The Stanadyne Water Seperator Exposed

[69oiler]

doesnt sound like you have any air leaks. nice ride by the way.

 

[zigg]

doesnt sound like you have any air leaks. nice ride by the way.

Nope, but fuel leaks sure can become costly. I finally got my 2 leaking injector o-rings to seal, and it's amazing how slowly that fuel gauge drops now...A small leak can make a big difference.

Zigg

 

[FordGuy100]

nice ride by the way.

Thanks .

Maybe I should plug the hole up the hose to stop it from driping. I wonder if the seperator is working right know.

 

[Agnem]

Ah! Back to my original point. Just fix it.

 

[84TD]

Will you add this to the Tech section so it is easy to reference?

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We all know that the factory 6.9 water separator is prone to letting air in the fuel system, and that a common remedy is to either remove it all together, or plug up the drain hose. What nobody has been doing that I am aware of, is repairing it, and it may be as simple as cleaning it.

At the 2007 IDI Weekend in Rising Sun, Indiana, I brought along a disassembled unit to take some of the mystery out of that silver cannister. Follow along with the pictures below to see how it works, and what could be done to get it to seal properly again.

The unit is made so that it doesn't come apart. The "bowl" is pinch seemed onto the head, and the only way to get one apart is to destroy it. However, there is one way, which we shall examine.

First, let's look at our "exploded view" model to see what exactly is in there.

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Inside the unit, there is a plunger, which serves to plug the bottom of the bowl, a rod, which senses the water and turns on the "Water in fuel" light, and the actual filter itself, which is basically nothing more than A SOCK! OK, it's probably a special sock, but it sure looks like something that had been on somebody's foot for a really long time.

Inside the bottom of the bowl is... well, nothing. This is where the sediment builds up, and collects around the rubber stopper. So when you pull the plunger up to drain it, all the sediment falls into the path of the rubber stopper so that when you release the drain, it seats on dirt, instead of a clean metal surface.

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Here is a better view of the 3 main parts, the sock, the plunger, and the rod.

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The good news is, that the one part that does come off on this thing, is the plunger assembly. Here we see my oldest son, Matthias, unscrewing the plunger from the head. The large nut under the pull ring is all that is needed to be loosened.

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Once the threads are disengaged, you can pull the whole plunger assembly out. There is one caviot.

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The "Sock" may try to get caught between the white plastic part you see about half way down the plunger assembly, and the hole that it is trying to pass through. Some determination and dexterital finagery may be required to get this part to clear.

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Once the plunger assembly is free, you can inspect the rubber tip for debris, or defects.

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Now it is just a matter of devising something you can insert in the hole in the top of the filter head, to get down to the bottom of the bowl and clean out the drain area. Perhaps a thin wooden dowel could be used to clean it out, or compressed air, or a vacuum. Armed with the knowledge of how it is made, it may be easier to fix it, then to replace it, and less costly too.

 

[ttman4]

Nope, but fuel leaks sure can become costly. I finally got my 2 leaking injector o-rings to seal, and it's amazing how slowly that fuel gauge drops now...A small leak can make a big difference.

Ditto on that Zigg. When mine kinda drops 2-3 MPG I start looking & smelling for leaks.

Will you add this to the Tech section so it is easy to reference?

Mel,good idea I think too....send'er to the Sticky Tech Section!

 

[Agnem]

That's the plan. Just wanted to let it get hashed out here first, as I will clean it up once everyone has had their say.

 

[Agnem]

OK, so it is moved to the tech articles, and as often happens the embedded pictures get hosed. Sorry about that folks. In the thread it was mentioned that we have no way to test and see if the seperator is working... not true. Just drain the contents into a glass jar, and let it settle out. Any water present will collect in the bottom of the jar. If you don't see ANY water... well... you've got some excellent fuel, or maybe... um... it isn't working?