Mechanos, I owned three prior deseils, two with water separaters plumbed ahead of the fuel filter. These two worked well and never left me with a jelled filter and I drained them only periodically. The 2001, 4x4. 3500 is my fourth desiel, first dodge cummins. It has the filter in a canister housing [fuel] which being a paper product seems to absorb some water leaving little if any to be drained mechanically. The filter doesn't want to give it up!! I'v noticed the absorbed water appears slightly darker in the filter. This seems to be of no consern down to about 6 degrees F. At 0 degrees I expect trouble! My unit has stalled due to jelled filter condition limiting fuel to the pump and upon replacing the filter I found very little water [ 1or 2 beads] in the bottom of the filter housing.Separating water is only a passive function of this system as I have had to change as many as three filters in one week of below zero temperatures after a dose of water at fill up. Yet very little evidence of water in filter housing. I now run Howes fuel conditioner in the winter and carry a spare fuel filter and a 20 oz bottle with fuel in it for topping off when changing the filter. If you drain the entire filter housing or your drain valve sticks open and accidently dumps the whole load [as mine does!] the 20 ouncer saves the day ! LOL STY

 

I use Power Service fuel conditioner/anit-gel additive and I've had no problems at all so far. We've been down in single digits for about a week now with a couple night going below zero.