can contribute to brake rust in these materials:
- Exposure to moisture: This is the main culprit. Rain, snow, ice, and humidity leave moisture on the rotors that, when combined with the iron in the rotors, cause rust.
- Brake dust: Primarily composed of iron particles, brake dust can cause rust to develop on the rotor surface when mixed with moisture and oxygen in the air.
- Road salt: When corrosive road salt comes into contact with brake rotors, it can accelerate the oxidation process, leading to rust.
- Infrequent use: Regularly using your brakes helps keep the rotors clean. The friction between the brake pads and the rotor removes brake rust and debris on the rotor surface. When not used in a while, there’s nothing to remove the rust.
However, not all brake rotors are susceptible to rust. Carbon ceramic brakes, for example, are made from a composite material that’s durable and resistant to rust. Consider upgrading if rust is a recurring issue.
Next, let’s roll up our sleeves and see how to get that rusty brake rotor back in top shape.
How to Remove Rust on Rotors: 3 Effective Methods
There are several methods for removing rust and grime from your brake rotors, each important for brake maintenance.
Method 1: Soap and water
Let’s start with the simplest method: cleaning brake rotors using soap and water.
- Park your car on a level surface: To access the rusty brake rotor, you must jack up the car. Ensure the car is in park and the parking brake is engaged before switching off the engine. Additionally, place tire blocks around the tires to prevent movement.
- Loosen the lug nuts: Loosening stubborn lug nuts can be easier while the tires are on the ground.
- Jack up the car: Securely fit the jack stand and raise the car. Then, remove the lug nuts and each wheel, exposing the iron rotor beneath.
- Apply the solution: Spray the soapy water onto each brake rotor and brake caliper, then gently wipe them down with a clean rag.
- Reattach the wheels: With clean brake rotors, you can reattach each wheel and carefully lower your car back to the ground.
Method 2: White vinegar
A household staple — white vinegar can be an effective car brake cleaning method.
- Wear safety equipment: It’s a good idea to wear gloves and goggles, as white vinegar can irritate the skin and eyes.
- Take apart each brake caliper and brake rotor: With the vehicle raised and the wheels off, remove and disassemble the brake components.
- Fill a large bucket with white vinegar: Ensure there’s enough vinegar to fully submerge the brake calipers and brake rotor.
- Soak the components: Submerge the brake parts for at least an hour. Then remove them and wipe down the brake calipers and disc brake rotors with a clean rag.
- Reinstall: With the brake rotor rust removed, reinstall the brake parts and lower your vehicle, ensuring each component is attached and secured properly.
Method 3: Brake cleaner
If the above two don’t work, get your hands on a brake cleaner for thorough cleaning.
- Use a liberal amount of brake cleaner: With your car jacked up and the wheels removed, thoroughly spray brake cleaner onto the rusty rotor and calipers. Allow it to soak in for a few minutes.
- Scrub the components: Use any wire brush with soft bristles and gently scrub the rotors to help loosen the corrosion. Then, use a stainless steel wire brush to scrub the rotor in a circular motion on the braking surface.
- Wipe off the residue: Use a clean cloth to remove the brake cleaner and light surface rust from the cast iron rotor and calipers.
- Dry the components: Give the components a few minutes to dry completely. Fortunately, the brake cleaner evaporates quickly and leaves no residue.
- Reattach the wheels: Reattach the wheels and lower your car to the ground. Then, tighten the lug nuts and test your clean brake rotors.
Some minor rust may remain on the braking surface, but it’s typically not a major concern. Using your car brakes will continue to clean them. However, if there’s still significant buildup, you may have bad rotors. It’s best to have a professional perform a brake inspection, brake service, and brake rotors repair if necessary.
Now that we’ve removed the rust and grime, let’s check out some handy tips on maintaining your rotors.
How to Care for Brake Rotors: 6 Tips to Prevent Rust
Here are some ways you can slow rusting as part of your brake maintenance:
- Drive your vehicle regularly: The easiest way to minimize the risk of rust buildup is to use your vehicle regularly, even for short distances. The friction from the brake pad against the rotor helps prevent rust from accumulating.
- Park undercover: Parking your car in a garage helps shield the cast iron rotor from moisture, delaying the oxidation process.
- Invest in quality brake pads and rotors: Higher-quality brake pads and rotors are more robust and can withstand more wear and tear, reducing the need for frequent brake pad replacement. Some pads, like ceramic brake pads, are designed to be gentler on the rotor without compromising braking performance. Lower-quality pads could be more abrasive and produce more brake dust.
- Avoid road salt exposure: Wash your vehicle more frequently if the roads are salted in the winter. Road salt is highly corrosive and can expedite oxygenation, leading to bad rotors. High-quality ceramic pads can also help reduce wear and tear from these harsh conditions.
- Use coated rotors: Some rotors ship with a rust-preventative coating applied. If yours doesn’t, you can apply a coating to the non-friction parts of the rotors. Coated rotors can withstand corrosion better.
- Regularly clean your vehicle: Washing your vehicle frequently, including the brake areas, helps remove dirt and residue that trap moisture. Thoroughly dry the brakes after washing by driving a short distance and applying the brakes a few times to ensure safe braking in the future.
Having covered how to care for brake rotors, let’s tackle some common questions about rust on rotors.
4 FAQS About Rust on Rotors
Explore the answers to some commonly asked questions about rusty brake components.
1. How Much Does it Cost to Fix Rusty Rotors?
A new rotor from an auto repair store can cost between $30 and $70, with higher quality and coated rotors costing a little more. Labor for rotor and pads replacement should be $150 to $200 per axle.
A professional mechanic can charge between $200 and $500 for rotor and brake pad repair.
2. Should I Replace My Brake Discs if They Rust?
Rusty brake discs are a common issue. Surface-level rust can usually be cleared with regular use or by manually cleaning them.
However, rust that has penetrated deeper into the brake disc can compromise the function of your brake system. This leads to safety issues, including increased stopping distance. If rust remains on the rotor after cleaning, it’s best to consult with auto repair services for a potential brake job.
3. Can Rusty Rotors Cause Grinding?
Yes, a rusty rotor can lead to a grinding noise when pressing the brake pedal, especially if the car has been idle for some time. Usually, the sound clears up after using the brakes a few times, as the brake pads rub away the rust.
That said, worn rotors with more severe rust will lead to a constant grinding sound. This happens when the rust creates an uneven surface, and the pads can’t make smooth contact with the rotors. If the grinding noise persists, it’s best to book a brake repair and have your worn rotors replaced.
Note that if your brakes make a squeaking or squealing sound, it’s likely an issue with the brake pads. You’ll want to have that kind of brake noise checked out by a professional.
4. Do all Rotors Rust?
Most cars manufactured these days have a disc brake on the front wheels and either disc brakes or drum brakes on the rear wheels.
Note: Drum brakes don’t use rotors. Instead, they have a drum with brake shoes on the inside. When braking, the shoes press outwards against the drum’s inner surface.
A disc brake features a thin, flat disc (or rotor) with brake pads that apply pressure against the brake disc, slowing the car.
There are a few types of brake rotors, and some are more susceptible to rusting than others.
- Standard smooth brake rotors: Smooth brake rotors are the most common with disc brakes and are prone to developing surface rust, especially when the vehicle isn’t used frequently or is exposed to humid environments.
- Slotted rotors: Slots or grooves cut into the surface allow slotted brake rotors to dispel excess heat and dust from under the brake pads. This enhances braking performance and helps prevent a warped rotor by ensuring even heat distribution. Additionally, slotted brake rotors stay cleaner and drier.
- Drilled rotors: Also referred to as cross-drilled brake rotors, these high-quality have holes drilled into them to help dissipate heat buildup. Like slotted rotors, these holes help minimize surface rust. However, cross-drilled brake rotors can develop rust in the holes.
- Drilled and slotted rotors: Combining both designs, these high-performance rotors combine the benefits of slotted and drilled types. This helps prevent a warped rotor, but it has rust concerns similar to slotted and drilled rotors.
In all cases, the best defense against a rusted rotor is regularly using your vehicle and proper maintenance.
Cure Rusty Rotors with AutoNation Mobile Service
Brake components are not ones you want to neglect. If rust has compromised your brake rotors, have a mechanic for a brake repair ASAP.
And if you’d rather avoid driving with a rusted rotor, you’re in luck — AutoNation Mobile Service is here to help.
We’re a mobile auto repair and maintenance solution offering upfront pricing and a 12-month| 12,000-mile warranty on all repairs.
Contact us, and our expert technicians will perform a brake service and install a new rotor and new brakes right from your driveway.