How To: Basic 4×4 Repairs – Tyre Plugs
The quickest and easiest way to sort out a flat tyre in the bush is to plug it. Here’s how to use tyre plugs.
MOST MODERN four-wheel drives run tubeless tyres, which means if you get a puncture through the tread area you can plug it with a self-vulcanising repair cord. While this method of tyre repair is not recommended as a permanent fix, it’s definitely one of the quickest and easiest ways to get going again.
To plug a tubeless tyre you’ll need a quality tyre repair kit and an air compressor. If the tyre needs to be removed from the vehicle to effect the repair, you’ll also need a jack and wheel brace.
If you’re driving on the road chances are you’ll feel the effects of a deflating tyre before it’s damaged beyond repair. This can be more difficult to detect when driving off the road, but sometimes you’ll hear the air escaping from the tyre. Consider equipping your vehicle with a Tyre Pressure Monitoring System (TPMS) if it doesn’t already have one; these cost a few hundred dollars but that’s money well spent if just one tyre is saved by early puncture detection.
Once you’ve found somewhere safe to pull over, get out of the vehicle, go to the damaged tyre and look for the puncture point. Sometimes the culprit will be readily visible (whether a nail, screw, stick or other sharp object) and sometimes it will be hidden from view, in which case you’ll have to listen for the puncture. If you can’t hear it, have someone move the vehicle slightly, as the puncture may be at the bottom of the tyre.
Once you’ve found the puncture point, ascertain whether the tyre needs to be removed from the vehicle to make the repair or if it can be performed in place. Ensure the vehicle is in gear with handbrake applied and chock the wheels before jacking it up or repairing the tyre in place.
If the tyre is totally deflated, you’ll need to pump some air into it to make the repair. Once it’s back up to a reasonable pressure, remove the offending object using a pair of pliers and insert the reamer tool. Force the reamer tool in and out a few times until it moves freely, which will make the hole big enough to insert a plug. Leave the reamer tool in the tyre.
Apply some lubricant (supplied in the tyre repair kit) to a self-vulcanising repair cord (plug) and thread it through the eye of the insertion needle, then liberally coat the cord with the lubricant. Remove the reamer tool from the tyre and insert the loaded insertion needle into the hole in the tyre to prevent air escaping.
Sometimes the loaded insertion needle will go into the tyre without too much effort; sometimes it will require a lot of force. If you’re struggling to force the plug into the tyre, you might have to pump more air into it. If you’re still not having any luck, you might have to remove the wheel from the vehicle so you can exert more force on to the insertion needle.
Once the plug has been inserted into the tyre, hold the insertion needle’s collar down on the tyre then extract the needle. Listen for air leaks, then coat the area in soapy water and look for bubbles. If you don’t have soapy water on hand, saliva is a great substitute.
If air is still escaping from the tyre, you’ll have to insert another plug (sometimes more). If there are no leaks, ensure the tyre is inflated to the desired pressure, refit the wheel to the vehicle (if it was removed) and resume your journey. Keep an eye on your TPMS to see if the tyre is holding pressure or, if you don’t have one fitted, physically check the air pressure 10 or so minutes up the road/track. And check it again the following morning.
Although the tyre repair method outlined above is usually very effective, as soon as practicable you should remove the tyre from the rim and inspect the tyre for internal damage.
If the initial puncture was not detected early enough, there’s a chance that the tyre may have suffered damage around its sidewall area. This can often be seen by simple external inspection, but sometimes the damage can only be detected internally.
If the tyre is deemed to be repairable, it should either be plugged from the inside or a vulcanising patch should be applied to the punctured area. If you’re not confident you can perform this type of inspection/repair yourself, enlist the services of a tyre specialist.
Out of bounds
You can only plug a tubeless tyre on its treaded area. Never try to plug the shoulder or the sidewall, as the plug will fail which could result in a rapid deflation and loss of vehicle control.