Refer to maintenance schedules in Group 0 in this manual for recommended fuel filter replacement intervals.
Draining water from fuel filter/water separator housing:
The housing drain valve serves two purposes. One is to partially drain filter housing of excess water. The other is to completely drain housing for fuel filter, drain valve, heater element or water-in-fuel sensor replacement.
The filter housing should be drained whenever water-in-fuel warning lamp remains illuminated. (Note that lamp will be illuminated for approximately two seconds when ignition key is initially placed in ON position for a bulb check)