How to Check Truck Tires Before You Roll

To check truck tires before driving, walk to every wheel position and look at the tread, the sidewall, the valve stem, the wheel and the lug nuts, then check the pressure with a gauge. Do it in the same order every time, and do not skip the inside tires of a dual. A tire check should find three things: damage, low pressure and a loose wheel. All three can end a trip on the shoulder, so you want to find them in the yard.

This is one part of the full routine in our truck pre-trip inspection guide. Here we go slowly through tires only.

What a tire check has to find

You are not there to admire the tire. You are looking for a reason the tire might fail in the next few hours.

Damage: cuts, bulges, exposed cord, a tread that is separating, an object stuck in the rubber.
Low pressure: a tire that runs soft heats up, wears fast and can burst.
A wheel that is moving: loose or missing lug nuts, cracks in the wheel, rust trails from a nut.
A bad pair: two tires on a dual that are clearly different in size or wear, or one that carries the load alone because its partner is flat.

If you keep this list in your head, the check has a purpose and does not become a quick glance.

Tread, sidewall and valve stem

Start at one corner of the truck and go around in one direction, so you never forget a wheel.

Tread. Look across the full width of the tire. Check for uneven wear: one edge worn down, or a flat band in the middle. Uneven wear tells you about alignment or pressure problems that the shop should fix. Look for stones or nails caught in the grooves. The minimum tread depth is set by the rules where you work and by your employer. Use their gauge, and do not guess.

Sidewall. Run your eyes, and your hand where it is safe, over the side. You are looking for bulges, cuts, cracks and rubbing marks. A bulge means the inside of the tire is broken. That tire can burst without warning. A cut deep enough to show cord is the same.

Valve stem and cap. The valve stem should be straight, with a cap on it. A missing cap lets dirt in and can cause a slow leak. A stem that is bent or cracked can leak, and on an inside dual it can rub on its neighbour.

Lug nuts, rust streaks and wheel cracks

A wheel does not need a flat tire to cause a crash. A loose wheel can come off.

Look at each lug nut. Are all the nuts present? Are they all seated? Is any nut visibly turned from its mark?
Look for rust streaks running out from the nuts. Bright rust, a shiny trail or dust around a nut means it has been moving. Report it. Do not try to tighten it unless you are trained and it is your job.
Look for cracks around the stud holes and on the wheel rim, and for a wheel that looks bent.
Many fleets paint a small line or put a marker cap on each nut. When the line is broken, the nut has turned. Learn the marker system your employer uses.

Your employer's procedure says who may tighten a lug nut and with what tool. In most fleets, a driver reports and the shop repairs.

Pressure by gauge, not by kick

Kicking or thumping a tire tells you almost nothing. A dual with one flat tire can still sound firm, because its partner carries the load. Use a gauge on the stem, and compare each reading with the pressure your employer gives for that truck and load.

Use a tire gauge that is in good condition and reads clearly.
Check tires cold, before you drive. A hot tire reads higher and gives a false picture.
Compare the two tires of a dual. If one is lower than the other, there is a leak or a problem.
Do not add or release air unless it is part of your job and you know the target pressure.

A tire thumper still helps to compare the two tires of a dual, but treat the sound as a clue, not a measure.

Example: the inside dual nobody looked at

Say a driver, Ana, is leaving a yard at dawn. She walks around her tractor and trailer. At the trailer's rear axle, the outside tires look good. Many drivers would stop there. Ana crouches and looks between the duals with a flashlight.

The inside tire on the left side is much lower than its partner. The sidewall looks wrinkled. She puts a gauge on the stem and the reading is far below the target. The outside tire is carrying more than its share.

Ana does not take the trailer. She writes the defect on the report and tells the yard supervisor. The shop finds a slow leak at the valve stem and replaces the tire. A tire that stayed low for hours on a highway would have heated up. A blowout can throw rubber into traffic and can damage the trailer or the brake lines next to it.

The check took one extra minute. It saved the load, the trailer and possibly someone's car.

When this does not work

In the dark or snow, you can miss a defect. Use a good flashlight and wipe snow or mud off the tire to see the surface.
Wheel covers or mud flaps can hide a nut or a sidewall. Look from a second angle.
A tire that is hot after driving will not give a true cold pressure. Note it, and compare the pair instead.
A small defect may be a no-go or may not be. Your employer's list decides. Our guide on no-go truck defects explains how to think about it.

When in doubt, do not drive on it. Ask the shop.

After the tires: the air system

While you are close to the wheels, you are also close to the brake chambers and the lines. This is a good time to listen for air leaks. In cold weather, water in the air tanks can freeze in the lines, which is why we also explain how to drain air tanks and prevent frozen brake lines.

Learn this in five minutes

The Walk-Around Routine track in CargoSkills teaches a fixed inspection order, with a lesson on tires, wheels and lug nuts, and another on deciding what stops the truck. Each lesson takes about five minutes.