Flat Tire Repair: What Can Be Safely Repaired?
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A flat needs a safe way to reach help before it needs a repair decision. These steps cover roadside choices and what to ask a tire technician. A leak that stops after an outside string plug still needs an internal inspection; a plug alone or a patch alone is not a proper permanent repair.
Do not drive on a flat tire or attempt an outside-in string-plug repair. Use roadside assistance if the location is unsafe or no usable spare is available. A proper repair needs the tire removed from its wheel and inspected by a technician. Never put any part of your body under or beside a car supported only by a jack.
What you'll need
- Phone and roadside-assistance details
- Owner's manual (spare or factory mobility-kit instructions)
- Usable spare, gauge, jack, and lug wrench — only for a safe spare change
- Tire technician for removal, inspection, and any repair
The steps
Tap through one step at a time — built for one-handed use at the roadside — or switch to all 7 steps to read ahead or print.
Step 1 of 7: Stop somewhere safe
Step 1: Stop somewhere safe
Slow gradually and stop on firm, level ground away from traffic. Set the parking brake and hazards. If the shoulder is narrow or the ground is soft, call roadside assistance rather than work beside passing traffic.
Step 2: Look without removing the object
Note any visible nail, cut, bulge, or damage and tell the technician whether the tire was driven flat. Leave a nail or screw in place; pulling it out can release the remaining air. A visual check cannot rule out internal damage.
Step 3: Use a spare or arrange roadside help
If the location is safe and you have a usable spare and the correct tools, follow the tire-changing guide and your owner's manual. Check the spare with a gauge before driving. Otherwise arrange assistance or a tow. A factory mobility kit is only a temporary measure: follow its instructions and limits.
Never work under or beside a car supported only by a jack. If you cannot change the wheel safely, wait for roadside assistance.
Step 4: Have the tire removed and inspected
A tire technician must remove the tire from the wheel to assess the inner liner and other hidden damage before deciding whether repair is possible. Tell them about earlier repairs and any sealant or mobility kit used.
Step 5: Check whether repair is allowed
Only qualifying tread punctures up to 1/4 inch (6mm) may be considered. Shoulder or sidewall injuries, overlapping repairs, hidden damage, and the tire maker's restrictions can rule out repair. There is no universal two-repair allowance; the tire manufacturer's policy governs.
Step 6: Ask for both a stem and an inner-liner patch
A proper puncture repair fills the injury with a rubber stem or plug and seals the inner liner with a patch. A combination patch-and-plug unit can do both. A patch alone or a plug alone is not enough; an outside-in repair without inspection is not acceptable.
Step 7: Follow the replacement and pressure advice
If the tire cannot be repaired, ask which matching replacements your vehicle needs; AWD tread-depth requirements can affect more than one tire. Have the shop set the correct pressure. If using a compact spare to reach the shop, follow its speed and distance limits.
Frequently asked questions
Sources
Where the figures on this page come from. Your owner's manual still wins for your specific vehicle.
- Tire Repair BasicsU.S. Tire Manufacturers Association (USTMA). Cited for: A technician must remove and inspect the tire; a proper puncture repair fills the injury with a stem or plug and seals the inner liner with a patch. Outside-in and on-the-wheel repairs are unacceptable, and repair limits depend on the tire manufacturer's policy. Checked .