🌡️ The wheel is heated: all possible causes and troubleshooting methods

Immediately “from the threshold” there is a strict rule - if there is a suspicion that the wheel is heating up on the car, you should not touch it with your hands. Burns will be provided. It is quite possible to understand that the wheels are hot in safer ways. Among them: a characteristic burnt smell; swollen or blackened paint on the discs; blue brake discs; bad rolling; the car "leads" to the side; vibration during braking; crackling wheels after stopping. You can finally make sure of inadequate overheating using a pyrometer, if available.

Why do car wheels get hot?

All the reasons why the wheels heat up are conditionally divided into three groups:

1. Natural heating - any factors that lead to an increase in the temperature of the hubs and discs, but are not any kind of breakdown.
2. Brake problems - in absolutely all cases, the root cause of wheel heating is parasitic friction.
3. Problems with the hubs - the friction force also heats up here, but the sources of problems are not related to the brake system.

These groups are too generalized and uninformative, and therefore not everyone will be able to solve the problem. But in each of these general groups there are several specific reasons that are needed:

• know;
• be able to identify;
• eliminate if possible.

In this vein, all the information below is presented.

Natural heating of the wheels

As already mentioned in the definition, in this case, the wheels can heat up despite the fact that the car is fully functional. That is, you don't have to do anything. You may need to slightly change your driving style or be more careful to fix the problem. The latter, by the way, does not only apply to beginners, and below is why.

Scorching sun

In direct sunlight, wheel rims can easily get hot enough to cause painful burns when touched with bare hands. However, such heating is not critical in itself. No matter how scorching the sun is, because of it, the paint on the disks will not be able to swell and blacken. Moreover, bluish spots on the brakes will not appear.

However, this factor may well exacerbate the impact of other causes, which will be discussed later. That is, if there is any malfunction due to which the wheel heats up, in the heat the problem will manifest itself much earlier and more noticeably.

It is easy to understand that the disks overheated precisely because of the sun's rays. To do this, it is enough to compare the temperature of the parts after driving in the dark. If in this mode the heating is moderate or absent at all, the sun is to blame, and there is no point in looking for other reasons. Everything is okay.

Frequent braking

The need for intensive work with the brake pedal arises, as a rule, in urban driving. A similar situation happens on the road. If the brakes are used too often, they naturally heat up and simply do not have time to cool down. On the track, by the way, it is enough to slow down once at high speed to overheat the wheels.

How to know that hot wheels are for this reason? Again elementary. If you once notice overheating, immediately think about the mode in which the machine was operated before. If with intensive use of the brake system - this is the reason. To verify this, it is enough to compare the condition of the wheels after a normal, calm and measured ride.

Low movement speed

The brake system of the car is designed for the fact that excess heat after friction of the pads on the discs will be given off to the environment. Movement contributes to this process, as the brakes are blown by an oncoming air flow. Part of the heat energy is also transferred to the rims. If the speed is low, or the car does not stand still after intensive braking, it is not surprising that the wheels have warmed up.

The note. On some machines, the standard braking system is absolutely not designed for aggressive driving. Brake discs are small, not ventilated. The pads are also small. As a result, such brakes overheat very quickly, even if you are not reckless, but simply moving in the city among heavy traffic. There are two options here - either try to drive slower so that the brakes have less work, or replace the assembly parts with more powerful ones.

Driving with the handbrake not released

Many may self-confidently think that this problem threatens only novice motorists. However, as practice shows, this is not always the case. Even the most experienced drivers with many years of experience manage to periodically forget about the handbrake. Especially if this node on the machine works “at half strength”. That is, the pads are pressed against the discs, but the wheels are not completely blocked. As a result, the car seems to be driving, and the rear wheels are heated.

Life experience. It is not necessary to be a beginner in order to forget about the handbrake one day in a new car. The car is unfamiliar. Perhaps you just bought it and you are overwhelmed with emotions. It also happens that the steering wheel is transferred to the driver who rides something else, which means that his attention can go past the lever or handbrake button.

This should probably be mentioned separately. Anyway. Cases should not be discounted when the handbrake did not turn off after disengagement, or did it incompletely. That is, the car was removed from the handbrake, and the pads to the drums (or disks) got stuck, froze, and so on, or did not completely move away from them. The result - the rear wheels are heated. To identify this reason, it is enough to hang each wheel in turn on a jack, rotate it and inspect the details of the brakes. As a rule, it can be seen with the naked eye that for some reason the pads did not move away from the working surface of the discs. It remains only to establish the cause of the breakdown and eliminate it.

Brake problems

After eliminating factors that are not related to malfunctions, you can proceed to the analysis of breakdowns. First of all, it’s worth starting with the brakes, as they are the cause of heating of the wheels in 70% of cases. In short, the problems of the braking system that are interesting in this situation include the following:

• consequences of driving on a handbrake;
• jamming of the piston of the brake cylinder;
• airing the system;
• excessive wear or damage to the brake discs;
• unsuccessful repair.

Let's consider each of the points in a little more detail.

Consequences of driving on the handbrake

After accidentally driving with the handbrake applied, the wheels can get warm for one of two reasons:

1. Pads stuck.
2. Discs warped.

Stick pads due to critical overheating. In some cases, this also leads to thermal expansion of adjacent parts of the brake system, due to which they jam. You can identify sticky pads yourself. The problem is usually visible to the naked eye. As for troubleshooting, it all depends on your skills, desires and the availability of a tool.

It is perhaps worth talking about the deformation of the brake discs separately, since this is not the only possible defect.

Stuck brake piston

Brake cylinders with pistons are on each wheel. It is they who set the pads in motion when you press the pedal, creating high pressure in the lines of the system. When the pistons are wedged or wedged tightly in the cylinders, the pads cannot return to their original position after braking. They continue to rub against the disks constantly, as a result of which the wheel hub is heated, and then the disk.

Piston jamming in cylinders is most often caused by contamination. There are anthers on these parts, the damage of which is guaranteed to end in similar problems. Natural wear of the brake cylinders cannot be ruled out either. If the problem is detected in a timely manner, and the resource of the parts has not yet been exhausted, then the breakdown is eliminated by banal cleaning and lubrication. You should also take care of the tightness of the brake cylinders so that dust, water and dirt do not get into them.

There is air in the braking system

There should be no air in a working hydraulic brake system. If it appears there, the node does not work completely. That is, the brake pads may well be incompletely retracted from the discs or drums, as a result of which the wheels will heat up. Along with this problem, failures of the brake pedal can be observed, about which there is a separate article on the site. Be sure to read to broaden your horizons.

It is impossible to visually detect air in the brake system. This can be done only by indirect signs, many of which are described in the material on pedal failures. If these appear, and are accompanied by heating of the hubs, bleed the system. If pumping does not give a positive result, then, perhaps, the wheels are heated for another reason.

Critical brake disc wear

Serviceable brake discs should be:

For the presence of deformations, the brake discs are inspected from the end. To do this, you need to hang the car on a jack and remove the heating wheel. Along the way, the part is inspected for damage to the working surfaces. These are the ones that the brake pads rub against. They should not be blue, deep scratches and concentric furrows. If the disk is crooked or scratched, this is the reason why the wheel is heating up.

Replacement of brake pads

Quite often, after replacing the pads, the wheel disks heat up, which, in general, is not a breakdown in most cases. After a few hundred kilometers, the parts will run in, and they will no longer heat up. Quite different conclusions should be drawn if the new pads are of poor quality or are not suitable for this car. It is possible that non-original spare parts were bought to save money. In such cases, it is better to immediately replace the pads with normal ones, since everything can end not only with heating wheels.

Hub problems

After eliminating the natural causes of overheating of the wheels and problems with the brake system, it remains only to check the hubs. Absolutely all possible problems of this node are diagnosed on their own in the garage.

Here is a short list of possible hub problems that cause the wheels to heat up:

• jamming of guide calipers;
• critical wear of wheel bearings;
• lack of lubrication in wheel bearings;
• the tightening torque was not observed when repairing the hub.

Literally in a nutshell on each problem.

Stuck caliper guides

Most often, caliper guides wedged due to clogging or corrosion. Natural wear of parts is also possible. After hitting a good hole, deformations of the guides occur. To diagnose this breakdown, the wheel of interest is hung on a jack, removed, after which the assembly is inspected. If no signs of wear are visible, then, most likely, it will be possible to eliminate the breakdown by washing and lubricating the parts. In case of wear, replace.

Learn more about jammed brakes.

Wheel bearing worn out

When the wheel bearings wear out, the axis of rotation of the wheels is disturbed, due to which the parts are subjected to parasitic friction and heat. Later, the breakdown manifests itself in the instability of the car, and ends, as a rule, with terrible wobbling from side to side or we jam the wheels tightly. Wheel bearings cannot be repaired. Complete replacement only. Preferably on both sides on the same axis.

To check the wear of the wheel bearing, hang the wheel on a jack and, without removing it, sway along the axis of the car, holding the top and bottom of the tire. If there is noticeable play, the bearing is either worn or not tight enough.

Wheel bearing ran out of grease

Most often, the grease in wheel bearings quickly burns out due to the fact that the hub overheats. And she begins to do this because wear has occurred or the grease has burned out. An almost vicious circle, which, when one of the problems occurs, closes in a few kilometers. As a rule, this problem is not detected in a timely manner, therefore, lack of lubrication leads to bearing wear. Another replacement.

Wheel bearing over tightened during repair

This often happens when a car is repaired by oneself or at a service station by inexperienced craftsmen. For each car, the manufacturer prescribes its own tightening torque for the hubs, which must be observed. Overloaded bearings quickly overheat (wheels with them), the grease burns out or evaporates, and everything ends with a wedge or critical wear.

Cheat sheet

Brief summary

From the foregoing, it follows that there are at least a dozen reasons why the wheels of a car are heated. It is always worth starting the search with natural sources of heating. Next, the brake system is diagnosed, since it is it that most often causes overheating of the hubs and rims. Last of all (or in the presence of indirect signs), the hubs are checked - caliper guides, bearings, and so on.

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