In summer, we often hear tire burst and even spontaneous combustion accidents caused by tire overheating, especially the continuous high temperature weather in the South recently. Recently, in the truck Home Forum, a card friend encountered the problem of hot front wheels. “Big beard” put forward some inspection methods for your reference.
First of all, there are two possibilities for the front wheel hub to be hot. One is caused by the hub (shaft head) and the heating of the brake drum.
The hub is at the innermost part of the brake drum, which is the shaft head where the bearing is installed after disassembly. Its high temperature is generally caused by too tight bearing assembly or poor lubrication. Too high temperature will cause the grease inside to melt and flow out, affect the braking effect, and burn the bearing in serious cases. Generally speaking, it is normal that its temperature is within 50 degrees higher than the ambient temperature.
If the shaft is hot, be careful. The bearing inside may be too tight or abnormally worn.
The brake drum is the commonly known “pot” measured by your thermometer. As long as you step on the brake, it will heat up, which is the place where the heat of the whole front wheel is the largest. The temperature of the brake drum is related to the ambient temperature, driving speed, braking times, vehicle weight and road conditions. There are 100-200 degrees when stepping on several brakes, and even the heavy truck can reach more than 300 degrees when going downhill. There is no clear data provision in the current national laws and standards.
If the brake drum is hot, you can jack up the front wheel of the car, turn the tire to see if the rotation is flexible (commonly known as scratch). Then turn the tire and step on the brake to see if the brake returns quickly and completely (commonly known as jam).
If the tire doesn’t rotate flexibly, it means there is interference in the brake drum. If the brake doesn’t return or returns slowly, there is a problem with the brake system. Go to the 4S store for repair.
The outermost place where the tire is installed is the steel ring. It will not heat itself. It is mainly transmitted to it by the heat of the brake drum. If its temperature exceeds 200 degrees, it is very dangerous. The capacity will cause the tire filling nozzle to burn and even burst at high temperature.
If the brake does not return or rubs the drum slightly, it is difficult to test it not only on a gentle slope, but also in the current high-temperature weather, the temperature of the brake drum will rise rapidly. If the high temperature is transmitted to the wheels and tires, it is really dangerous in hot summer.
You should be reminded that as long as you step on the brake, the brake drum of all cars will be hot. The faster and heavier the car is, the higher the heating degree of the brake is. This is the principle of energy exchange.
If abnormal wheel heating is found, it is recommended that you check and eliminate the fault in time according to the above method.
Recommended tools (1) “temperature measuring gun” for temperature test