Every driver at least once in his life faced a situation when the car on the move behaved strangely, pulled to the side or the steering wheel became heavier than usual. Often, behind these symptoms lies a banal but dangerous problem. depressurization. This is a condition in which the tightness of the bus-disk system is disturbed, which leads to a gradual or sharp decrease in air pressure.
Why isn’t it just the nails on the road? The fact is that the modern tubeless tire is a complex design, where tightness is ensured by the tight fit of the rubber sides to the shelves of the disk. Any violation of this integrity, whether it is a microcrack in the cord or oxidation of the metal, leads to a loss of pressure.
Ignore this process can not, as riding on a flat wheel destroys the sidewall of the tire and can lead to an accident at high speed. In this article, we will examine all aspects of the problem: from the physiology of the process to methods of self-finding holes and professional repair.
⚠️ Warning: If you feel a sharp impact or a strong roll of the car when driving, immediately turn on the alarm and smoothly reduce speed, avoiding sharp braking. Stopping on the flat wheel should be done as soon as possible, but without emergency manoeuvres.
What is depressurization and how it affects movement
Depressurization is the physical process of leaking compressed gas from a closed volume. In the context of a car, this means that the tire pressure drops below the normal specified by the manufacturer. Normal pressure is usually between 2.0 and 2.5 atmospheres, and even a slight deviation in the 0.2-0.3 atmosphere changes the dynamics of the machine.
When the pressure drops, the area of contact between the tire and the road increases, but is not evenly distributed. side-slips tubeless begin to turn, which leads to overheating of the rubber and destruction of the inner cord. It's not just discomfort, it's a direct path to breaking the wheel at speed.
In addition, depressurization affects fuel consumption and tread wear. An under-performed wheel has greater rolling resistance, the engine uses more energy, and the rubber wears off at the edges faster than in the center. Long driving with low pressure can disable the suspension.
The main causes of tire pressure loss
Finding the cause of depressurization is always a process of exclusion. The driver needs to know the basic scenarios to understand what he is facing. The causes are divided into mechanical damage, disc problems and natural wear and tear of materials.
The most obvious reason is a puncture. A sharp object (nail, screw, glass shard) penetrates through the tread. However, there are less noticeable options, for example, a “hernia” on the sidewall or stratification of rubber due to old age.
Separately, it is worth highlighting the problems with the disk. Aluminum discs are prone to oxidation at the edge where the side of the tire adjoins. The formed layer of oxides does not allow the rubber to press tightly, creating microgaps for air output. Steel discs can be deformed from impacts on curbs, violating the geometry of the fit.
- 🔩 Mechanical puncture of the tread or sidewall by a foreign object.
- 🌡️ Natural diffusion of air through rubber pores (normal loss of up to 0.1 atm per month).
- 🛑 Deformation of the wheel after falling into a hole or hitting a curb.
- 🌫️ Oxidation of the disk seat or metal corrosion at the contact point with the rubber.
Effects of Temperature on Pressure
When the air temperature drops every 10 degrees Celsius, the tire pressure drops by about 0.1-0.2 of the atmosphere. In winter, this can simulate depressurization, although the tire is physically intact.
Symptoms: How to know if the wheel is running
Modern cars are often equipped with a system. TPMS (Tire Pressure Monitoring System), which signals a pressure drop with a light bulb on the dashboard. However, on older cars or with a slow leak, the driver may not notice the problem for a long time until it becomes critical.
The first sign is often a change in steering behavior. The car starts to pull towards the damaged wheel. If you let go of the steering wheel on a straight road, the car is taken aside. Vibration on the steering wheel or body may also appear, especially at high speeds.
Visual inspection is the most reliable method. If you notice that one wheel looks more flattened from the bottom than the others, then depressurization has already occurred. Sometimes the leak is so slow that it is not visible visually, so regular checks with a pressure gauge are mandatory.
⚠️ Please do not blindly trust the TPMS system. Sensors can get bad, and in very slow leakage, the system will work when the pressure drops to a critical level.
The main symptom of depressurization is the car's withdrawal to the side when moving in a straight line and the change in the sound of the rolling (the hum becomes louder and lower).
Diagnosis: search for the place of leakage with their own hands
Before you go to the service, you can try to find the leak site yourself. This will help to understand whether a tourniquet repair is possible or a more serious intervention will be required. The easiest and most affordable method is the use of soap solution.
To do this, dilute liquid soap or dishwashing agent in water. Pour the foam over the entire surface of the tire, including the tread, sidewalls and, most importantly, the connection of the tire to the disc. Watch for the appearance of bubbles.
If bubbles appear on the tread, it means that there is a nail or puncture. If the bubbles go in a circle at the junction with the disk - the problem is in the oxidation or curved disk. If the bubbles come from under the nipple (gold) - it may be contaminated or damaged.
Leak search algorithm:1. Remove the cap from the nipple.
2. Spray the nipple with soapy solution.
3. If bubbles go, the problem is in the spool.
4. Handle the entire perimeter of the tire and tread.
5. Find the place of active bubbling (bubbling).
☑️ What you need for home diagnostics
Repair methods: harnesses, patches and sealants
The choice of repair method depends on the nature of the damage and the place of puncture. Not all damage can be repaired on site, some require tire dismantling and vulcanization in a workshop.
For through punctures in the tread area (tread) tourniquets are often used. These are sticky rubber cords that are inserted into the puncture hole with a special stitch. This is a temporary solution that allows you to get to the service, but does not guarantee long-term tightness.
A more reliable method is the installation of a “fungus” or a combined patch from the inside of the wheel. To do this, the tire must be removed from the disk, clean the puncture site, degrease and glue the patch with a vulcanizing composition. This ensures full tightness and allows the wheel to be operated further.
| Type of damage | Repair method | Reliability | Cost |
|---|---|---|---|
| Tread puncture (nail) | Tourniquet/Fungus | Tall. | Low. |
| Sidewall damage | Not repairable. | — | Replacement of the tyre |
| Facilities puncture (on board) | Fungus (truncated) | Medium | Medium |
| Disc oxidation | Cleaning and sealant | Tall. | Low. |
There are also aerosol sealants (“canisters”) that are poured through a nipple. They work on the principle of filling the volume with foam, which tightens the puncture. This is an emergency tool, after which you often have to throw out pressure sensors and wash the disk from the inside for a long time.
Use only specialized tubeless tire sealants compatible with TPMS sensors if they are installed on your vehicle. Aggressive chemistry can eat into the rubber seal of the sensor.
Prevention and care of wheels
To avoid sudden depressurization at the wrong time, you must follow simple rules of operation. Regular visual inspection of wheel arches for stuck stones or nails helps prevent serious problems.
It is important to monitor the shelf life of the tires. Rubber eventually “blowns”, loses elasticity and begins to crack. Even if the tread is deep, an old tire (over 5-6 years old) can begin to poison the air through microcracks in the structure.
When seasonally replacing tires, ask the masters to lubricate the side of the tire with a special composition. This prevents rubber from drying out at the point of contact with the disc and facilitates future dismantling while maintaining tightness.
- 🗓️ Check the pressure with a pressure gauge at least once a month and before long trips.
- 🧼 Wash the disks at each wash to notice damage or corrosion in time.
- 🚗 Avoid hitting curbs and driving holes at high speed.
- 📅 Change the tires every 5-6 years of operation, regardless of the residual height of the tread.
Can I drive a flat tire before the tire fitting?
You can drive only as a last resort and at a very short distance (up to 1-2 km) and with a minimum speed (up to 20 km / h). Long driving on a flat tubeless tire destroys its sidewalls, after which recovery will become impossible.
Why does the wheel run down, even though there are no holes?
Often the reason lies in the loose adhesion of the tire to the disk (mud, oxides, dents) or in a faulty nipel (gold). Also, air can escape through the pores of old rubber or cracks at the welding site of the disk.
Is it dangerous to use a tourniquet to repair the wheel?
The rod is considered a temporary solution. It can dry out over time or shift when the tire is heated. For permanent operation, it is recommended to use an internal patch of the "fungal" type with vulcanization.
How often should you pump your wheels in winter?
In winter, the temperature changes are great. When leaving a warm garage in the cold -20 ° C, the pressure can drop by 0.3-0.4 atm. It is recommended to check and pump the wheels in winter every 2-3 weeks.
What to do if you punctured a wheel on the track?
Turn on the emergency, smoothly drive to the side of the road. Set an emergency stop sign. If you have a spare, change the wheel. If not, call a tow truck or mobile tire. Do not try to ride on a fully flat tire.