Preventing and Handling Your Own Emergencies

If your agency does a great job of maintaining your ambulance, count yourself lucky. There are organizations that respect neither the value of their people nor the consequences of sloppy fleet care. Ambulances are complex machines. Even with expert maintenance, they’re made of parts that wear and eventually fail—just like the human body. In this final installment of Ambulance A&P, we’re going to walk you through a good vehicle checklist—and a couple of risky emergency procedures you may need to handle when there’s no one to help you: jump-starting your engine and changing a tire.

Your Vehicle Checklist

Your first job in EMS isn’t to save people’s lives, and it has nothing to do with being a medical genius. It’s to come home safe to your family. That presupposes a realization on the part of you and your agency that you are not an expendable resource. You are valuable. Irreplaceable. Losing you would hurt us all.

But if you don’t thoroughly check your ambulance at the beginning of every shift, you’re goofy. All that scene safety stuff you practice at every skills station in every recert exam is garbage, because you have no assurance of ever reaching your next scene. These are strong words. But somebody needs to say them, because too many of us don’t bother to check our ambulances before we head for Starbucks. If your agency won’t build checkout time into its schedules, find another agency—or come in early and do it on your own time. Or do it at Starbucks. But do it. There, that’s out of the way.

There are two ways to check an ambulance, and you need to do them both in the same order every time. The static check looks at the things you can see without starting the engine. The dynamic check looks at things you can only see with the engine running.

Static Check

Always start a vehicle check the way you approach an unfamiliar scene: from a distance. Even your own ambulance may not be the same vehicle you worked in on your last shift. Look at the thing, and ask yourself if this is an ambulance that could end your life. Is it sitting level on level ground? Are there fluids under it? Is there new body damage?

Conduct a walk-around, which is a lot like a scene assessment. Examine the tires for abnormal or excessive wear. (Do they appear to be inflated normally?) Check your fuel. You should probably start your shift with full tanks. You have no idea what’s ahead of you, and refueling is so easy. (Incidentally, if you ever put gas in a diesel tank or diesel in a gasoline tank, avoid starting the engine and call your fleet staff immediately.)

Check your O2 levels, both in the portables and in the big tank. Do that specifically before you check your fluids, to keep the fluid residues away from your O2 systems. (The combination can cause fires.)

Pop the hood and check the motor oil before anyone starts the engine. (Put the keys in your pocket, so somebody doesn’t start the engine while your hands are under the hood.) When you check any fluid, check it for quality as well as quantity. Motor oil should be amber or brown (brown in a diesel). It should flow on a warm dipstick, and it should feel slippery between your fingertips. Take a good look around the engine compartment and at the visible components under it. Note anything that looks unfamiliar to you, and consider the possibility that someone has worked on the vehicle in your absence.

Most of us check tire pressures about as often as we take patient temperatures—almost never (dumb and dumber). A ton of tire failures are caused by under- and overinflation. Why would you want to risk your life over something so simple?

Dynamic Check

Next, start the engine.

An ambulance needs to be able to start, steer, stop and stay running. Those four S’s are like a patient’s ABCs. Anything you detect that would hamper one of those four functions should prompt you to put yourself out of service immediately. Incidentally, there was a time when the dashboard instrumentation in an ambulance was unreliable, but you can generally trust the modern stuff. Just like a patient, your ambulance has a way of telling you how it’s doing. Teach yourself to watch those gauges routinely, the way you taught yourself to watch a patient’s face.

Check your transmission fluid with the engine running. It is essentially lightweight machine oil, so it should behave the same way on a dipstick as motor oil. But it should be pink. If it’s brown or smells burned, that’s not an emergency, but you should mention it to your fleet folks. Steering fluid gets burned too, although fresh steering fluid can be a different color than transmission fluid—clear or maybe yellow, depending on the brand. Coolant also comes in a variety of colors.

Beware of the presence of bubbles or voids in your lubricants as they appear on the dipstick, especially if the engine is hot. Both findings can indicate the presence of water or other impurities, and they’re always important enough to mention to the fleet staff as soon as you can. Active bubbling in the coolant reservoir is also important, and can mean your motor has a leaky head gasket or a cracked head. (That can also make the motor run hot.)

There’s no need to open the coolant reservoir or the radiator, both of which can be dangerous even at normal engine temperatures. The cooling system is pressurized to raise the boiling point of the coolant. You release that pressure when you open the system, and the coolant can expand very suddenly—spraying your face, neck, arms and upper torso. Normal coolant temperatures exceed 230–240ºF, which can produce significant burns.

Likewise, you should avoid opening the brake fluid reservoir. Brake fluid can absorb moisture from the atmosphere, and that moisture will attack the hydraulic components of your brake system. If you’re low on brake fluid, there’s a problem somewhere. The experts need to know about it, pronto. You won’t make it better by adding fluid.

If you notice that your ambulance has more than two inoperative lamps of any kind, start watching your system voltage. It can change overnight—for instance, if somebody accidentally turns off the batteries with the engine running. You know better than that, right? It can fry the voltage regulator in your alternator, allowing the thing to generate something like 18 volts instead of 14. Eventually, that can destroy your batteries and burn out lots of other stuff.

Your brake lights and backing lights are important. But you can’t check them by yourself unless there’s a reflective surface behind you. Even then, you’re not likely to see both sides. Whatever you do, don’t just assume they work. Check them (and your directionals) faithfully at the beginning of every shift.

One or more reinforced rubber drive belts transfer energy from the motor’s crankshaft pulley to a number of appliances on the front of the motor: the AC compressor, the alternator, the water pump, the vacuum pump and the power steering pump. Even with your AC on and running all of your emergency lights, the alternator should be able to maintain a system voltage of about 13.5 volts. If it doesn’t, you have a problem. (Who ya’ gonna call? Right, your friends at the shop.)

With the engine still running, stand to the side of the hood and watch the movement of the belts. They should not chatter, squeal or wobble, and you should see no fraying.

Listen to the motor, and get used to the sound of it idling. Eventually, you will get to detect abnormal sounds in this machine that earns you a living. But even in a new ambulance, other than the normal clatter of a diesel, you should not hear a lot of engine noise at idle. The RPM should be constant, and there should be no knocking, squeaking or hissing.

Jump-Starting Your Vehicle

We’ve all made the mistake of leaving too much stuff on for too long without the engine running. When that happens, one way to get your engine started again is a jump-start from another running vehicle. Jump-starting is not a substitute for weak batteries or a poor maintenance system. If your batteries are prone to failures, you have a problem. Eventually, it could result in the loss of someone’s life. If that happens and you have failed to act, you will personally share the blame.

Jump-starting can be a hazardous procedure if you don’t know what you’re doing—especially if one or both of the batteries you’re connecting have been working hard (and are therefore venting hydrogen). Before resorting to jumper cables, first shut off everything on the unit that has failed. Then look for a loose battery cable end. The battery cable ends should be attached tightly enough so you can’t move them with your hands. If one moves, tighten it with your hand as much as you can by twisting it left and right and pushing downward on it. You may be able to start the engine at this point. If you get the engine started, let it idle and make sure the alternator is charging the batteries at 13–14.5 volts. Then drive the unit back to your station and attach it to a good battery charger for several hours.

If the unit won’t start, park a running vehicle within battery-to-battery cable reach. Unroll and untangle a pair of good battery cables. Good means two things: All four clamps should have strong enough springs to leave several marks on a lead battery post, and each clamp should be firmly attached to a fine-stranded, highly flexible copper conductor, at least four gauge (No. 4 American Wire Gauge) or bigger. (No. 4 wire is about 3/8" in diameter, not counting the insulation.) A good pair of jumper cables should be about 10´ long.

One person acting alone should make all of the connections, as follows:

• Leave the black cable ends for last.
• Connect one red cable end to the positive (+) terminal of the battery in either vehicle. (Positive battery conductors and their connectors are usually color-coded red.)
• Connect the other red cable end to the positive (+) terminal of the battery in the other vehicle.
• Connect one black jumper cable clamp to the negative (-) battery terminal of the good battery. (Negative battery conductors and their connectors are usually color-coded black.)
• Connect the other black jumper cable clamp to the frame metal of the vehicle with the dead battery. It will probably arc when you attach it. For that reason, do not attach it directly to the negative terminal of the battery. In fact, this last connection should be as far away as possible from the battery and the fuel system.
• Wait for about a minute, then start the vehicle that has the dead battery.
• Wait for about a minute, then remove the cable end from the frame of the vehicle that had the dead battery.
• Remove the rest of the cable ends in any order, and stow the jumper cables.
• Check the system voltage of the vehicle that had the dead battery. It should read between 13–14.5 volts with its own engine running. If not, take the vehicle out of service.
• Either way, let the fleet staff know what happened. They may want to check the electrical system.
• Charge the batteries for a few hours with a good battery charger.

Changing a Tire

The jack and tire tools that came with your ambulance are suitable for emergency wheel changes, and so are you. But neither you nor your tools should be changing a tire on an emergency vehicle in anything but an emergency situation, when a mechanic is unavailable. If you have a blowout and can get the vehicle to a mechanic within a couple of miles, it’s better to sacrifice the tire and drive on it than to try changing it yourself in the roadway. If you have a blowout on the freeway or in an area where visibility is poor, get the vehicle away from traffic any way you can—especially if you have a patient aboard. If you have a blowout and you’re not committed to a call, contact your communications center and ask them to consult the fleet staff for input. Then decide whether to change it yourself or not.

You can change a tire safely if you have to. You need to do that out of traffic, and you must do it on solid, level ground. But no matter how mechanically smart you are, you’re not going to change anything at all if you don’t have a properly inflated spare, a jack and handle, and a properly sized lug wrench. Of course, being a professional, you checked that stuff. So you know you have it, and you know where it is.

There are some tricks to changing a tire, especially on a commercial vehicle. First, don’t apply the jack until after you loosen the lug nuts (just a tad; it’s called “cracking” them). Second, maximize your safety by minimizing the amount of time a jack is supporting the vehicle. And third, when you loosen the lug nuts, use your weight as a resource. Here’s how:

• Use the pry bar (it looks like a big screwdriver) to remove the wheel cover, if any. Simply insert the screwdriver-looking end between the edge of the wheel and the edge of the wheel cover, and pry the wheel cover off. The wheel cover is held in place by little clamps, and it will come off easily. Or…
• If the wheel cover is one of those stainless steel vanity covers that fits snugly over the whole wheel, it’s probably held in place by the lug nuts. You will need to remove them first, as follows:
• Slip the barrel of the lug wrench onto a lug nut, and slip the handle through a hole in the barrel. Rotate the barrel so it firmly engages the lug nut with the handle just about parallel to the ground and fully extended (shaped like an “L” with the barrel, not like a “T”). Use your weight to push downward on the end of the handle, with the goal of unscrewing the lug nut about one full turn. You may need to bounce on it initially to get it to turn; then it should get easier in a hurry.
• Repeat this procedure until all of the lug nuts have been “cracked.” Do not loosen them further until the vehicle’s weight is resting on the jack.
• Set the brakes, and set the transmission in Park. Insert the jack under the frame of the vehicle, as close to the wheel as possible. Raise the vehicle until the tire clears the ground by about half an inch, and no farther.
• Remove the lug nuts one at a time, and place them inside the inverted wheel cover or in a pile where you can reach them easily.
• Slide the wheel off its bolts, lay it on the ground, and slide the spare wheel onto the bolts as soon as possible.
• Thread the lug nuts back onto their bolts, one at a time, and hand-tighten them. Snug them up with the lug wrench, but do not attempt to tighten them completely.
• Lower the vehicle so its weight rests fully on the spare, and collapse the jack again so it can be stored normally.
• Tighten the lug nuts in pairs, beginning with any nut and then countering with the nut on the opposite side of the wheel, until all of the nuts have been tightened as firmly as you can make them. Use your weight to tighten them down, like you used it to crack them in the first place.
• Stow the flat tire and the tools, and either reapply the wheel cover or stow it as well. You can hammer it into place with your hand, but first be sure to line up the valve stem with its location in the wheel cover. If you don’t, it may not go into place.

Conclusion

This has been the last in a series of five articles intended to give you the basic knowledge you need to understand an emergency vehicle. It won’t make you a mechanic. But you’re smart enough to understand the anatomy and physiology of the human body, so we think you’re surely smart enough to understand what you hear, smell, see and feel about the way your vehicle behaves. You owe that kind of understanding to yourself and your family, your patients and your colleagues. Don’t you agree?

The authors would like to acknowledge EMT Shaun Howard and certified Emergency Vehicle Technicians Chris Ferwerda and Jim Gergen, without whose help and hard work this article would not have been possible. (Chris and Jim worked a LOT harder than Shaun, though.)