My "Drain Moisture Separator" light came on last week and I pulled over to drain it only nothing came out. It has worked in the past but dry as a bone now. Anyone else ever have problems with the moisture drain?

 

i had to rebuild mine. the valve gets clogged and requires cleaning. not sure if thats what is happening to yours but that's what i had to do to mine...

 

What he said. But I will say don't neglect it. These fuel systems can be finicky and EXPENSIVE to repair.

 

Mine did that on a 900 mile trip I took last year. It would happen every couple of hours and every time I tried to drain it nothin would come out. I called my ford tech and they told me to clean out my sensor with electrical cleaner. Works like a charm now.

 

Thanks, can the drain valve be removed from the filter assembly or does it all come out together?

 

Where is the sensor plug? I'm sure I can find it but it helps to have an idea first.

 

Laying under the truck look up above the separator and towards the engine side of it. It's only about 6 inches away.

 

If you search for this problem there are several write ups, with pictures, about how to remove the cover from the water separator, clean it out and replace the sensor. I bought my truck used and had this problem shortly after I got it. I think it took me about 20 minutes but I have a 2WD truck and I don't know how tight it might be in the area with a 4WD truck. I also shocked the fuel tank, after cleaning the separator, to be sure I didn't have a microbe contamination. And I always change my fuel filters with every other oil change. I honestly think it was due to previous owner not bothering to change the fuel filter in the lift pump often enough. Lazy.

 

Make a habit of draining it every 2-4 weeks. I drain mine every other Monday.

If you bought a used truck that had a plugged hfcm drain that's a very good sign that the previous owner neglected it. Checking to make sure clean fuel flows freely from the hfcm is one of the first things you should check for when buying a used 6.4.

With the limited capacity of the water separator you also don't want to wait for that light to come on... Usually once that light pops up water has already found its way into the hpfp and injectors.

 

When i bought my truck, the valve was clogged. I was concerned. Cleaned it. Been draining it every other tank and no water ever comes out. What does that mean?

 

It means you likely have good source for diesel!

I have almost never had any water come out of the drain valve. But the last time I changed the filter, there was a lot of water in the filter.