I want to service my E350 7.3 '93 myself. One point not very well explained either in the manual nor Haynes was draining of water from the filter/waterseparator.

I have understood what to do now, but my first try ended up with loosening the bottom of the filtermodule itself. (I did not remove the filter). Just some small amounts of fluid ran out.

Do I have a problem if SOME dirt followed the bottom back to the filter? (- I don't think it did, but it is not very spacy or very clean in there.) I believe this bottom is a part of the "dirty" side of the filter?!

I noticed three items in this part. One in the centre (which I now understand is the draining) and two on the diagonale. One of these two was connected to a wire. I guess this is the water sensor.

How does this work?
What is the other item on the diagonale?
Can anybody help me with an illustration or explanation of this construction?
Do I have to do a new, proper drain of the filter?

After I mounted the bottom back the engine fired and stopped a second later. Then I had to crank it for perhaps 30 seconds (but in intervals) before it started again. Some more seconds later the engine run normal. All this was expected.

What I didn't expect was that nearly all power was gone, - The wan hardly accelerated at all. Still no bad sound or smoke. After some miles everything went back to normal.

Is this behaviour to expect?

Thanks for your kind help.
Torstein

 

The third item on the filter base is a Schrader valve (spring-loaded vent similar to a tire stem). It's completely unnecessary, but when the brass drain valve is wide open (pressed flush against the base) it presses the center pin of the Schrader valve, possibly to aid in draining water. I avoid having to reprime the fuel system by draining the water bowl with the engine idling, but COLD, which prevents air from entering the system. NOTE: I would not recommend this to anybody but an experienced mechanic. One must be EXTREMELY CAREFUL (!!) to avoid contact with the belts or fan when doing this, and open the drain valve ONLY A TINY BIT, because the filter will be under slight pressure. Hold a thick rag under the base - this will eject lots of fuel, and any water that might be present, without allowing air or dirt to enter. This is NOT recommended by Ford or anybody at this forum because of the potential for fire and/or injury, I'm just saying it works for me every time.

Pick up a copy of Haynes Diesel Techbook No. 10330 - it covers the IDI fuel system very well.

 

Thanks curmudgeon!

- Is it so to understand that the brass drain valve is pressed into the filter to open it up and let the water out, and then some mechanism opens the Schrader valve for air?

Then the bowl I faulty removed normally is dry? But it was not?
And how does the water sensor know that it is water in the filter???

????
Torstein

(I have not yet been able to study the outside of the filter. I guess I find some answer there, but it should not be neccesary to switch filter by now)

 

Since water is heavier than fuel, it collects on the bottom of the bowl. there is an insulated probe about 40mm above the bottom. The water conducts electricity, the fuel does not. When about 200ml (6oz.) of water has accumulated, it touches the probe and lights the "Water In Fuel" light. Simple, yes?

The Schrader valve is not needed to drain the water bowl. It has no other purpose, in my view, than to cause air leaks and earn money for anger management clinics.

 

- So the bowl stays with diesel (or perhaps water) in it. Then I guess there is a valve in the bottom of the filter element itself?

Thanks
Torstein

 

I like to do thing properly!

So I ended up with trying to open the drain valve again. It really had stucked! I dismounted the filtre with everything, and had to use a plier to to open the valve. After removing the bowl I of course understand the construction. I thought the filter was closed in the bottom, with just some sort of opening for the drain valve (ridiculous when you have seen the construction. Sorry for my stupid questions).

BUT: WHAT DO YOU DO SO THE DRAIN VALVE NOT STICKS AGAIN??

 

You should never need to tighten the brass drain valve more than finger-tight. It is the OPPOSITE of most threaded fasteners - when the knurled thumbwheel is backed out away from the bowl, the valve is closed. Make sure you replace the tiny gasket under the cap nut every year or with every new filter. If you are using pliers to open and close the valve, you will soon be on the side of the road holding a cardboard sign when it breaks off and drains your fuel header uncontrollably. Been there, done that. It sucks.

There are no stupid questions on this forum except the ones you don't ask. We all have to learn somewhere.

 

So now I suppose the case is to its end:

The old filter was absolutely due for a replacement I saw when it was dismounted. So I inserted a new filter (from ACDelco), took a close look at the drain valve and found my problem. The brass holder for the gasket was so high compared with the gasket itself so when the drain valve closed, the brim of it seized into the bowl.

I tool a file and grinded the brim down a bit. It seems to work well.

 

On the trucks the schrader is on the top of the filter head and points to the driver's side of the engine. It can be used to bleed air out of the filter when restarting and to empty the filter when the drain is open (place a hose on the drain pipe leading down the block to a soda bottle to catch the fuel). When replacing the filter fill it up with fuel additive to help remove the air and to give the pump and injectors a good lubing. If using the schrader to bleed the air place a rag around it because the fuel is under pressure. I realy don't need to bleed mine. It stumbles for a bit then smooths out quickly.

 

The shoulder on the underside of the cap nut is to prevent the gasket from distorting from over-compression. Yours was seized into the bowl because nobody replaced the gasket every year or two the way they should have. Then they began using pliers to close the valve when it started leaking. If you filed off the shoulder, the gasket will always be over-compressed and either leak or fail prematurely. You now need to buy a new cap nut because you ruined the old one, and a new bowl because the gasket seat area has been damaged by the rim of the cap nut - about $30.00 worth of parts, all because nobody wanted to replace a $0.50 gasket.