With a tsunami of used military vehicles returning to the U.S., diesel-powered motors are riding on a new wave of popularity and opportunity. So, if you work in law enforcement, public safety, disaster management, or any number of related fields, it’s a good bet that you’ll find yourself being called on to perform some basic maintenance procedures on a diesel engine in the near future. (Happily, this will not include electrical system tune-ups, because diesels don’t have parts like spark plugs.) Here are a few basics to remember.
Checking on Gaskets. You’ll have to keep an eye on the status of diesel engine gaskets, because they are subject to a lot of vibrational stress. To prevent leaks, tighten the mounting bolts on a regular basis. And when dealing with a leaky gasket, try to replace the gaskets as a set. If one is leaking, the others won’t be far behind.
Changing an Air Filter. While the task of replacing an air filter (or filters) in a diesel engine is pretty much the same as doing so in a gasoline one, there are a couple of differences to keep in mind. First, the diesel version will be located in the cold-air collector box. As auto-repair experts constantly note, the most important difference in diesel air-filter replacement is that you must shut down the engine while you are doing the job. Diesel engines have powerful air intakes, so just about anything loose nearby can get sucked into the engine at this point if it is not turned off.
Changing the Fuel Filters. There are usually two fuel filters in today’s heavy-duty diesel engines. The primary filter is located between the fuel tank and the engine. The secondary filter, which helps clean the diesel fuel before reaching the fuel injectors, is located nearer the engine. Replacing them is similar to changing an oil filter on gasoline-powered vehicles. Consult the owner’s manual before you begin.
Bleeding and Priming the Fuel System. Before changing the fuel filters, remember to bleed any air bubbles out of the fuel line through the air-bleed screw and prime the fuel system, preferably using the manual primer pump. You need to keep pumping the primer handle until the air hissing through the air-bleed screw stops.
Draining the Water Separator. Many diesels have a water separator, which helps purge diesel fuel of any condensated water mixed in with it (a common condition). It’s usually located near the primary fuel filter and can be manually drained by opening a petcock valve to the separator’s collection chamber. Keeping the fuel tank level at “full” will also help prevent water condensation.
Getting a Jump on Winter. In very cold conditions, diesel engines will tend to perform sluggishly. So you might want to consider installing an electric heater to the cylinder block, for starters. Or you can install a heating element in series with the water hose. In a pinch, you can even spray a little starting fluid in the combustion chamber.
Remember, the performance of a high-quality diesel engine is only as good as the maintenance it receives on a routine basis – and that means the job that you do.
Please contact one of our representatives to learn more about the intricacies of military-grade diesel engine systems.