DAVCO 380 Fuel Filter/Water Separator

This is my first blog entry for our ongoing projects in Diesel Fuel Systems & Hydraulics.

This week we removed, disassembled, and inspected a DAVCO 380 fuel filter/water separator from an FLD Freightliner. This particular system does not use a primary/secondary filter, but instead uses a single filter/water separator in the low pressure (suction) side of the transfer pump. Fuel in/fuel out ports are clearly marked, and the “fuel in” fitting is equipped with a spring-loaded check ball valve. It is mounted to the frame with a bracket near the driver's side firewall by two u-bolts and is easily accessible.

Some thoughts on what I learned:

One question asked during class was if this fuel filter/water separator included a heater. As per service information, I learned that these fuel filters come with an optional fuel heater, which uses engine coolant to heat the fuel and a thermal control valve to regulate fuel temperature. When equipped, the filter housing will have coolant in/coolant out ports and electrical connections. Ours did not.

Basic maintenance is straight-forward and simply involves the replacement of the filter element and old seals. A special tool is used to remove and reinstall the top vent cap (which aids in draining) and the filter cover from the housing.

Overall a good introduction to some basic components of the fuel system on a commercial diesel truck. Of course, during this project the lessons of organization, bagging and tagging components, and the use of service information is always reinforced.

I have included a few pictures below.

 

-Erik Miehrig

Filter housing and clear cover. 

 

Spring-loaded check ball valve for "fuel in."