Why is the right rear wheel brake disc of the car rusty and can't be worn off? What should I do if the right rear wheel brake disc is always rusty?

It is normal for a car's brake disc to rust. For example, humid air and frequent driving in coastal areas can cause the brake disc to rust. In this case, the rust can be worn off as long as the car is running. So what should be done if only the right rear wheel brake disc is always rusty?

Why is the brake disc of the right rear wheel of the car rusted and cannot be worn off?

Generally, even if the brake disc of a car is rusty, the rust will be worn off during driving, and then it will rust again when it encounters an environment that is prone to rust, and the cycle will continue. It is definitely abnormal for the right rear wheel to rust for a long time. You can observe whether the brake disc rusts synchronously with the other three wheels, or whether the rust still exists after using the car. If it still exists, it may mean that the brake pad and brake disc of this wheel are not in sufficient contact, that is, the brake of this wheel is not working.

The possible reasons are that the dust cover of the right rear wheel brake caliper movable pin is damaged, the brake caliper movable pin is lacking oil and rusting and getting stuck, or the brake cylinder piston is rusting and getting stuck, and the brake caliper does not return to its position when braking, resulting in abnormal braking of the right rear wheel and rusting of the brake disc.

What should I do if the right rear wheel brake disc is always rusty?

First, you can drive the car for a while and try to step on the brakes several times. After parking, touch the brake discs of the four wheels. If the temperature of the rusty brake disc is not as high as that of the other three brake discs, or the temperature is obviously higher than that of the other three brake discs, you should check the brake system in time. Drive the vehicle onto the platform and raise it. After releasing the handbrake and footbrake, the wheels should turn smoothly without dragging, and the wheels should not turn when the brakes are applied.

If there is any abnormality in the braking of the right rear wheel, check whether the brake cylinder and brake caliper movable pin of that wheel are working normally, and whether the dust cover of the brake caliper movable pin is damaged, etc. Visually check whether there are cracks or high-temperature redness and rust on the surface of the brake disc, and whether the brake cylinder piston and brake pads are damaged. Replace the brake disc, brake pads, brake cylinder and other components as appropriate.

Why is only one of the four brake discs rusted?

Generally, this situation is probably caused by the rust of the wheel cylinder or the swelling of the wheel cylinder leather ring, which leads to the failure of braking.

If there is a rusty brake disc on the front wheel, the steering will deviate to the other side when you step on the brake during normal driving. This means that the brake is not working on the rusty side.

You can also drive the vehicle at 30km/h on an empty, dry and flat road, apply the emergency brake and see which wheel has no drag marks, indicating that the wheel has a problem.

In addition, if conditions permit, you can jack up the car, have one person step on the brake, and the other turn the wheel. If the rusty wheel can turn, it also proves that this wheel has no brakes.

In the above cases, as long as it proves that the car has no problem with the brakes, just ignore it. This means that the rust on a single brake disc should be caused by water splashing on this wheel.

If it is proven that the rusted wheel does not brake, it is sufficient to prove that there is a problem with the wheel. The main reason is that the piston of the master cylinder is rusted and cannot move, or the leather ring is swollen. In this case, the car may brake when the emergency brake is applied, but not when the brake is applied lightly or lightly, and there is more likely to be brake drag.

Another situation is that the brake fluid is too dirty and the oil pipe of the wheel is clogged.

In any case, if only one brake disc is rusted, in addition to water on one wheel, other problems should be paid enough attention, most of which are caused by problems with the brake fluid or the wheel cylinder. Please go for inspection.