How do you remove rust from brake discs?

Rust on brake discs can cause a number of problems, from reduced braking performance to disc warping or cracking. Thankfully, with the right tools and techniques, removing rust from brake discs can be a straightforward process.

What Causes Rust on Brake Discs?

There are a few key factors that can cause brake discs to rust:

• Exposure to moisture – Brake discs are exposed to water and humidity from the road, car washes, rain, etc. Over time, this moisture causes surface rust.
• Lack of use – When a vehicle sits for an extended time without being driven, the brake discs are prone to rusting.
• Damage to the discs – Chips, cracks, or scratches in the disc surface allow moisture to get inside the metal, promoting rust.
• Corrosive road treatments – In cold climates, road salt and other chemicals used for ice/snow can speed up rusting.

Problems Caused by Rusted Brake Discs

Some of the main problems that can arise from rusty brake discs include:

• Squeaking or grinding noises when braking due to uneven disc surface
• Reduced braking power and performance
• Vibration or juddering sensations through the brake pedal
• Rust expanding and causing disc warping or cracking
• Rusted particles contaminating brake pads and caliper

If left unattended, severely rusted brake discs will need to be fully replaced. That’s why it’s important to deal with rust buildup promptly before it leads to larger issues.

Materials Needed for Rust Removal

Here are the basic tools and supplies you’ll need to tackle rust removal on brake discs:

• Safety gear – Gloves, eye protection, face mask
• Wheel chocks
• Jack and jack stands
• Lug wrench or impact wrench
• Brake disc cleaner or degreaser
• Wire brush, sandpaper, or flap wheel
• Brake lathe (optional)
• Brake grease or anti-seize
• Brake cleaner
• Rags

For more difficult rust removal, you may also need more heavy duty tools like a die grinder, rust removal chemicals, or paint/primer.

Step-by-Step Rust Removal Process

Follow these key steps to thoroughly clean rust off your brake discs:

1. Lift up the vehicle and remove wheels – Use a jack and jack stands to safely lift the vehicle. Remove the front wheels to access the brake discs.
2. Clean discs with degreaser – Spray brake disc degreaser liberally over both sides of the discs and let it soak for 5-10 minutes.
3. Scrub away surface rust – Use a wire brush or sandpaper to scrub off any loose surface rust.
4. Assess if resurfacing is needed – Check if the discs have any deep pitting, gouges, or warping. If so, resurfacing with a brake lathe may be required.
5. Resurface discs if needed – A brake lathe will shave off a thin layer of the disc surface to remove rust pitting and achieve a smooth surface.
6. Clean again with brake cleaner – Use spray brake cleaner to rinse away any remaining debris after wire brushing or resurfacing.
7. Apply brake grease – Rub a thin coat of high temperature brake grease or anti-seize compound on the contact areas of the brake disc and hub to prevent future rust.
8. Reinstall wheels & lower vehicle – Put wheels back on and safely lower vehicle. Check brake operation before driving.

Tips for Rust Removal

• Work in a well ventilated area and wear protective gear when dealing with chemicals or producing metal dust.
• Soak rusted areas with rust remover gel or vinegar to help loosen stubborn rust before scrubbing.
• Avoid using sandpaper or abrasives on the friction surfaces of the brake disc that contact the pads.
• Thoroughly clean the brake caliper and pads of any rust debris when job is complete.
• Consider having badly rusted or warped discs resurfaced or replaced for optimal braking performance.

Cleaning Severely Rusted Brake Discs

For brake discs with severe rust and deep pitting, more intensive cleaning methods may be required:

• Chemical rust removers – Rust remover gels or sprays can penetrate deep rust and dissolve it away after soaking for hours.
• Die grinder – Using a rotary die grinder with a wire wheel or abrasive pad can scrub away stubborn rust.
• Sandblasting – Professional sandblasting services can completely strip all rust off a brake disc surface.
• Disc replacement – In cases of extreme rust pitting that cannot be resurfaced, disc replacement will be required.

Take safety precautions when dealing with chemicals or power tools like die grinders. Avoid damaging the friction surfaces and always re-lubricate discs after cleaning.

Preventing Rust on Brake Discs

Here are some tips to help prevent rust from recurring on your brake discs:

• Drive regularly to avoid having brakes sit idle.
• Wash vehicle often to rinse away road salt and grime.
• Lubricate contact points when changing pads with anti-seize compound.
• Have brake fluid flushed to avoid moisture contamination.
• Store vehicle in a dry garage to limit environmental exposure.
• Address any disc damage like cracks that allow rust to form.
• Consider brake disc coatings that protect from corrosion.

With proper maintenance and driving habits, you can maximize the life of your brake discs and reduce rust buildup over time.

When to Have a Professional Service Your Brakes

While many DIYers can handle basic brake disc rust removal, it’s wise to defer to a professional mechanic for certain brake issues:

• If resurfacing or replacement of rotors is needed
• For servicing the brake caliper, hoses, seals, pistons, etc.
• If brake fluid needs flushing due to contamination
• For realigning or machining rotors that have significant runout or warping
• If you don’t have the proper tools or experience for the job

Brake system repairs require specialized tools and expertise. Have your brakes inspected by a certified mechanic if you have any concerns over their condition or notice any warning signs of problems while driving.

Cost to Remove Rust Professionally

Typical costs for professional brake disc rust removal or repairs include:

Service	Cost Range
Rust removal and disc resurfacing (each)	$50 – $150
Disc replacement (each)	$100 – $300
Brake caliper rebuild	$150 – $400

Additional charges may apply for severe rust requiring extra cleaning time, parts replacement, or other discovered issues. Discuss the full scope of the work with your mechanic beforehand.

Conclusion

Letting brake disc rust go unattended can lead to dangerous brake failure, so being proactive about cleaning and prevention is important. In most cases, DIY rust removal using basic tools and supplies can restore discs to optimal condition. For severely damaged or warped rotors, professional resurfacing or replacement may be the wise solution. With consistent car maintenance and quick action when you notice rust buildup, you can keep your brake discs in safe functioning order.