Dirt and dust can reduce engine life by 50% if they get into your fuel system. Even
tiny amounts can grow into damaging and potentially costly obstructions. In fact,
such contaminants account for more than 85% of all fuel system failures. And newer
engines’ high pressure fuel injectors are even more susceptible. The tiniest of particles
can grow into damaging and potentially costly obstructions. Here are some tips on what
to look for and how to maintain your fuel system.
Areas of Potential Damage
Areas where there are quick, sliding movements are particularly vulnerable to dirt and
dust, which interfere with motion. Prime places for such obstructions are inner and
outer valves, nozzle needs and seats, and pistons, but they’re nothing compared to the
harm that can be done to injector barrels and plungers and control valves.
These areas should be inspected and cleaned regularly:
Interface between Injector Barrel and Plunger
2.5 microns is the amount of fluid needed to maintain the smooth and continuous
operation of an injector barrel and plunger. Dust or dirt in this area can seriously
interfere with the machine’s mobility.
Contaminants can wear away control valve seals, greatly reducing fuel pressure and
engine power, straining the machine and wasting fuel.
How to Stop Dirt and Dust from Entering the Fuel Line
Always replace the nozzle back into the pump when you refuel. Letting it touch the
ground will dirty the head, contaminating your machine.
Construction can be dusty work. Keep vent tube and fuel caps tightly sealed to prevent
dust from entering the fuel system.
You don’t want your engine exposed to too much dust, so be diligent about
maintenance—filter changes, refueling, and engine repairs—and complete them
indoors, if possible. If not, only open service hatches when necessary and close
them when the job is complete. This approach will greatly reduce risk of fuel system
When Changing Filters
Change filters regularly. Manufacturers have suggested intervals and filter types that
should be followed. If a filter is clogged, it can’t stop any more dirt from entering into
your engine. Always follow the operator manual’s instructions when changing all filters,
both main and prefuel. Be sure to look for possible leaks that may let particles through.
Tips for Changing Filters
Avoid introducing dust into the system by not filling the filter element with fuel when
changing the main filter. Use the priming pump to fill the new filter. Also, check to make
sure O-rings fit properly, as a poor seal can lead to fuel system contamination.
New prefuel filters should be inspected before installation. Be sure to check that the
cap is attached to the new filter before pouring fuel into the cartridge. (Do not use the
center hole.) Once the cartridge is full, remove the cap and discard it. Next, apply a thin
layer of engine oil to the cartridge’s packing surface before installing the prefuel filter
carriage into the proper filter holder. Insert until the cartridge’s packing surface contacts
the sealing surface of the filter holder, then turn to tighten the filter cartridge.
How to Prevent Water from Entering the Fuel Line
Condensation often forms on machines at night, when the temperature drops; water
may enter the fuel tank. You can stop this condensation from forming by filling the tank
up at the end of the day. Then, the next morning, before you begin operation, drain
water and sediment that has accumulated at the bottom of the tank. Similar procedures
for draining should also be completed about ten minutes after each refuel.