I just finished changing the fuel filter/water separator on my 2015 F250. I have done these before on my 2012 multiple times. I went to the Ford dealer and bought factory Motorcraft filters. Everything went as planned. Replaced the large O-ring that came with it. Hand tightened the housing until it stopped.
The issue I am having is when I prime the fuel filter, i hear it priming and once it stops priming it pours all the fuel out of the water/separator drain. The Yellow petcock is fully seated. It doesnt pour fuel out until I turn the key to the off position. I can hear and feel that it's sucking air from the drain

The O-rings looked like they were in great shape. This is the first fuel filter change on this truck.
It has only 25,000 miles.
It has a full tank of Fuel.

Aaron Brown

 

Have you taken the canister off and inspected the fuel drain closely for defects?

I would take the canister off and see if i could solve the leak on the bench with water or fuel prior to putting it back on the truck.

If you use water to test, make sure you blow out the canister prior to installing back on truck.

 

Did you check to make sure the fittings are connected under the hood?

 

The problem is you "Hand tightened the housing until it stopped". You can't hand tighten the cap and expect it to reach the hard stop. You have to use a wrench/socket to achieve the physical stop.

 

Guys, he said it is pouring fuel from the separator drain - not from under the hood, and not from the canister housing. Obviously, closer inspection is needed on the petcock and o-rings in it - as Larry indicated.

 

Aaron, when you changed out the lower filter, and had the canister off, did you also have the petcock completely unscrewed? To me, it sounds like the O-rings in the petcock became dislodged or unseated when you put it back in....I'd remove the entire canister, and then remove the petcock and examine that again. I cant recall totally, but it seems like there are two O-rings in there. If they are still there, but dislodged, put them back in place and then lube them with a little bit of motor oil.

 

Thank y'all for the help. I figured out there are 2 green o-rings on the yellow petcock and an additional thick black o-ring on the tip of it that sticks inside the valley. It seems like it wasn't lubed up from the factory. If you pull the yellow petcock completely out it will eventually become dislodged but good luck finding it. I definitely got lucky and found the part at the bottom of my oil catch pan.

 

big thumbs up!

 

I've used WIX cap/filter for 6yrs now..no issues. There is no bevel oring, just flat. Now, with price of these darn things, found a different name filter on eBay for 8ea. So, I bought 4.
where I'm going with this is, a member did a measurement on the oring, and posted I, finding them at McMaster Carr..having the same issues as you. If i/someone else finds the thread, mind posting ur up....

 

I had the same problem. Every time the pump stopped, fuel would drain out. Dumped my drain pan and found the missing black washer. Problem solved. Thank you