Proper tire repair is an important part of tire life cycle management. A puncture can ruin your day, so you need to pay attention to proper tire repair.
Tires are among the most essential components of your vehicle. Unfortunately, a flat tire, a slow leak, or a puncture can and has happened to most of us. Whether you are driving to the store, going home, or traveling across the country, you can hit a nail, screw, or some sort of debris that has fallen onto the road. It doesn’t matter how careful and attentive you are, you are most likely to end up with a flat tire at some point and may require it to be repaired. This step-by-step guide to tire repair will show you everything that you need to know.
Proper tire repair involves taking the tire off of the car and removing it from the wheel. It should be thoroughly inspected for all damages and the proper way to repair the tire is by patching it from the inside while filling the puncture hole with rubber cement.
A bad tire or a puncture can put everyone who rides in the vehicle as well as other road users at risk. This is why this comprehensive article is important, especially if you find yourself in a scenario where you need tire repair. In researching and writing this article, we derived information from TIA, USTMA as well as existing industry-approved guidelines. The procedures shown here are also consistent with those used by tire makers such as Michelin and Goodyear. Again, the information represents a consensus of tire manufacturers and industry experts.
Importance of Proper Tire Repair
In addition to ensuring the safety of those riding inside your vehicle, proper tire repair is essential in prolonging the life of the tire casing by installing a permanent worry-free repair. In other words, the tire’s usable life can be extended if the tires are repaired properly.
Proper tire repair can also save you the money that you’d otherwise have spent on buying new tires. More importantly, it can help in reducing waste, thereby making the environment more conducive.
And that’s not all; improper tire repair is illegal and this means that you have to ensure that the tire repair is done properly as stipulated by the government through the Department of Transportation (DOT). This is to make sure that the tire repairs are done properly to avoid sudden tire failure on the road (more on the government regulations on tire repair later).
You have to keep in mind that improper tire repair can lead to unsafe conditions not just on the road but also to the technician installing the tire on the wheel and the vehicle. Improper tire repair can also lead to the constant loss of air pressure, which can lead to premature tire failure. More importantly, your tire will have a shorter lifespan if it’s improperly repaired and this can lead to frequent repairs and replacements.
Tire Repair Guidelines
The DOT has set some guidelines to regulate how tire repairs and maintenance are done. Other guidelines are also set by the U.S. Tire Manufacturers Association (USTMA, formerly known as the Rubbers Manufacturers Association) and the Tire Industry Association (TIA). These guidelines are as follows:
While a punctured tire can be repaired through plugging, this should be avoided at all costs. The proper and best way to repair a tire is by patching the tire from the inside to fill the punctured hole.
The idea here is that plugging the tire doesn’t include removing the tire off the wheel for proper inspection. This means that a plug will be simply inserted into the punctured area and it can be very unreliable. The best thing to do is to have your dealer demount the tire from the wheel and have it fully inspected both internally and externally before patching and filling the punctured area from the inside of the tire.
Repairable and Non-Repairable
According to the DOT guidelines, any damage or puncture that is on the shoulder or sidewall area of the tire should not be repaired. Such punctures are considered non-repairable. Other non-repairable punctures include damages that extend deep into the belt edges. The best thing to do when you get such damages on your tires is to consider replacing them.
On the other hand, repairable damages include punctures that are through the tread provided that they aren’t too large.
This is where the USTMA and TIA come in. The industry-standard guidelines stipulate that tire repair shops can only fix punctures that are in the tread area of the tire and are up to a maximum of up to ¼ inch in diameter. This means that you shouldn’t repair any tire that has a puncture that’s larger than ¼ inch diameter. The best thing to do in such a scenario is to discard the tire and replace it with a new one.
The industry-standard guidelines also stipulate that the tire repair shop must properly and thoroughly evaluate what caused the puncture or damage, reestablish an airtight seal of the tire’s inner liner, and properly patch the damaged area of the tire.
More importantly, the repair limits and procedures should follow the recommendations and repair policies provided by the tire manufacturer. For example, the repair units shouldn’t overlap and the number of repairs on the tire should be limited to the manufacturer’s recommendations as well as the tire’s condition based on the inspection process.
Here are a few things that you shouldn’t do based on the industry standards.
- A tread puncture that is larger than 6mm (¼ inch) shouldn’t be repaired.
- A tire that has a 2/32 inch remaining tread depth is worn out and shouldn’t be repaired.
- A tire repair should not be done without removing the tire from the wheel and rim. An outside-only repair isn’t reliable and should be done for temporary use. Again, a specially-trained technician should remove the tire from the wheel and rim and carry out a thorough inspection for any internal and external damage.
- Do not repair a puncture on the sidewall of the tire or any non-repairable damage.
- Do not replace an inner tube as a remedy for improper repair.
- Do not plug a puncture from the outside of the tire without removing the tire off the wheel and thoroughly inspecting the tire for any major issues. Instead, remove the tire and patch the puncture from the inside. You have to make sure that the puncture is filled with suitable vulcanizing material or rubber and that the patch is perfectly applied to the inner liner to prevent air loss.
- Do not revert radial tires in an attempt to try to avoid the excessive spreading of the tires and tire beads.
- You shouldn’t do anything that exposes the tire casing body or ply cords as this can completely damage the tire and you’ll have to get a new one.
Tire Repair Statistics
According to statistics from DOT, 28% of all roadside emergencies revolve around tire issues. This means that motorists experience about 9 tire punctures every second in the United States. This then means that there are about 283 million flat tires in the United States every year.
Another statistic shows that an average driver in the United States is likely to experience at least 5 flat tires in their lifetime. So the possibility of being a victim of a flat tire and requiring tire repair is very high.
Tire Repair Process
This part of the article will take you through the step-by-step tire repair process. As a consumer or a car owner, it’s not a must that you know the step-by-step process but it can be critical if you understand a few things.
Consult a Tire Repair Specialist
Well, it’s also best to consult a tire repair specialist to get his/her opinion on whether repairing the tire is the best thing to do.
Again, before having anything done on your tire at the tire repair shop, it’s recommended that you check your vehicle owner’s manual to see their suggestion. You can also consider checking the tire manufacturer’s recommendation online. The idea here is that some tire manufacturers and carmakers will suggest that it’s not a good idea to drive a vehicle with a repaired tire.
Carry Out a Thorough Inspection
One of the first and most important things to do is to evaluate whether or not the tire can be repaired based on the guidelines provided by the DOT, USTMA, and TIA. Make sure that the damage is in the repairable area and within the recommended size of the damage.
You can only conduct a safe and proper tire repair after carrying out a thorough tire inspection. So before you begin the actual process of tire repair, make sure that the tire is removed from the wheel and rim and inspected for all unsafe conditions; both visible and invisible.
By removing the tire from the wheel and rim, you get the chance to carry out a thorough inspection both externally and internally to determine any other problem or damage that might be present. In short, the inspection process is of great importance in determining if the tire can be safely repaired and returned to the roads.
For example, when inspecting tires for light trucks, medium, or heavy trucks, it’s critical to understand the potential risks of zipper ruptures. These are circumferential ruptures in the sidewall that are generally caused by overloading the tires or operating with underinflated tires. Such conditions will make the sidewall over-flex and can result in overheating of the casing and calamitous tire failure.
As such, it’s always advisable that you inflate the tires, remove the valve core in a safety cage, and make sure that there’s nobody on the sidewall of the tire during the inflation process.
The recommended tools for tire inspection include:
- Rotary gouge to remove loose rubber
- Low RPM buffer
- Tire Spreader Light Kit
- Radial skive brush
- Protective eyewear
Locate the Puncture or Damage
Locate and mark the damaged area(s) externally and internally while also checking for tire separation. You can then use the TRT105 damage measuring tool to determine the size and angle of the damage. You should consider using a rubber cleaner and scraper to pre-clean the inner tire liner to remove the contaminants.
To use the TRT105 injury measuring tool, insert it into the damaged area of the tire. You should apply firm pressure to the handle while rotating it in a circular motion until it meets some sort of resistance.
Outline the damaged area and buff it using the appropriate repair template. You can use the low RPM buffer with a maximum speed of 700 RPM to outline the entire injury or damaged tire area. You can then use a 3/16-inch tapered carbide cutter to ream the injury. Make sure that it follows the angle of penetration from the inside of the tire. To ensure your safety, make sure that you have your protective eyewear on.
Make sure that you remove any damaged steel and rubber. You can use the carbide cutter with a low-speed drill of about 700 RPM. The injury should be drilled from the outside and then from the inside. You must make sure that the injury channel is not scorched.
Inspect the injury after completing the drill. This can be done by flexing the tire and probing the injury channel using a pointed awl. This is to ensure that all the loose materials and splits are entirely removed from the injury channel.
Clean the Injury Area and Apply Cement
To clean the injury area, you can start by using a cleaner fluid and a scraper but this won’t be enough. You should use a soft wire brush on a low RPM buffer to remove any buffing debris. You have to make sure that excessive pressure isn’t applied as this can alter the buffed texture, which can then interfere with the repair adhesion.
Alternatively, you can consider using a vacuum cleaner to remove all the debris but make sure that it doesn’t come into contact with the buffed area as it can contaminate the surface.
Repair, Installation, and Finishing
You should then remove the poly from the plug stem. Place the stem into the wire puller and coat the entire plug with the self-vulcanizing cement. Make sure that you place the poly in such a way that the cap isn’t contaminated to allow for easier removal of trapped air during installation.
Apply a small amount of self-vulcanizing cement to the black tapered portion of the stem. You should then relax the beads of the tire and push the wire puller through the injury from the inside of the tire while the self-vulcanizing cement is still wet. You can hold on to the wire puller using pliers and insert until the gray rubber on the plug becomes visible on the outside of the tire.
You can then press down the repair with your hand from the center out. With the poly still positioned under the cap, use a firm pressure to stitch the repair unit from the center out. You can then disengage the poly from the cap and press down the sides while using the firm pressure to stitch towards the edge of the repair. Make sure that this is done in the opposite direction to ensure that air is removed.
That’s not all; make sure that you remove the clear protective from the top of the repair. You can then seal over the buffed area of the inner liner and the edge of the repair using a reliable security coat. You can then cut off the excess gray rubber above the tread surface. You should cut the plug on the inside of the tire 1/8-inch above the inner liner. You have to be very careful to ensure that you do not stretch the plug during the cutting process.
You can then apply a bead sealer to the bead of the tire. This should be done before inflating the tire to ensure that there’s no air loss around the bead. You can also apply a light coat cleaner fluid around the buffed area to scrape clean and allow to it dry. Lastly, inflate the tire, cut the plug stem from the outside and the tire should be ready to return to service.
How to Use Tire Repair Kit
Modern cars are increasingly coming without spare tires. Instead, they come with puncture repair kits, which are designed to be a lot easier to use and are quicker than replacing a wheel. With that in mind, learning how to use the tire repair kit is an essential skill that every car owner should have up his/her sleeves.
Let’s be honest; no matter how your tires are new, large, solid, or how careful you are, things happen. And because your tires are your point of contact with the road, you should be prepared with a good tire repair kit and of course, know how to use it. Again, tires are not cheap, so learning how to repair them using a tire repair kit can save you some money. Keep in mind that a tire repair kit should be used mostly on tubeless-type tires.
The best part of using a tire repair kit is that it only takes 15 minutes to repair the tire unlike replacing the spare tire which can be quite challenging.
Get the Right Tools
If you choose to use the spare tire because you’ve had a puncture, you’ll have to use tools such as the impact wrench, torque wrench, chock, valve stem tools, pliers, and vehicle jack. On the other hand, modern tire repair kits are a lot easier to handle. All you have to do is choose between a two-step kit and a one-step kit.
A one-step kit is used by attaching the hose, which simultaneously injects both air and sealant. You must choose the right-sized tire repair kit, especially if you have a larger vehicle that needs more sealant and more power inflators.
Differently, you can choose a two-step kit that has a bottle of tire repair sealant and an inflator that is used to inject the sealant into the puncture before attaching the inflator to fill it with air.
Here are the crucial steps to follow.
Finding the Puncture
The first and foremost step is to find the puncture. As noted earlier, you shouldn’t attempt a tire repair if the hole or the crack is on the sidewall. This is simply because the sidewall is under a different form of pressure and using plugs on it will most likely cause it to blow. So if there’s a crack on the sidewall, you’ll have no other choice but to replace the tire with either a spare tire or a new one.
If you can easily locate the puncture, then using the tire repair kit will be very straightforward. But if you can locate it, then you’ll have to spray some soapy water on the tire and check for bubbles. The bubbles will be a result of air coming out of the tire from the punctured area. If there’s an object in that area, you’ll have to take it out using pliers.
Remove the Tire and the Valve Stem Core
Using the carjack to elevate the car above the ground, take the flat tire off. You have to find the perfect lifting points so that the jack doesn’t damage the car. Keep in mind that carjacks aren’t the safest of tools since they aren’t strong, so you shouldn’t crawl under the car.
You can use the impact wrench and impact socket to remove the wheel lugs. Make sure that you place the lugs in a safe place so that you do not lose them. You can then remove the valve stem core and deflate the tire.
Use the Tire Repair Kit
Now that you’ve located the puncture and removed the object that caused the puncture, you can now enlarge the crack or the hole with a rasp to ensure that the plug fits in. Attach the tire repair kit to the T-handle insert tool and inject it into the hole or crack.
You can then pull out the T-handle slowly and carefully and trim down the parts that stick out. You should now re-inflate the tire and check whether there’s still a hole.
Ream Out the Puncture
Reaming out the puncture is of great importance as it helps in receiving the tools. Use the reamer in the equipment by inserting it into the hole and twisting it a couple of times.
Thread the Plug Tool
Take a stick tar in your equipment, peel it off, pinch the end of the worm, and thread it through the tool in your equipment that resembles a giant needle with an eye. You’ll have to pull it through so that it’s positioned at the center of the plugging tool.
Apply Rubber Cement
You can clean the puncture area using rubber cement. Just apply a few drops of the cement on the tip of the puncture and insert it into the crack. Twist it from one side to the other and then upside down.
Plug the Leak with a Patch
To plug the tire leak with a patch, you’ll need a holder, plugs, and contact cement, which are all included in the kit. Apply the cement on the plug and insert it into the crack so that it can lubricate the hole. Insert the utensil into the crack and push the patch in the puncture channel. You can then pull out the utensil so that the plug remains stuck in the crack. You can then cut the sticking part so that it’s on the same level as the treads.
You should note that there’s a difference between a plug and a patch. A plug is a lot easier to do and will take less time and can be done without necessarily removing the entire tire. The main downside of a plug is that it won’t last long and that’s why it’s not recommended by tire experts.
On the other hand, a patch is a comprehensive tire repair process that involves removing the tire and mending the puncture from the inside. While it will consume much of your time, you are guaranteed that the repair will be reliable and will serve for a very long time.
Fix the Puncture and Inflate the Tire
The puncture should be fixed now that you’ve inserted the plug into the hole. And because you let the air out of the tire, you should now re-inflate it using a handheld pump, a compressor, or an air compressor machine at the gas station. Make sure that you inflate it with the right tire pressure as recommended on the car’s owner’s manual.
You can then remount the tire, put back the lugs, and hand thread them as far as you can. You can remove the jack and tighten the lugs using a torque wrench. Once you’ve finished everything, the car should be ready to go. Just make sure that the tires are balanced and rotated to extend the tire’s life.
How Much Does It Cost to Repair a Tire?
On average, the cost of tire repair may cost you between $15 and $30 depending on your location but there’s more that goes into that than just a few dollars that you may have to spend for having a puncture. In fact, some tire dealers may choose to repair the tire for free as a form of after-sales services if you purchased the tire from them.
In addition to costing you a few dollars, a puncture can be inconvenient and will most probably derail a trip. Of course, it’s possible to plug the tire on your own and this may cost you a few dollars less but you’ll have to be properly prepared for this relatively common emergency. This means that you must have all the tools required including a tire repair kit, a jack, a lug wrench, and probably a spare tire.
But because your spare tire is most likely to be a donut tire that you can only use for a few miles, you’ll eventually have to patch the punctured tire provided that it’s still in great working condition. You also have to keep in mind that patching the tire will be a lot cheaper than going for a new tire.
While the cost of repairing a tire may be quite affordable to many car owners even if you're willing to have it repaired by a tire specialist, the biggest variable in the entire equation is perhaps the time that it takes to do the process. On average, it would take about an hour to have the tire repaired and this may depend on the severity of the damage.
So if you have the necessary tools and are willing to take the time to learn, then you can save a lot of time and money in the long run. After all, tire repair is a straightforward process if you know what you’re doing and have the right tools.
How to Repair Tire Sidewall Damage
Although it may be tempting to repair sidewall damage of your tire, tire experts often advise that you shouldn’t even try repairing any damage on the sidewall of your tire. This is because it’s a very risky endeavor given that the sidewall of the tire functions quite differently than other areas of the tire.
By attempting to fix any damage on the sidewall of the tire, you’re just offering a temporary solution that may become calamitous as the tire will most likely break or even explode, thereby putting you and other road users in danger’s way.
More importantly, it’s not even safe to drive on a tire that has a damaged sidewall. That being said, the best thing to do when you have a tire with a damaged sidewall is to go to the nearest tire retailer and get a new tire or call for roadside assistance.
How to Repair a Tubeless Tire
It’s quite difficult to get a flat tire if your tires are tubeless. This doesn’t mean that you can get problems with your tubeless tires but it’s just rare to get a flat tire if the tires are tubeless. This is because tubeless tires have sealants inside them that instantly seal small cuts or holes that will prevent air from coming out while keeping your tires rolling.
However, sudden impacts such as hitting a sharp rock or nail can make your tubeless tire go flat, and you’ll need the necessary skills to have them fixed, especially if you’re on the road.
Here is what you need to do.
The Puncture Repair Kit
A tire repair kit for a tubeless tire will come with the following:
- A spiral probe to clean and expand the tire hole or crack
- A packet of tire repair strips
- A tube of rubber cement
- A split-eye insertion tool to insert the tire repair strip
While the above-mentioned tools are the minimum tools that come in the tire repair kit for a tubeless tire, you’ll also require pliers to pull out the object that caused the puncture and a knife to cut the excess strip. You should also have a handheld pump to fill the air, especially for emergencies given that you might find a puncture far away from a gas station and may not be able to access the air compressor.
- Locate the punctured area and remove the object that caused the puncture
- Insert the spiral probe into the crack and rotate it in all directions to clean while also expanding the hole
- Insert the repair strip in the eye of the split-eye insertion tool
- Pull the repair strip through the eye and make sure that both sides of the repair strip are equal in length
Repair the Puncture
- Apply a few drops of rubber cement to the spiral probe and insert it into the tire to cover the puncture
- Remove the spiral probe and insert 2/3rd of the repair strip into the crack with the aid of the split-eye insertion tool
- Twist the insertion tool all over the hole before pulling it out. The repair strip should plug the puncture hole and come out clean.
- You can then use the knife to trim the excess length of the repair strip that’s protruding to the level of the treads.
Fill the Tire with Air
You can then attach the handheld air pump to the tire’s valve and fill it with air. This entire process of repairing a punctured tubeless tire should take about 20 minutes.
How to Repair a Run-flat Tire
While the USTMA recommends the same tire repair procedures for both run-flat tires and non-run-flat tires, there’s still no industry consensus on whether or not a run-flat tire can be repaired. Most arguments are based on the fact that run-flat tires have a unique construction that makes them more challenging to mount and demount.
That being said, whether or not you can repair your run-flat tire should depend on what the manufacturer recommends. After all, the USTMA recommends that tire owners should consult their tire manufacturers for their repair policies. For example, Michelin allows its run-flat tires to be repaired, while the BMW owner’s manual stipulates that its OEM run-flat tires shouldn’t be repaired.
The table below shows what manufacturers say as far as repairing run-flat tires is concerned.
The above table shows tire manufacturers’ policies on run-flat tire repair. Needless to say, the guideline will depend on the tire manufacturer as well and the vehicle manufacturer. It’s, therefore, important that you abide by these guidelines.
But in instances where a repair on a run-flat tire is recommended, you should repair the run-flat tire by filling the punctured hole from inside. You can then apply the patch on top of the repair. You should avoid plugging the tire as this doesn’t involve taking the tire off the wheel for proper inspection for further issues.
And if you cannot meet the above criteria, you can simply consider replacing the damaged run-flat-tire. This may, however, be costly since most tire manufacturers recommend replacing all four run-flat tires at the same time.
How to Repair Broken Tire Beading
A tire bead is that part of the tire that places it securely onto the rim. The tire bead must be airtight and if there’s any leak, the tire will fail. A tire bead cannot be repaired if the cords are cut or sliced and your only solution will be to replace the tire. But if the cords are intact and showing, then you can repair the tire bead.
Here’s what you should do.
Clean the tire rim and the bead thoroughly to remove any contamination that may prevent the bead from sitting properly on the rim. You can then apply a tire bead sealant to soften the bead rubber and enable it to conform uniformly to the rim.
You can then apply the RTV silicone compound to the bead and let it dry for a couple of days. This is to let it cure any damaged area. This will make the bead symmetrical so that it can fit easily and normally.
How to Repair a Leaky Tire Valve
When it comes to repairing a leaky tire valve, it’s important to determine if your tire’s valve stem is leaking or not. If the valve is leaking, you can consider replacing it for $20 to $30.
If you just want to repair a leaky tire valve and do not want to spend a few dollars on a new valve, you’ll require a couple of tools including a valve stem tool and a replacement valve core.
You can then determine whether the tire valve is leaking or not. Just take soapy water and pour a little mixture over the valve stem. If bubbles form over the valve, then it means that the valve is leaky and the air is escaping. If air is not escaping, then it means that the valve is okay and you should look for a slow leak in another part of the tire.
If the valve is leaky, you should deflate the tire and use the valve stem tool to unscrew the valve from the tire. You can then use the tapered end of the valve core tool to clean the valve stem. Ensure that the valve is thoroughly cleaned and any debris or obstruction is removed.
You can then install a new core into the valve stem using the valve stem tool. Tighten the new valve by hand but do not over tighten as it can potentially damage the new core, making your repaired valve leak. Once you’ve tightened the valve, you can reinstall it back to the tire, re-inflate the tire and replace the valve cap. This superb video can offer great insights on how to go about this entire process.
About THE AUTHOR
I've spent many years selling cars, working with auto detailers, mechanics, dealership service teams, quoting and researching car insurance, modding my own cars, and much more.Read More About Charles Redding