Wheelbarrow tires can be tricky to inflate, because, unlike automobile tires, most wheelbarrow tires don't have an inner tube. Getting the tire to seal to the tire rim while you're trying to inflate it is difficult. Without the right technique, your wheelbarrow tire will not hold air and leaks in the tire will be plentiful. Using an adjustable strap, such as a luggage strap or a ratcheting cargo strap, and a simple method, you can inflate the wheelbarrow tire.
Place your wheelbarrow upside down on the ground for easy access to the tire. Check the wheelbarrow tire for any holes or abrasions. If the tire has holes in it, repair them with a tire patch kit.
Place an adjustable strap around the circumference of the tire. Tighten the strap until the tire is tight against the wheel rim.
Inflate the tire using an air pump or compressor. Stop the air pump when the wheelbarrow tire has sealed to the rim. Inspect the tire for any air leaks around the rim and for any leaks or holes you didn't detect initially.
Loosen the strap slightly as you fill the tire with air until the wheelbarrow tire can hold the air adequately. Then, remove the strap and fill the tire to the appropriate air pressure indicated by the manufacturer on the side of the tire.