If you leave it out long enough it will drain the whole tank. The drain is only a purge to let any water that accumulated drain out.

 

AHH, well that makes more sense. So, I assume when you remove the filter housing diesel will continue to trickle out, correct? So no fooling around and get the job done.

 

Mine only drains for a short while and then it quits. It certainly does not keep draining when I remove the HFCM cap. I do wait to change the filters when the fuel tank is below 1/2. I do not know if even that is all that important. Maybe others can help explain the differences.

BTW - this thread was started just to discuss the draining of the water separator. There is a separate one on filter change (even though there are links to the filter change procedures in this thread).

 

I’m no mechanic but it was very simple. Removed the drain plug with a 6mm allen and it drained for about 30 seconds. I only had about a quarter tank of fuel but one would think that you shouldn’t have a continuous flow as it’s just the fuel in the pump and the pumps not running. But again, I’m no mechanic. The whole draining and two filter change only took about 20 minutes to complete. I can’t believe my dealer wanted $325 to do it… <?xml:namespace prefix = o ns = "urn:schemas-microsoft-comfficeffice" /><o></o>

 

Mine too drained until I turned it off.....
it was NOT going to stop and NO WAY there is 2 gallons of water in that little WIF filter

 

I'm changing my FFs this weekend and had read some post here on FTE that a good way to keep from getting the "diesel bath" on 4x4s is both to run the tank down to 1/4-1/2 and to park the truck with the driver's side front wheel on higher ground (jacking should work here too). I'll try it and see...

 

I changed mine 2 weeks ago on my 4x4 and it took exactly 19 seconds from the time I pulled the hex screw until it stopped draining. I had a little over 1/2 tank of fuel. I just got a 10 quart open container and held it up near the frame and did not get a bath. Now I just need to find a better way to get the filter out. I had a 10" extension - too long 6 and 4" and too short and that sucker was on there. This was the first time with this truck so hopefully lubing the O-ring will make next time better.

 

Strange, but my OEM drain plug is steel, not brass. I bought my truck new, so it is not after market. Maybe it is a Ford upgrade for that year.

 

My 06 is brass

 

Maybe it was a mid year change? My '07 is steel too...

 

I just changed my filters today and posted my observations on the upper filter change, in a thread here in the tech section dedicated to that.

On the lower HFCM filter change (I have a 4x4, so it's relative to that model):

My '07 has a steel 6mm hex drain plug. I saw a post from one '06 owner that had the same and another post from an '06 owner that had the brass plug, so my guess is the plug change from brass to steel was a mid '06 model change.

I ran my tank to under 1/2 full on the gauge and then parked it so the front and driver's side was highest. Fuel hitting the frame rail while draining was not a problem with this technique, but I also put a piece of aluminum foil under the HFCM and filter just in case, and it was needed when I pulled the filter as it drips further into the rail area.

Only other thing is to pull the brake line out of the snap-in support so you can get the filter and cap all the way out (just snap it back in after you're all done). All the rest is as others have posted... And it's still a messy job even when you are prepared for it

 

I've change my filters a half dozen times, never noticing the amount of fuel in the tank and usually the flow stops coming out of the HFCM, today it never stopped and I was not prepared for a continuous flow so they didn't get done. The flow was constant but not heavy. The truck was pointed slightly downhill in my driveway. Nearly full tank. Drained about a gallon out. $2.89 wasted.

So does anyone know the real reason why some people drain gallons of fuel and other times it stops? Tank level? Truck needs to be level? Slanted uphill? Warm out? Cold out?

 

I drain my HFCM in the same spot on my driveway every time. When the tank is close to full, it never stops, and when less than half, it stops after about a pint. Just my experience for what it's worth.

 

A pint sounds right. Seems like tank level matters.

 

I have owned my first Diesel truck for a little over a month now. I love it. Unfortunately I have had to replace both batteries last week and then the Water in fuel light has come on. I followed the procedure listed (three times) and every time the wif light comes on around 4 minutes after starting. By the way, should have gone with the rubber gloves! 4X4 caused me to smell of diesel for quite some time! Whats next step? Filters? Manifold? Sensor?