Tire Repairs: In the Field Know-How
May 18, 2017
Stop! I'd heard the unmistakable hiss of a punctured tire losing air and alerted my partner, who was driving the Ford pickup we were using to conduct road surveys in southern Nevada. Our job took us down scarcely used tracks with significant incursion from creosote bushes, which leave vicious little daggers sticking out around the base of the plant as the perimeter dies off. This was our third puncture today — and it was not yet 8:00 in the morning.
Only two minutes later we had the tire repaired and had resumed collecting GPS data. We didn't even bother to add any air, much less take it off and replace it with the spare.
Tire failure is by far the No. 1 cause of vehicle breakdowns in the backcountry — whether you are exploring Nevada or Namibia.
Yet I'm astonished at how many people still rely on a single spare and maybe a can of Fix-A-Flat as backup on remote excursions far from AAA.
The irony is that the farther you are away from well-traveled routes and outside assistance, the higher the possibility of running into projecting root splinters, knife-edged rocks, or even an off-camber rut that can pop a tire bead right off the rim and deflate it instantly.
Why not be prepared and self-sufficient? With a few tools, a good air compressor, and a proper repair kit, you'll be able to repair any tire mishap short of a shredded blowout and be on your way.
Most tire problems result from simple punctures in the tread area, where the tire actually contacts the ground. Close to civilization, likely culprits include nails and screws, broken glass, and the like. Farther afield, you might run afoul of those creosote daggers or any number of other biological or geological hazards.
At higher speeds, punctures typically occur on the rear tires — the front tire rolls harmlessly over a nail or screw lying flat, but pops it into the air where it can land pointy- end-up just as the rear tire passes.
At low speeds, it's more often the front tire that will find some projecting bit. A nail that embeds itself in a tire might not make its presence known for hours, since it forms a partial plug and slows deflation.
A root end will more likely puncture and pull out, causing rapid loss of air and, possibly, an audible warning.
The easiest and quickest way to repair a simple puncture is with a plug kit (which is what we used in Nevada).
A tire plug comprises a short length of rubber-adhesive-impregnated nylon yarn, which is inserted into the puncture with a special tool, after reaming the puncture with another tool.
Cheap plug kits are available everywhere; higher-quality kits with sturdier tools and better plugs come from Safety Seal and ARB.
By far the most comprehensive tire repair kit I've used is the Ultimate Puncture Repair Kit from Extreme Outback, which includes not only plugs but also an exhaustive assortment of patches, spare valve cores, valve stems, a valve core tool — everything you'd need to be self-sufficient on any trip up to and including a global circumnavigation.
So there you are at the side of the trail with your plug kit and a slowly collapsing tire. You can jack up the vehicle and remove the tire and wheel if access is limited or leave it on and slowly roll the vehicle while looking, listening, or feeling for the source of the leak.
Let's assume you spot a nail head embedded in the tread. Make sure the leak is accessible for your repair tools, then use a multi-tool or pliers to remove the nail — which will immediately make the leak speed up.
The first step to repair the hole is completely unintuitive: You're going to make it bigger, so the plug can fit. Insert the toothed reamer into the hole — it might take some real shoving — then work it in and out briskly a few times.
Don't be gentle.
If the puncture is in the tread area you'll be able to hear and feel the steel belt as the reamer rasps through it. Once it moves back and forth easily, set it aside.
Pull a plug out of its packaging, flatten one end with your fingers, and insert it to its midpoint into the eye of the insertion tool.
You'll have to pull quite strongly to get it in there. Hint: Doing this ahead of time is smart. Insert the tip of the tool and the plug into the puncture.
Again, you'll need a strong shove to get the tip and the doubled plug into the tire. Push until just a half-inch or so of the tips of the plug show above the tread, then pull the tool straight back out. The cutting edge of the eye will first pull the middle of the plug back into the puncture, packing it tightly with vulcanizing material.
Then cut the plug so the tool pulls free, leaving the plug in place and the puncture instantly sealed — no waiting for glue to dry. Trim the plug as flush as possible with a knife or razor blade, and you're finished.
The tire manufacturer will warn direly that this is a temporary repair, but I've known tires with just a few hundred miles on them repaired thusly that went on to live out their full tread life.
What if the hole is larger in diameter than one plug will seal? Try two'¦or three'¦or four. My friend Tim once repaired a sidewall split with no fewer than five, and it got him back to civilization.
While we're on sidewalls, note that a plug repair there really should be considered an emergency fix only. The sidewall, even on a sturdy all-terrain tire, lacks the structural integrity of the belted tread area; it's designed to flex and can't support the plug as well.
Nevertheless, a sidewall plug repair should hold just fine for the length of a trip.
Tim's five-plug repair notwithstanding, a much better way to repair a sidewall split (sidewalls collect splits from rock gashes and pinching just as often as they do simple punctures) is with a patch on the inside of the tire. To do that, you'll need access to the inside, which means you'll need to break the bead, a procedure that sounds alarming but really doesn't break anything.
The inside edges of an automobile tire, where they grip the rim of the wheel and seal the air inside, are each reinforced with a very stiff wire cable embedded in thick rubber: the bead. The wheel is made with a corresponding groove running around its inside and outside edge.
When your local Discount Tire store tech mounts a tire, his fancy machine first levers the tire over the rim so the beads are inboard of the grooves.
He then applies a sharp blast of high-pressure air, which pops both beads outward and into their respective grooves. The tire can then be fully inflated. The grooves hold the beads very tightly — even running for some time on a flat tire will rarely unseat them.
When your tech needs to remove a mounted tire, his machine pries the beads loose with a powerful automatic lever. In the field, you'll need to be more creative.
Trust me, just jumping up and down on a deflated tire won't work. (Important note: Those of you with shiny alloy wheels — or shiny steel wheels for that matter — will find that some of the following techniques might scratch and gouge them. I hereby absolve myself from responsibility.)
The first step is to remove the valve core to ensure the tire is completely deflated and to easily let out additional air as you compress the carcass. Mark the tire and wheel with chalk or anything handy, to make sure you reinstall it in the same place and don't mess up the balance.
To "break" the bead you need to apply inward force to the sidewall of the tire as close as possible to the edge of the rim. One effective way to do so is to lay the tire and wheel on its side under your vehicle's bumper, then position a Hi-Lift or bottle jack with the base plate on the tire and the lifting tongue or post under the bumper.
Crank up the jack and the base plate will push the bead out of its groove. You generally only need to do this in one spot as the bead will easily pop out of the rest of the groove when stood on.
Break the bead on the outside of the wheel first; the groove on the inside has a ramp that makes it more difficult.
An elegant enhancement to the Hi-Lift technique is the Extreme Outback Beadbuster, which attaches to the jack's base plate and incorporates a curved spade to precisely bear against the tire close to the rim, reducing stress on the sidewall.
The opposite, cruder, end of this spectrum is to lay the tire on the ground and simply drive over one edge of it with the help of a spotter. Effective, but a bit hard on the tire.
By far the quickest — and most stylish — way to break a bead is with the Australian-made Tyrepliers.
This cunning tool, which adjusts to fit wheels up to 19 inches in diameter, frees the bead using good old Archimedean leverage. It's nearly foolproof, and so universally respected that it carries a NATO stocking number.
I've lost count of the onlookers and students I've amazed by popping the bead on a tire in about ten seconds flat. You stand on the tire and use one foot to push the fixed hook of the tool under one edge of the rim, then work the lever hook under the opposite side with the paired handles.
Push down on the lever handle and voilÃ¡. It's fast. You're bearing only on the actual bead, so damaging the sidewall is virtually impossible.
Once the outside bead is free, turn the tire over and do the same to the inside bead.
The tire will now be loose in the well of the rim, but you still will not have access to the inside of the carcass.
For that you'll need a pair of automotive tire irons, which look like, and are, just butched-up bicycle tire irons about two feet long and work exactly the same way.
Start near the valve stem, insert one iron and lever the tire over the wheel edge.
Insert the next one near it and lever that section of the tire over.
Leave the first iron in place as you proceed around the tire until it pops free.
With one side of the tire off the rim, you'll have adequate access for most repairs; if not, you can use a tire iron and a dead-blow hammer to take the tire completely off the wheel.
If the sidewall split is short, you can simply patch it from the inside; again think glorified bicycle repair. The patches in the Extreme Outback kit cover a range from small to terrifyingly huge.
If the split is severe, you'll want to stitch it to hold the edges together and reinforce the patch — yes, more or less like a surgeon would do with a bad cut.
I use a cordless drill, or an awl with a cutting edge, to make a line of small holes on both sides of the split, then stitch it together tightly with whatever is handy.
Small-diameter wire works best; heavy fishing line works too but is difficult to knot. (I've heard of people using dental floss, which might work if it were tripled or quadrupled.)
With the slice secured, you can roughen the area behind it, spread cement on both tire and patch, wait until dry, then apply (obviously your patch needs to cover the stitch holes).
This is another repair to be considered only in a fix-it-or-walk-home situation, but I know of stitched tires surviving dozens of rough miles.
Incidentally, if you have a tire off the rim and you've done any plug repairs, note that now is a good time to reinforce the plug with a patch behind it for ultimate security.
Now you have to put everything back together. Starting this time opposite the valve, use the tire irons to pry the bead or beads over the rim and back into the well of the wheel, so you have a loose tire completely inside the rims.
Remember the fancy machine the tire tech used to blast air into the tire and seat the beads? Again, we're going to improvise.
There's a long-standing myth that you need a very large volume of air (or hold-my-beer pyrotechnics with starting fluid, see later), to reseat beads.
But I've done it with very small compressors and proper technique — as long as the wheel is not too wide for the tire.
If you run showpiece alloy wheels ten or twelve inches (or more) in width, so your tires' sidewalls barely protrude past them, you might have a devil of a time reseating beads in the field — and you'll also stand a much greater chance of damaging a wheel rim on the trail, since there's no protection offered by the sidewall.
The wheels on our Land Rover 110 and FJ40 Land Cruiser are 6.5 and 7 inches wide respectively, and I can easily reseat beads on 255/85/R16 BFG tires (higher-profile tires help as well, with their more flexible sidewalls).
I mentioned that I'd reseated beads with very small compressors, but the greater volume of air you have, the easier and quicker the process will be (see sidebar on compressors). A CO2 tank will work very well, but be aware that CO2 can leak out of tires over time.
Here's how it's accomplished. Stand the tire and wheel upright'º and center the tire as evenly as possible in the wheel with your chalk marks aligned.
If tire and wheel are well matched, the tire's beads will naturally bear against the inside of the grooves and form a partial seal on their own.
Use water, with some detergent in it if you have it, to thoroughly soak the perimeter of each bead (this functions more as a lubricant than a seal).
In a pinch any liquid is better than nothing — my nephew reports that Keystone Light beer works well, which is as far as I'm concerned the best possible use for Keystone Light.
Your valve core is still out, right? Apply the air chuck to the valve and start inflating.
If the tire is not centered properly you'll see a lot of bubbles in one spot; stop and reposition.
If the seal is good you'll see the tire's walls expand slowly until, with a rather alarming metallic PING, they will seat in turn, usually the inside one first because of the ramp.
Release the chuck — air will rush out but the beads will stay put. Reinsert the valve core, inflate, and you're finished.
Some bush mechanics suggest running a ratchet strap around the circumference of the tire and tightening it prior to setting the beads, the idea being that it will push the beads outward and make sealing easier.
I've tried it with and without and never noticed a difference, even with a big strap.
The other seating technique is the infamous starting-fluid routine, which involves spraying starting fluid or another flammable aerosol around the bead of the tire lying on the ground, then tossing in a match to create a minor explosion that blows the beads onto their grooves in a split second.
When this works it is a crowd-pleasing spectacle, but search YouTube for videos and you'll find plenty of crowd-pleasing, spectacular failures as well. I prefer the more civilized approach.
There is another situation in which you might find it necessary to reseat a bead. Occasionally on very rough trails a rut or rock will catch the side of a tire with enough force to knock a bead loose and produce a startling whoosh as the tire deflates. This seems somewhat more likely to occur if you have aired down to enhance traction (or if you've been indulging in a bit of Baja 500 hooning).
Frequently only one bead — usually the outside one — will be pushed off. While it is sometimes possible to reseat the bead with the wheel still on the truck, you might find it necessary to remove the wheel and actually unseat the opposite bead to get the tire to sit properly for reseating with an air compressor.
Once you've mastered the art of demounting tires and reseating beads in the field, dealing with simple punctures will seem like child's play.
That day in Nevada? If memory serves, we collected four more punctures before the day was out, and each one was repaired in a couple of minutes.
We never even considered putting on the spare tire. That would have been way too much work.