By James Girards

Dangerous tires are unfortunately commonplace on heavy trucks and are one reason up to one of every six 18-wheelers on the road today are unsafe for those who occupy the highways with them.  For those interested in assuring that tires on a heavy truck meet safety requirements, here is the short version on how to inspect them.  First, gather the proper inspection equipment, to include an accurate air gauge, a tread depth gauge, a blunt probe, a box of valve caps, tire chalk or crayon, a pair of pliers, and a three-eighths inch bulge gauge.  Your task is to identify out-of-service tire conditions, and tire conditions that require attention but do not require the tire to be taken out of service immediately. Tires with operable tire conditions may remain on the vehicle and tires that have out-of-service tire conditions must be removed and repaired before the vehicle is moved.

Proper tire inspection begins with a process or checklist.  So, you will want to begin your inspection by inspecting the front driver's side tire and work toward the rear of the truck and around to the end up at the front passenger side steer tire.

Begins by inspecting the outside sidewall, the tread area and the inside sidewall of each tire.  Look for punctures, snags, exposed cords and missing valve caps.  Also make sure that all tires on each axle are either bias tires only or radial tires only.  Never allow a mix of bias and radial tires on a single axle. Make sure all tires are the correct size. Then, assure the air pressure is correct.  Check for abnormal wear patterns on the tire to alert you to maintenance issues such as alignment that may need attention.  But, if there are any spots more than 4/32-inch on steer tires or 2/32-inch on other axles the tire must be taken out-of-service. Minor cuts on the tread surface and sidewall are okay, but if the cords are exposed the tire must be taken out of service. A bulge on the tire less than 3/8-inch in the sidewall resulting from a repair is an operable condition.  A repaired bulge is sometimes identified by a blue triangular label near the bulge or by a buffed surface on the tire. Use the bulge gauge to determine the height of the bulge. If the bulge is over 3/8-inch and prevents the gauge from touching the sidewalls the tire must be removed from the vehicle. 

Check to make sure that weather checking of the rubber material – those small cracks that appear with age – do not expose any cords.  If so, the tire must be taken out of service.

Sometimes tires with pre-cured retreads will have a small opening at the edge of the tread or the tire with otherwise have a cut on its surface.  Use the blunt probe to assure that any cuts or openings are less than ½-inch.  If greater, the tire must be removed from service.

Tires frequently pick up foreign objects such as nails or screws. So long as the object has not penetrated the tire casing and can be removed without causing a leak the tire can remain in service.  Pouring soapy water over the object to check for air leaks is an easy way to check for leaks.  It is okay to remove a nail or screw so long as the tire casing has not been penetrated and doing so does not result in an air leak. When the tire casing has been punctured or a leak results from manipulating or removing the object the tire must be removed from service.

Whenever you find a tire that should be removed from service, mark it clearly with a crayon or chalk.  

Whenever cords are exposed on the outside of a tire remove the tire from service.  Exposed cords are usually a result of cuts and snags and are generally found in the sidewall area. 

Re-grooved tires are not allowed on steer axles.  However they may be used on drive, trailer and dolly axles.  Sidewall separation, bead cracking, or bumps or bulges are common indications of  a tire that should be removed from service.

A tire is considered flat if the air pressure is 20% lower than the desired pressure or if there's an air leak that can be heard or felt.  Never reinflate a flat tire.  Instead, remove it and have it inspected to determine the source of the leak.

If the tire’s tread depth across two neighboring grooves is less than 2/3-inch on trailer or drive axle tires the tire must be removed from service.

Tires sometimes come into contact with the vehicle.  If the damage is severe or if cords are exposed, the tire must be removed from service and the vehicle repaired so it does not come into contact with any tire.

If the tread depth across two neighboring grooves on steer tires is less than 4/32-inch the tire must be removed.

Tire inspection and maintenance is an important part of every pre-trip inspection and is required to keep everyone on the roadways safe.

For more information contact Girards Law Firm at 888-897-2762 or [email protected]

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