- turn each wheel first. Carefully remove stones and other objects from the tread with a screwdriver. If glass or a nail is found in the tire, air may be escaping in this place;
- pay attention to possible damage to the tread - breaks, cuts, cracks. If the rubber is damaged, moisture can get inside the tire. From the outside it is impossible to determine whether corrosion of the metal cord has begun. For greater safety, entrust tire inspection to a specialist. The same should be done with increased wear;
Pic. 342. Measurement by a tester on a tire of the depth of its tread
- the tread depth over the entire surface of the tire must be at least 1.6 mm. Some tire brands are equipped with a special wear indicator in several places, the installation points of which are marked with letters «twi» (tread wear indicator) on the sidewall of the tire. For safety reasons, replace tires at a wear depth of 2 mm. Vehicle handling deteriorates as tire wear increases, especially on wet roads. To measure the tread depth, special testers are used, which are applied to the tire, as shown in fig. 342. By pushing in the measuring pin, on the scale of the tester, you can determine the value (in mm);
- check the uniformity of tire wear;
- inspect the sidewalls of the tires. «Hernias» and protrusions indicate tire damage.
Types of tire wear
Tire wear looks like this:
- worn outer edge (front wheels). Too fast cornering. Rearrange the tires on the disks on the other side or rearrange the wheels;
- the outer edges are worn more than the middle of the tread. The tires have been under-inflated for a long time;
- transverse wear strips. Indicate incorrect wheel angle settings, especially if the tire is worn on only one wheel;
- heavy wear of the middle of the tread. Occurs with frequent driving at maximum speed. Under the action of the lifting force, the tires bulge and the middle wears out more. This effect is especially pronounced on the rear wheels;
- uniform wear marks. The shock absorber may be defective;
- uneven wear (in several places). Wheel imbalance. Balance wheels;
- heavy wear in one place. May occur when braking with a wheel lock.