Secondary Fuel Filters

Q - I’ve heard that fuel filters with water traps are extremely important for late model diesel engines and was wondering if this is also the case for older diesel engines too. Also, is there any negative side effects from installing an second filter?

A - Pretty much all the Diesels we will know of in the 4WD scene have water traps. To save room and to keep all maintenance in one area for the fuel system, most modern fuel filter system water traps are integrated into the fuel filter. Some older Diesels (Landcruiser 60 series 2H Diesel) had a separate water trap. In the end water traps are a standard part of fuel filter systems. Modern fuel systems return large volumes of fuel back to the tank for cooling the injection system and so installing a 2nd main filter could be restrictive. If you are going to add a 2nd filter then make sure its a “Pre-filter” size element (usually 30 Micron).