turns out that such a sign as a foot knock on the wheel came to us from the sphere of freight transportation. In the old days this way drivers of heavy goods checked the wheels on their cars. By tapping on the wheel, they carried out tire pressure checks. Previously, wheel manufacturers had installed an additional chamber and exclusively with the help of a knock on wheels it was possible to determine whether the wheel was lowered or not, whether it was necessary to pump.
Then drivers of motor vehicles adopted such habit. To date, manufacturers no longer release camera tires, but many drivers are still tapping wheels with their foot before another trip.
In most cases, people don’t actually wonder whether this is a common sign (superstition) or perhaps there is any meaning in it. Perhaps it’s just a pointless check on the technical condition of motor vehicles.
Is there any point?
I wonder if there really is any point in tapping on the tire with your foot? Is it possible to test the pressure in the wheel this way? At present, motor wheel manufacturers create such tires that normal pressure is maintained in the event of a wheel puncture in the road. Even with a broken wheel, you can travel several tens of kilometers. And if periodically this wheel is pumped, and that is more. The puncture can be detected with the naked eye, because under the weight of the weight of the machine the body will axe and it will be possible to diagnose on which of the wheels puncture and make a replacement.
In the case of passenger vehicles, such diagnostics, in truth, do not make any sense, but on trucks with double wheels, whether the wheel is pulled down or not, $ would be factually unrealistic. It is possible to identify the problem only with the help of the old proven method, such as tapping the foot on the wheel, because the pressure of this type of tires is much greater than that of passenger vehicles. Thus, even the smallest deviation of tire pressure can be easily checked.
Undoubtedly, even the huge plus of this type of wheel inspection is also the fact that when checking the driver needs to completely bypass the vehicle. This will allow further inspection of vehicles and when any deviations are detected, transport the car to the service station and inspect on the lift.
Identification of backlash defects
Some drivers with extensive experience say that by tapping on the wheel can reveal the presence or absence of backlash in hub bearings. During the use of motor transport, bearings have the property of breaking, which leads to a backlash, that is, vibration of the wheel. At high speed, the wheel can come off, leading to a major vehicle accident.
Naturally, if there is a minimal backlash, it will not be possible to check the wheel in this way. Especially in case the motor transport is in a good, flat place. But when the bearing is broken already badly, even if the car is standing on an uneven spot, it will be easy to diagnose that the wheel is “walking”. Hence, it is necessary to make a diagnosis. We draw your attention to the fact that it is impossible to operate vehicles with such a problem. If detected, it is necessary to take the car to the service station with the help of a tow truck and already there to fix this problem.