Not everyone sees their tools in the same way. For some, anything from an air compressor to a socket wrench is a consumable, meant to be used hard until it breaks and has to be replaced.

Other people think of tools as almost extensions of themselves. They’re objects to be protected, cherished, and eventually passed on to the next generation.

Most of us take a pragmatic attitude somewhere between these two extremes.

We also know that giving your tools at least minimal care and attention makes them last longer and work better. In the long run, it’s most definitely better to rinse the dirt off your shovel before putting it away, put a drop of oil on any moving parts every once in a while, and sharpen or change worn-down blades.

When it comes to a lathe or compressor costing several hundred dollars, doing what’s necessary is also one of the most painless ways to save a great deal of money.

Just as importantly, you as well as any visitors will notice a huge difference between walking into an organized, (relatively) clean workshop and one that looks like a war zone. Picking up a tool you know has been taken care of can be very reassuring, and that will help you carry over the same diligence to the rest of your work.

Before You Even Turn it On: R-T-F-M

RTFM, of course, stands for “read the fine manual”, although some people in an emotional moment may have used a word other than “fine”.

As you can see in our overview of the 14 best air compressors, there are huge differences between the various compressors. Some require regular oil changes while others are designed to run dry. A few have batteries that will need to be replaced long before the motor starts to wear out. Some have fairly elaborate preventative maintenance schedules while others aren’t supposed to be serviced by anyone but a trained technician.

The only way to learn about the peculiarities of your model is to actually scan through the manufacturer’s documentation.

Thanks to the American legal system, you’ll also have to endure pearls of wisdom like those telling you not to operate machinery while drunk or lift objects that are too heavy for you, but that unfortunately comes with being part of modern society. Especially if you have a fairly extensive collection of power tools, it’s a good idea to jot down any important points in a notebook, including model/component numbers and spare part ordering information. This is also a good place to sketch out a maintenance schedule for everything you own.

Everyday Habits that Will Make your Air Compressor Last

If you only use your air compressor briefly every now and again, it becomes far too easy to forget when you last did the things to which you should pay attention. The only solution to this is to do the following, which should take no more than two minutes or so, every time you put the machine away:

• Check the oil. We’re assuming here that you’re not using an oil-free compressor. Running any other kind without adequate lubrication, even for a short while, will do major damage and probably void your warranty. Oil levels have to be checked while the machine is on a level surface.
  TIP: If you’re always spilling oil because of the “glug, glug” thing a full jug does, try turning it onto its side. It really is that simple.
• Do a quick visual check. Make a habit of noticing things like oil leaks and physical dings on the tank. In particular, you’ll want to keep an eye on the air hoses you use. These are usually the most vulnerable parts as well as the cheapest to replace. Bear in mind that a worn one can easily turn into a pneumatic whip if it’s damaged further, or at least cause your pressure to drop significantly at the tool end.
• Listen for hisses. These may be difficult to detect in a noisy environment, but whether coming from the hose, its connectors, or the air compressor itself, air escaping doesn’t indicate anything good. At a minimum, the motor will have to work harder than it should.
• Drain and depressurize the tank when you’re done. Even if your compressor has an air dryer, you can count on some condensation forming inside. Over time, this will corrode valves and weaken the tank walls, which is really the last thing you want in something that holds 120 p.s.i. The bleed valve can be found on the underside of the tank and usually requires a set of pliers to open.
• Don’t overstrain your machine. Every compressor has a maximum duty cycle, meaning the ratio of time the motor runs between being allowed to cool off. If you’re regularly exceeding this, you really need a more powerful model.
• Don’t ignore weird behavior. If your compressor starts to make a funny noise, vibrates excessively, or takes longer than usual to charge, something is almost certainly wrong. These kinds of problems rarely resolve themselves, instead becoming worse until you have to trash the whole machine as an unfixable mess.

Spring-Cleaning Your Compressor

For everything there is a season, and when it comes to air compressors, you should take a closer look at yours every three to six months, depending on how heavily you use it.

Proper maintenance intervals are actually specified in terms of hours of operation; if you use your machine every day, the figures given in the manual will provide a better guide than calender dates. If, on the other hand, you don’t turn it on all that often, it might be difficult to guess when you’ve reached this limit. Pencilling an oil change into your calender every three months will keep you from forgetting and allowing the inner workings to gum up.

BSE9619 / CC BY-SA

Changing the Oil

Replacing the lubricant is the most labor-intensive maintenance task many air compressors require, as well as the one that contributes most to extending the machine’s working life.

Just like your car, it’s best to let the motor run for a few minutes to heat up the oil. Make sure that your air compressor is on a level surface – all of the used, dirty oil will not drain out otherwise. But remember that one function oil fulfills is to carry excess heat away from the engine’s working parts. The oil will be hot, as will everything it touches, so be careful.

Simply place an appropriate container underneath the drain plug, remove that along with the fill cap, and allow gravity to empty the crankcase.

Once the flow has stopped, refill the machine with the indicated amount of fresh oil. Again like with a car’s engine, it’s best to run it briefly to let the oil get everywhere it’s supposed to before checking the level again. The correct amount is usually around the midpoint of the gauge.

Also, please dispose of waste oil responsibly. Every carelessly dumped gallon can contaminate as many as a million gallons of groundwater.

Which Oil to Use?

The fount of all wisdom, also known as the owner’s manual, will generally tell you exactly which types of oil are compatible with your compressor’s motor. Trying a cheaper variety, or some random quart left over from somewhere, is usually a mistake. All machines are designed with a particular level of lubrication in mind; using anything else will cause it to run less well and long.

Most compressors use a relatively light 20- or 30-weight oil. It’s also important to make sure that you pick up a “non-detergent” blend – if it doesn’t specify on the bottle, it’s probably not what you should use. Most lubricating oils are intended to clean internal combustion engines as they run, but the chemicals that accomplish this tend to accumulate in air compressors, lowering efficiency.

The main choice you have with regard to oil type is between petroleum-based and synthetic products.

Synthetics cost more, last longer, work better at both high and low temperatures, and allow the motor to run smoothly without generating excess heat.

For most DIY enthusiasts, however, the cheaper kind refined from crude oil will work perfectly well unless they place extraordinary demands on their compressor.

PS. Smaller gasoline-powered air compressors are not very common, but if you happen to have one, you might have to use different types of oil for the motor and pump.

Checking the Air Filter

All the airborne dust and lint that seemingly comes from nowhere has to go someplace, and the air intake on your air compressor seems to be a favorite destination. When you see debris accumulating on the grille, blow it off with the air hose: using a cloth or paintbrush will tend to force dirt further into the vent.

Most air compressors are equipped with an air filter to prevent these small particles from causing damage to the pump and whatever tools it powers.

To get to this, you will normally just twist off the cover and pull it out. Shapes and colors may vary, but it will probably look something like this:

A vacuum cleaner or compressed air can be used to remove visible gunk, allowing air to flow more freely and reducing the load on the motor. All air filters have a service life, though; eventually, smaller particles you can’t easily get out will start to clog it, and replacing your filter becomes the only option.

Looking Under the Hood

Although taking a moment to inspect the exterior of your air compressor every time you use it allows you to spot many common problems, taking off a few cover plates when you’re doing routine upkeep can save you some trouble down the line.

Not all smaller compressors use drive belts, but yours probably has one or two. Check that they’re still tight and in good condition – if you can see a crack, it’s certain to fail at the most inconvenient moment.

Other things to watch out for are signs of corrosion, oil leaks, and loose electrical or air connections.

Since all compressors produce some vibration, it can’t hurt to make sure all bolts and screws are still tightly fastened.

Even if you can’t be bothered with all that, you should check that the pressure relief valve works. The pressure sensor that’s supposed to shut off the pump does sometimes fail, and it’s certainly preferable to hear a hiss instead of a boom when that happens.

A Stitch in Time

Many people simply hate doing maintenance. It doesn’t feel like real work; instead of accomplishing something tangible you’re just ensuring that bad things don’t happen.

It’s also the last thing most of us are in the mood for at the end of a long day, making it all too tempting to put it off until some mythical “tomorrow” that never seems to come around.

Unfortunately, this attitude extracts its toll in both money and frustration. It’s naive to expect that your power tools will simply keep performing at 100% without any effort on your part. Air compressors are pretty hassle-free machines; all they really ask from you is perhaps half an hour of your attention per year.

No matter how busy you are, you can certainly find that amount of time somewhere to keep your air compressor running safe and smoothly.