We want to start off by saying: We’re sorry.
It’s very rare that someone looks up information online on how to plug a tire if they aren’t also currently standing on the side of the road (be careful!) next to a car with a flat tire, or if they haven’t just found their car sitting on a tire that looks suspiciously low on air.
So we’re guessing you’re currently in one of those situations, and again, sorry about that.
Flat tires are a frustrating thing to have to deal with, and can also be quite frightening if that tire goes flat while driving, especially at high speeds. If you’ve already switched out the flat tire for the spare, you’re probably wondering if the tire can be salvaged instead of purchasing another brand new one (or more, as most tire stores recommend replacing two or four tires at a time).
We do have some good news - it’s possible to plug your tire using a plug kit, and safely extend its life (while also lowering your immediate costs significantly). Here’s how:
If the tire is leaking due to a puncture in the sidewall, you can go ahead and stop reading here - it’s time for a new tire, full stop. Sidewall punctures cannot be safely plugged or patched.
If you look in the tire’s tread and you find a screw or a nail or other item still stuck in the puncture, however, a tire plug kit is an option. Before you remove the offending item, remember to make a mark on the tire with chalk or a piece of tape so you don’t lose the hole later.
If you can’t find the puncture, fill the tire with enough air so that it’s got some pressure in it, and either listen for where the air is hissing out, or spray the tire with some lightly soapy water and look for where bubbles start to develop - there’s your leak.
Your plug kit will come with a reaming tool which is used to bore a hole in the tire to a size appropriate for the plug kit. In the spot where the puncture was made, ream the tire until you have a nice, clean round hole for the plug. If the puncture is too small to get the reaming tool into, you may have to pre-drill a slightly smaller hole with a power drill.
Also in the plug kit will be a plug tool with an eyelet, and the plugs themselves, which resemble sticky wires. Load a plug into the eyelet and prep it with the tire cement included in the kit. The eyelet plug tool will allow you to insert the plug into the hole and remove the tool while leaving the plug in place.
It’s going to take a bit of elbow grease to get the plug down into the hole, which is to be expected if you want the plug to make an airtight seal. Once the plug is all the way into the hole and the plug tool is out, the ends of the plug will still be sitting above the surface of the tire. That’s fine, too - you can just cut it off the excess with a razor blade (making sure not to cause another puncture, of course).
Let the plug cure/harden for the recommended amount of time, refill with some air, doublecheck that the plug is fully seated using the soapy-water technique to be sure. If everything looks good, fill the tire to the recommended PSI, then go ahead and get that tire back on your car. You’re good to go.
Absolutely. Tire plugs have been known to keep a tire rolling for thousands of miles, and the plug itself doesn’t affect the tire’s balance or the overall traction of the tire.
That said, take a flat tire as an opportunity to really look at all your tires - check the tread and know what kind of lifespan your tires have. If they’re nearly at the end of the road, it might be a good time to recognize the plug is a short-term fix and be glad that flat reminded you it was time to swap out your car’s shoes.
Most kits are the same: The reamer/borer, the plug tool, the tire plugs and tire cement. Pretty simple stuff, and as such most kits will run under $10, though there are some larger kits with more extensive tire repair maintenance tools that run between $25-$50. If you’re measuring “cost” in terms of downtime, a tire plug kit usually takes far less time than arranging a trip to the tire store, so it’s preferable on both counts.
Both methods get the tire to a place where it can hold the approved amount of air pressure, but they do so in different ways. Tire plugs are small pieces of material that go into the hole and adhere, while a patch goes over the leak - usually from the inside.
Plug kits are the easier solution overall, because patch kits require the tire to be taken off the rim and repaired from the inside. If you don’t have the tools to do that, you’re making a trip to the tire store with the patch kit regardless. It’ll still save you a few bucks compared to a brand new tire, but the time difference is significant.
Visual learners will love that Hagerty has produced a video detailing the process of plugging a tire at our YouTube channel. The even easier option is to become a Hagerty Drive Club member. Why? Because membership includes $100 towards emergency services like lockouts, battery jumps, and tire changes - or roadside plugging.