First things first: do NOT drive on a flat tire any more than absolutely necessary. That is, long enough to pull off to the side of the road, or to get away from the psycho zombies that are chasing you in their car. Nobody wants to be a zombie, or become the ‘B’ position in a human centipede, so go ahead and drive the hell out of that flat tire if you’re in danger. Short of that, pull the hell over. Safely, obviously – don’t cut off that semi-truck and get plowed into.
Driving on the flat can do a couple things. First, you can significantly damage the sidewall of the tire. That’s the bit that doesn’t have tread, and isn’t meant to be used as a driving surface. With a flat, you’re pinching the sidewall of the tire between the road and the dull edge of the wheel (or “rim” if you’re into Hondas with wings and catfish mouth-style grilles). Driving like that, the wheel constantly rolling on the sidewall with the weight of the vehicle, you can quite literally shred the sidewall of the tire. Something like that cannot be repaired, so if you do that you’ve guaranteed yourself buying a new tire. A new tire will easily run you about $100 or more if you have some special or uncommon size/brand on your vehicle. If you’ve only run over a nail or something simple like that, and that nail is in the treaded portion of the tire, that simple puncture can be repaired for probably less than $20. So remember: sidewall damage equals shiny new tire, puncture in the tread equals cheaper patch and repair.
Second, driving on the flat can damage the actual wheel on your vehicle. You could dent it, scratch it, or destroy it other interesting and fancy ways. Beyond cosmetic stuff, you run the risk of damaging it to the point of it not being able to hold a tire any more. So not only do you need to buy a new tire, but now you need to buy a new wheel. And if you think aftermarket wheels are expensive, just wait until you price an anything-other-than-basic-steel factory wheel from the dealer. Even those can be pricey. So again, unless you’re just itching to drop a few hundred dollars, pull the hell over when you have a flat.
So how do you know when you have a flat? There are a few warning signs that you’re about to be late to work, or wherever you may be headed when this happens. And you will be headed somewhere that you need to be. The odds of you getting a flat tire at a convenient time are probably slightly better than winning the Power Ball, but not by much.
First you’ll get a low-pressure warning if your car is equipped with such fanciness. “But wait,” you say, “I’m still cruising my vintage mid-90s car that doesn’t have those sensors,” or “But those sensor systems went out years ago!” Well, don’t worry because that tire pressure sensor warning is only going to give you a couple minutes of notice anyway, if you’re lucky.
You’ll notice that your car is pulling slightly to one side or the other. A little at first, but it will get progressively worse rather quickly. Unless you’re racing a speed-bump course your alignment will not go that bad that quickly. You’re losing air in one of your tires. Side note: This is another way to tell if your tires are just low on pressure. If you notice the vehicle is starting to pull to the side a bit, and maybe your gas mileage is declining, check the air pressure in all four tires. If they’re all properly inflated and the car still pulls, get your alignment checked at a shop.
Finally, you’ll hear a new and rather noticeable sound. It sounds similar to rolling over the rumble strips on the side of the road when you’re texting and driving even though you know you shouldn’t be, and usually you’re really good about it, but right now this is really important. That rumble-strip-type sound is you driving on a flat tire.
Pull. Over. Now.
Now you’re thinking, “Great. How am I supposed to change this thing myself? I have the arms of a 12-year-old anemic girl. I’ll just call the tow service.” That’s fine, if you want to spend a ton of money unnecessarily. But I promise if my 40+ mother with bad knees and an extra 75 pounds on her can do it, you can too. I’m here to tell you how you can do it yourself.
First figure out which tire is the problem. Hopefully it will be on the driver’s side, because then you can pull even farther off the road, putting most of the car in the grass but still leaving pavement for the jack. This is especially helpful when you’re on the side of the interstate: the more buffer of space you have between you and the 3000 pound cars going 70mph (with a driver who is more than likely texting and not paying attention, waiting for the rumble strips to let them know when they’re off the road), the safer you’re going to be. If the flat is on the passenger side, then you can’t pull off very much because you need that pavement for the jack, but at least you’ll have your car as a buffer between you and the death machines hurtling by. Sure, your car is more at risk, but you aren’t which is much more important.
Now that you’ve located the problem tire, get out the jack, and leave the spare for now. It is likely going to be in your trunk area behind some little panel, or under the trunk bottom. If you don’t know where your jack and spare tire are, stop reading this right now and go locate it. I’ll wait.
Got it? Good. Better to be looking for it now when you’re not frazzled and in a hurry and possibly getting rained on.
So you have the jack out. Most jacks are some sort of screw type that uses either a separate handle or uses the lug wrench as a lever. It is very important that you are on a level surface before you bother trying to lift the car. Even being on a level surface, you should engage the parking brake. The parking brake will engage the rear brakes using a cable, so if your flat is a rear tire, just make sure you don’t lift the entire back end up.
It is also very important where you place the jack to lift the car. Some cars will have little arrows showing you the proper lifting points; many don’t. Chances are good that the lifting point is going to be what looks like a metal edge protruding from the bottom of the car. Your factory jack will likely also have a small indent or even a large slot where that metal edge is supposed to go. The key is to make sure you don’t have the jack in such a way that it could easily slip off the lifting point, whatever your particular set-up.
So you think you’ve found the proper lifting spot, the jack base is on pavement, and you’re ready to go for it!
Calm down; baby steps. We’ll get there.
Lift the jack to snug it up to the car, and maybe raise the body of the car an inch. Tire should still be on the ground; all you’ve done is lock the jack in place with barely supporting some vehicle weight. While the tire is still on the ground, use the lug wrench to break the lug nuts loose. Don’t take them all the way off! Just break them loose a bit with the car still on the ground. Two reasons: it’s easier this way, and it’s also safer because you won’t be putting a ton of force on the car suspended on the jack.
Now, about those childlike arms of yours. Breaking lug nuts loose can be very difficult. It takes an air impact wrench in the shop, or considerable upper body strength. Since you don’t have either of those,
you can use your body weight. Put the lug wrench in such a position that you can kind of stand on it, with the force of your weight torqueing the wrench to loosen the bolts. Don’t completely stand on it, and don’t lock your knees up there. When the lug nuts break loose, you will quickly drop to the ground. So if both feet are on it, or your knees are locked, or both, then you’re going to be hurting like hell when you hit the ground with both legs locked. Bent knee, one leg, and slowly start adding your weight to the end of the wrench. You may have to bounce a little; some shop guys go nuts with the impact wrench and tighten the shit out of the lug nuts. But be careful about it – many factory lug wrenches are the folding kind, and if you bounce too much in the not-perfectly-perpendicular direction you’re going to be on your ass.
So now that you’ve broken all the lug nuts loose (but have not removed them completely), you can start lifting the car. Do it slowly at first. Bend down and check where the jack is lifting the car often, to make sure you’re not starting to punch a hole in your floorpan. If you’ve chosen the proper lifting point, there should be zero metal deformation. If something is starting to bend with you adding car weight to that point, then spin down the jack and try again with a different point. Once you have a point that doesn’t bend when you try to lift the car, go ahead and lift the car until the flat tire is off the ground.
You’ve already broken the lug nuts loose, so at this point it should be very easy to finish taking the lug nuts all the way off once the wheel is in the air. Pro tip: use one foot or leg to hold the wheel against the mounting hub while you take the lug nuts completely off. This keeps the wheel from swinging out and continuing to add pressure the back side of the lug nuts, which means you’re just spinning nuts off a bolt thread with no load (basically free-wheeling the nuts, it’s much easier this way).
With the lug nuts off and set to the side carefully in a place you won’t accidentally kick them underneath the car (ask me how I know to avoid that) you can now pull the offensive flat tire off the car. It should just come right off, but in case it feels like it’s still stuck on there, give it a few gentle tugs to break it loose. Don’t yank the hell out of it, because your car is now suspended in the air on a narrow base of a jack. Nothing’s wrong; this is normal. It sometimes happens with the heat cycles of brakes and such, but it’s not permanent.
Now you can bother with getting the spare out of its home. Put it on, and hand tighten the lug nuts. Just spin them on; there’s no need for the wrench yet. Pro tip again: use your foot/leg/hand to hold the spare tire/wheel on while you spin the lug nuts on.
With the spare on and the lug nuts spun on but not wrench tight, start lowering the car with the jack, but not all the way. Only lower it enough until the spare tire is touching the ground a bit. Then use the lug wrench to tighten the lug nuts.
There is a proper pattern to this, by the way. Pick one lug nut to start; it doesn’t matter which one. Tighten that one with the wrench a bit, but not completely. Then pick the lug nut opposite your first one. If you have a 5 lug wheel (most are), then imagine drawing a 5 point star without lifting your pencil from the paper like we did in elementary school. Use that same pattern. The reason you do this is to evenly tighten the wheel to the mounting hub. If you completely tighten one and just move on to the next one, the wheel is not going to be mounted evenly and will cause you some problems.
Tighten them as much as you can, little by little going in that star pattern. If the spare tire starts spinning on the pavement from the force you’re applying to the lug wrench, then lower the car another little bit. You only want to lower the car enough for the tire friction to not be overcome by you and the wrench, but not more than that. So you may have to sneak up on that point of balance. Eventually you should be
able to put some of your weight on the lug wrench again to tighten the nuts without having the tire spin. Don’t put all of your weight on it, because you don’t want to break anything. It has to be tight enough that it won’t vibrate off or allow any movement off the wheel hub, but it doesn’t have to hold a space shuttle together. It’s kind of a ‘feel’ thing.
So now you’ve got your spare tire mounted, the jack is no longer supporting any weight of the vehicle, and you’re ready to go. Put the jack back in its place, along with the lug wrench, and throw the flat tire in there too. Congratulations! You’ve now changed your own flat tire and no longer have to call a tow service for something basic.
Oh, wait… the spare tire is flat too?
(P.S. – If your spare tire is also flat, I say drive on it directly to the tire shop. Spare tires and wheels are cheaper than the primary ones. And will still probably be cheaper than a tow service.)