or some reason, my co-workers always call me when they get a flat tire.
Their reasoning seems to be that I'm good with computers, which are always
breaking down. Cars break down too, so they're basically the same. Even
people with advanced STEM degrees seem to be baffled by this technology,
so here are some tips for my scientific colleagues and others for whom
changing a tire is a form of dark magic.
If you're a car mechanic, these tips might seem obvious. But I can attest that there are many people who don't know them.
Rule #1: Avoid getting a flat
One co-worker told me she relies on auto-braking to avoid colliding with other vehicles. One day she was watching a train running parallel to the road while driving, so she ran off the edge, hit a pothole, and got a flat. (I made a mental note: never let this person drive me anywhere!) One reason for the flat was that her tires were almost completely bald. The loss of rubber weakens your tire and makes it more likely to get a flat when you hit a pothole.
Tire tread test. If small rocks don't get stuck in your tire, it means the treads are too worn and you need new tires. (Note: not the standard way of testing a tire)
There is an unwritten rule in the universe: whenever there is a pothole in your path, there's always a car coming the other way that prevents you from swerving to miss it. I have never seen this rule to fail.
If your car slips when it's raining, it means you need new tires. If the tire has a bulge anywhere on it, it's telling you it doesn't want to live anymore and it doesn't want to die alone. Keep the tires properly inflated, too, otherwise when you hit that pothole it could dent your wheel as well as giving you a flat.
Rule #2: For God's sake, get off the road
There is no law that says you have to change your tire the minute it goes flat. If it's safer to drive home, do that. No tire is worth risking injury for. Chances are the tire is already ruined anyway. If you decide to change the tire, get your car completely off the road. Never try to change a tire while any part of your car is on the shoulder. I've seen people passing each other on highways by driving at 80 MPH on the shoulder. They won't see your car in time, and they'll certainly never see you. I've also seen cars parked on a curve with some guy crouched down changing a tire, oblivious to the risk. Don't be that guy.
If you must stay near the road, put some traffic cones in front of your car. They're cheap and nobody ever steals them. Other drivers might not see you, but they're programmed to fear traffic cones.
If you cannot drive the car, do not stand near the car. Stay as far from it as you can get, behind a guardrail if possible, preferably in another county.
Rule #3: Go somewhere safe
If you're in a rural area, there will be stray dogs that see you as encroaching on their territory, and they will bite you. In a city, there are many bad areas. The humans will not necessarily bite you (though they might), but they can do other things. It is better to keep driving and ruin the tire than to risk meeting a criminal.
Don't change your tire in somebody's driveway. In many areas, people have driveway alarms. There are people who become enraged to see someone in their driveway and they might come outside and threaten you with a firearm. Or they might invite you in for pie, you never know. This is America, baby!
In general, if the tire is punctured on its tread it can sometimes be saved. If the hole is on the sidewall, it can never be saved. In my experience, the universe's rule of “whatever doesn't kill you will do the next best thing” applies, and the tire is usually already ruined by the time you manage to get off the road.
If you have AWD or 4WD, you will most likely have to replace all four tires because tires of slightly different diameters will put stress on your differential, which is bad for it.
Rule #4: Carry a real spare tire
Most cars come with a space saver tire. It is there because the government demands that manufacturers have a certain gas mileage, so they make gas tanks as small as possible and rarely provide a spare tire. A space saver is not something you can use except in a dire emergency. Your handling will be compromised and you can easily crash.
My strategy is to buy an extra set of wheels and put snow tires on them, then carry one snow tire in the trunk. It's easier to change them at home when it starts to snow instead of hoping you can get through the snow to a repair shop on your summer tires. This pays for itself in a few years, as it's very expensive to have snow tires changed twice a year.
Rule #5: Practice changing a tire at home first
A car usually comes with a jack and a small lug wrench. These tools aren't always enough: car mechanics often use a hydraulic wrench that makes it nearly impossible to remove the nuts. Many times I had to literally jump on a breaker bar several times to get them loose.
Additional tools needed:
A breaker bar, cheap enough at any Harbor Freight. You need to know which drive size you want. The drive is the little black square thing on the end that fits into the square hole on a socket. There are many different drive sizes; 3/8, 1/2, and 3/4 inch are the most common for cars. If in doubt, standardize on 1/2 inch. You can even buy a torque adapter, which turns your breaker bar into a high precision torque wrench. It has an LCD display with many buttons, so if you're a guy you obviously need one.
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Two SAE impact sockets. The socket size (5/8 and 9/16 inch shown) refers to the inside diameter of the hexagonal end, which is different for each socket. The drive size refers to the square end (in this case a 1/2 inch drive), which is constant. The square end fits on a socket wrench, breaker bar, or torque wrench and is usually held in place by a little ball bearing on the wrench
A socket. A socket is a steel cylinder about an inch long with a hexagonal hole in one side and a square one in the other. The wrench or breaker bar attaches to the side with the square hole. When you buy a socket, make sure it has the same drive size as your breaker bar and that it is the right size for your lug nuts. If it's too big, it will strip them. Only get a six-point (hexagonal) socket; a 12-point socket is no good and will strip your lug nuts. There are many types: SAE or metric, impact or regular. Auto parts stores will happily test them for you, or you can buy a whole set.
A big four-way lug wrench This type doesn't use sockets, but has four fixed sizes. The crossbar makes it a lot easier to spin that baby around, which not only gets the nuts off faster but also makes it look like you know what you're doing. Watch out: there are several sizes. Some are metric, some SAE, some are larger sizes for SUVs.
Torque wrench Very useful when tightening the lug nuts to get them equally tight. A torque wrench must never be used to loosen nuts; it will break. Set the torque to whatever foot-pounds (or newton-meters) are specified in your car manual. It attaches to a socket, so make sure you get the correct drive size.
Locking gas cap with a tether. While not technically needed to change a tire, it's essential if you leave your car at a garage. Some garages happily leave your car outside and unlocked because they despise those car alarms that can't be disabled. That means you'll come back to find your tank mysteriously empty. In my case they also left the gas cap loose, causing the Check Engine light to come on. Without a tether, it would have fallen off entirely.
Jack A jack is usually included in your car. You can damage your car by using it wrong. Your car will have a narrow rigid steel rail on both sides that you can feel with your hand. The top part of the jack has a notch that fits into the rail. This prevents the jack from sliding off. Check your jack every few years to make sure it hasn't rusted.
Traffic cones Two at least. Humans fear them.
Rule #6: How to change a tire
Once you're at a safe location, put the car in park, turn off the engine, and set the emergency handbrake. If you don't know how to do this, it's essential to learn. Leaving a car in park puts the entire weight of the car on the gears, which is bad. If you leave the car in neutral, the wheel will spin around when you jump on the breaker bar, which is worse. Or your car will roll off the jack and head back into the street, possibly smashing your hand or running over you, which is really bad.
Set up your cones and make sure the jack is on a stable surface. Position it close to the tire that is flat so that it's between the front and rear wheels. Make sure the slot on the jack fits in the strong rail under your car. If you place the jack anywhere else, it will damage your trim. Insert the back end of the wrench that came with your car into the hole in the jack. Raise the car so that the bottom of the tire is at least one inch above the ground. This means raising the car by several inches. Remove the lug nuts and put them somewhere safe. Don't let your fingers get between the wheel and planet Earth at any time no matter what. Gravitational forces can accelerate them toward each other at surprising speed.
If you can't loosen the lug nuts with the wrench, you need your breaker bar. Attach the socket to the bar and push down on it to encourage the nut to rotate counter-clockwise. If that doesn't work, use your foot. You might need to apply a lot of torque; the rules of physics say it's easier if you're overweight and if the breaker bar is longer. It's important to orient the breaker bar so that you push it down; don't try to pull it up.
Put the new tire/wheel onto the car and push it in as far as it will go. It will only fit in one direction—hubcap pointing out—so it's hard to put it on backwards. Then put the lug nuts on, one at a time, and tighten them clockwise. It's best to do alternate sides. Then re-tighten each nut: when you do one, the wheel settles into its slot, making the others loose.
Rule #7: Have a portable air pump
You'd be amazed how many people drive around not knowing their spare tire is flat. Or maybe they come back to their car and find a tire very low. You can buy small tire inflator air pumps that plug into your cigarette lighter, or accessory plug, or whatever they're called now. You'll also need a tire pressure gauge even though there may be one on the pump.
Do not try to plug the pump into the USB port. This is totally different!
Check your car manual before buying; some pumps draw too much current and will blow the fuse in the cigarette lighter plug. If you're unsure, you can get a cable with big alligator clamps that will attach to your battery. Usually there is also another fuse inside the cables that attach to these pumps. If the pump doesn't work, you might have open the little black thing on the cable and change the fuse. Keep the pump wrapped in a plastic bag when not in use so it doesn't get rusty.
There are also manual pumps that can be operated by foot. These aren't terribly reliable either, and I recommend carrying around one of each type.
sep 13 2023, 11:22 am. edited for brevity 4:00 pm. updated sep 14, 2023, 6:50 am
