If you drive the car for a while and the friction surface (where the pads meet the rotor) looks corroded and pocked instead of smooth and shiny, the rotor will need to be turned or replaced. Thanks to its toughness, durability, and heat-handling properties, steel has long been the material of choice for building automobile braking system components.
The latter is largely responsible for creating the friction your vehicle uses to stop whenever you press on the brake pedal. In most cases, rust is an eyesore that slowly but surely eats away at the integrity and appearance of your vehicle.
And, because your brakes are near the road, largely unprotected, and go through numerous heating and cooling cycles on every drive, they’re even more likely to suffer once corrosion sets in. For instance: brake rotor surfaces may become covered in a thin film of rust if the vehicle is parked outside during a rainstorm or heavy snowfall.
Moisture coats the surface of the steel brake rotor, leaving a very thin layer of rust behind. Since it’s a thin layer and exists only at the surface of the steel rotor, it will disappear after a few moments of driving as the brake pads rub it off.
Over time, this rust can weaken the backing plate considerably, causing brake pad friction material to chip, crack, or even separate entirely, which can result in a drastic loss of stopping power and control. Once rust finds its way beneath the glue that holds the friction material to the backing plate, a painted brake pad becomes compromised.
Heavy rusting can be caused by the chemicals used to melt ice during winter as well as exposure to salt water. The brake pads are considered wear items and are only covered for one year or 12,000 miles, whichever comes first.
He has over 40 years of experience in the automotive business and is an ASE certified master technician. I've noticed that the brake discs (I think that's what they're called) on my new Infinite G37 are covered in rust.
Each time you park your car, the freshly minted surface of each rotor is exposed to the elements. As you have discovered, the fresh unprotected cast iron will begin rusting almost immediately.
Every editorial product is independently selected, though we may be compensated or receive an affiliate commission if you buy something through our links. The popularity of alloy wheels puts brake rotors on full display.
You can clean up rusted rotors in several ways, depending upon how bad it is. The most important safety tip you must observe: No lubricant (such as WD-40) or permanent coating should ever be applied to the braking surface of the rotor.
You will likely start to see some rust forming on the rotors if the vehicle sits in one place for a few days. Take the vehicle out for a spin that includes some stop-and-go driving, then check the rotors.
Find a deserted street or an empty parking lot. Start the vehicle in motion, getting up to 10 mph or so, then brake hard.
The rotor can be cleaned with the pads and caliper in place, but it may be easier to do if you remove them. Lift the caliper assembly free of the rotor and secure it in a position in the wheel well where it can hang without causing damage to the brake line.
Use a box-end wrench to loosen and remove the bolts securing the caliper bracket (which holds the pads). As long as the brakes are apart, we recommend that you take a moment to inspect the pads for glazing on the surface (a crystalline appearance).
Any loss of integrity found on these boots exposes the moving parts to dirt and corrosion that can cause them to seize. Put down a tray to catch any runoff, then spray the rotor with brake cleaner.
If some rust remains, apply more brake cleaner and work the surface with steel wool or a wire brush. As mentioned before, the caliper assembly may be left in place, but you will have to turn the rotor to access the area covered by the pads.
If brake cleaner and some elbow grease doesn't do the trick, remove the rotors (if the caliper assembly and bracket are removed, this may be as simple as using an impact screwdriver to loosen an anchor screw (not present on all vehicles), and then sliding the rotor off the lugs. If needed, scrub with steel wool or a wire brush, being careful not to score the surface of the rotor.
Once the rotors are clean, work backward to reassemble the brakes and remount the wheel. A large C-clamp may be required to retract the piston in the caliper assembly so it will fit over the brake pads.
Because removing rust from rotors is a cosmetic exercise (normal use of the vehicle keeps it in check), painting the hub will improve the appearance and prevent the non-braking surface of the rotors from becoming unsightly. Before mounting a new set of rotors, apply brake caliper paint to the center section of each.
Source: Kim is preparing to divorce Kanye West The rotors are bare metal and acquire a film of surface rust very quickly if they get wet.
It happens frequently on cars that are stored outside or, in my case, if I inadvertently direct the hose onto the rotors while washing the car the rust film appears overnight. Then there's a launching noise on the first brake application and thereafter all is back to normal.
Disc brake rotors are bare metal. It's common for them to accumulate rust if the car sits outdoors for a few weeks or more.