Flat Tire Repair & Assessment

Recognize a flat and assess the stopped situation

A flat tire does not always fail with a loud bang. In some cases, the first sign is a sudden drop in pressure or a tire that looks soft, flattened, or collapsed against the road. The vehicle may begin to pull to one side, feel less responsive when steering, or produce unusual vibration, thumping, or noise. A tire-pressure warning light can also indicate a leak, although it may illuminate before the tire looks visibly low. Treat any change in handling as a reason to reduce speed and assess the situation promptly.

If you suspect a flat while driving, stay calm and keep a firm grip on the steering wheel. Ease off the accelerator, slow gradually, and avoid abrupt braking or sharp turns, which can make the vehicle harder to control. Signal and move toward a stable place away from moving traffic, such as a wide shoulder, parking area, or side street. Choose level ground when possible, and avoid stopping near a blind curve, narrow shoulder, or soft surface. Once parked, secure the vehicle and use hazard lights if conditions require them.

Inspect the tire from a safe position, looking across the tread and around the visible sidewall. Check for a nail, screw, shard of glass, or other object embedded in the tread, as well as cuts, bulges, or areas where the rubber appears torn or distorted. Do not pull out an embedded object: removing it can cause air to escape more quickly and may complicate repair. If accessible, check whether the tire’s bead—the edge that seals against the wheel—appears separated or displaced. Do not put yourself in traffic or beneath an unsupported vehicle to complete an inspection.

Some damage is not suitable for a roadside do-it-yourself fix. A visibly damaged sidewall, a blowout, a separated bead, or extensive tearing calls for professional help. The same is true if traffic, weather, poor visibility, or a narrow shoulder makes inspection unsafe. In those circumstances, remain in a safe location and contact roadside assistance or a tire service provider rather than attempting to continue driving.

Understand temporary options and professional repair

The right response to a flat tire depends on the damage, the tools available, and the conditions where the vehicle has stopped. Installing a spare is often the most practical way to continue a journey, provided the vehicle carries one and it is in usable condition. A compact temporary spare may have speed and distance limits, so follow its label and the vehicle manual. A full-size spare may allow more flexibility, but it should still be checked for correct pressure and compatibility.

Use a temporary sealant or inflator kit only when the vehicle and product instructions permit it for the particular tire damage and conditions. Follow all stated limits and arrange professional inspection or replacement promptly. A kit does not establish that the tire is repairable. A plug alone is not the complete repair described in USTMA’s tire-repair guidance, which calls for removing the tire for inspection and both filling the puncture and sealing the inner liner. Do not treat an external plug as a substitute for that assessment and repair.

For a repairable puncture, a tire professional can remove the tire and assess it from the inside. A proper internal repair typically combines a plug and patch, after checking that the tire has not suffered additional damage. Repairs are generally limited to small punctures in the tread area. Damage to the shoulder or sidewall, a large hole, or evidence that the tire was driven while severely underinflated usually means the tire must be replaced. Do not assume a puncture is repairable without inspection.

Before starting, consult the vehicle manufacturer’s instructions and check any spare-tire limits and repair-kit directions. Useful supplies include a spare tire, jack, lug wrench, wheel chocks, pressure gauge, gloves, and flashlight. Keep the vehicle manual accessible, and carry a reflective warning device if recommended. Work only on firm, level ground, secure the vehicle as instructed, and never position yourself beneath a vehicle supported only by a jack. If conditions are unsafe or the damage is uncertain, call roadside assistance instead of attempting a roadside repair.

Vehicle-specific spare-wheel precautions

Before changing a flat tire, move the vehicle as far from traffic as possible and choose firm, level ground. Avoid soft shoulders, slopes, and locations where passing vehicles could put you at risk. Turn on the hazard lights, shift into park (or into gear for a manual transmission), and apply the parking brake. Place wheel chocks against a wheel that will remain on the ground. If the vehicle is in an unsafe position, call roadside assistance rather than attempting the repair.

Check the owner’s manual for the correct jack location and the vehicle maker’s instructions. Remove the spare, jack, and lug wrench. While the flat tire is still on the ground, loosen each lug nut slightly by turning it counterclockwise; do not remove them yet. Position the jack only at the designated lifting point, then raise the vehicle until the flat tire clears the ground. Never put any part of your body under a vehicle supported only by a jack.

Remove the loosened lug nuts and keep them together where they cannot roll away. Pull the wheel straight off. Align the spare with the wheel studs and slide it into place. Hand-tighten the lug nuts until they hold the wheel snugly against the hub. Lower the vehicle carefully until the spare touches the ground and cannot rotate freely, then remove the jack according to the manual.

Tighten the lug nuts with the wrench in a crisscross pattern, alternating between opposite nuts so the wheel seats evenly. Use a torque wrench to reach the specified torque whenever available; do not guess or overtighten. Fully lower the vehicle, stow the equipment, and check that the spare is secure. Follow the vehicle maker’s directions for rechecking lug tightness, including any specified distance or timing.

A compact spare is temporary and may have strict speed and distance limits. Check its label and the owner’s manual, drive cautiously, and arrange for repair or replacement of the flat tire promptly. Do not exceed the spare’s stated limits, even if the vehicle feels normal.

Checks after repair and future tire care

Once the tire has been repaired or replaced, verify its pressure with a reliable gauge. Check the tire when it is cold—before driving, or after the vehicle has been parked for several hours. Use the pressure specified on the driver-side door placard or in the owner’s manual. Do not use the maximum pressure molded into the tire sidewall as the target; that figure is a limit, not the vehicle’s recommended operating pressure. Inflate or adjust the tire as needed, and check the other tires as well.

Monitor the repaired tire for continued air loss. Recheck its pressure after the repair and over the following days, following any guidance from the repair shop. A pressure that drops repeatedly may indicate an incomplete repair, a damaged valve, a leak at the rim, or another puncture. Have a tire professional assess the problem rather than repeatedly adding air and assuming the tire is safe. Record the repair date, location, and any pressure readings to help identify recurring issues.

Some repairs are temporary and require prompt inspection or replacement. Follow the repair provider’s instructions about speed, distance, and duration, and arrange a professional assessment as soon as practical. If the damage is on the sidewall or shoulder, the tire is visibly bulging or badly torn, or it will not hold pressure, do not drive on it. Driving on a flat or severely underinflated tire can cause further damage and reduce control. In these situations, use roadside assistance or arrange a tow; this is also safer if you cannot change the tire in a secure location.

Regular checks can reduce the chance of another roadside problem. Check tire pressure monthly and before long trips, inspect tread and sidewalls for cuts, bulges, embedded objects, or uneven wear, and rotate tires on the schedule in the owner’s manual. Keep a usable spare, jack, lug wrench, and any required locking-wheel-nut key in the vehicle, and confirm that the spare is properly inflated. If slow leaks recur or the damage’s location or severity is uncertain, ask a tire professional to inspect the tire and document the recommended repair or replacement.