[Rocketfuel]

I noticed a small pool of diesel under the passenger side a couple weeks ago. I checked the fuel bowl lever and all seemed fine. Drove without any issues over the last 2 weeks.

Yesterday the cab had a strong diesel smell. I noticed a ton of diesel under the wheel well on the passenger side, down the side of truck etc. I must have been dumping a good amount when driving.

Checked the fuel line under pedestal and dry. Checked fuel bowl and dry. Checked the drain tube off the fuel bowl and is wet. Not sure if fuel is coming out the drain valve or from somewhere else where the hose sits.

My fuel gauge is usually 55psi and it drops dramatically when I get on it. This morning was running around 48psi and then 20's on flat surfaces. If under load or hill, it drops into the high teens (18-19) psi.

Purchased the fuel bowl replacement parts and will replace the fuel filter tonight.

Is there another location I should be checking?

 

[Oneof6]

I noticed a small pool of diesel under the passenger side a couple weeks ago. I checked the fuel bowl lever and all seemed fine. Drove without any issues over the last 2 weeks.

Yesterday the cab had a strong diesel smell. I noticed a ton of diesel under the wheel well on the passenger side, down the side of truck etc. I must have been dumping a good amount when driving.

Checked the fuel line under pedestal and dry. Checked fuel bowl and dry. Checked the drain tube off the fuel bowl and is wet. Not sure if fuel is coming out the drain valve or from somewhere else where the hose sits.

My fuel gauge is usually 55psi and it drops dramatically when I get on it. This morning was running around 48psi and then 20's on flat surfaces. If under load or hill, it drops into the high teens (18-19) psi.

Purchased the fuel bowl replacement parts and will replace the fuel filter tonight.

Is there another location I should be checking?

Those two are the most likely, if the drain tube is as you write "wet" that's probably it. I would give it the dry paper towel test..... wrap a dry paper towel around the tube end and turn the key on, engine off. The pump will cycle for about 10 seconds. Do that twice. If the paper towel has fuel on it, bad valve seal.
The solution is rebuilding the drain valve (o-rings) or replacing the valve as an assembly. If you rebuild or buy an assembly one can find both at dieselorings.com. Recommend the florosilicon o-rings, the blue o-rings. Rebuild o-rings are less than 10 bucks and an entire valve assy is about 50 bucks.

 

[klhansen]

Another possible leak spot is the fitting going into the back of the passenger side head. It has a rubber ferrule compression fitting there that's a bugger to get at.
But if your drain tube is wet, that's likely the spot. As Oneof6 suggested, a drain valve rebuild or replacement will fix it up.

 

[Maryland dieselnick]

Your passenger side steel fuel line has a leak. It goes through a sheet metal clamp that bolt to the inboard side of the head. Over time, the engine’s vibration wears a hole in it. I’ve been getting them from a vendor on Amazon. Look for the one with the rubber grommet on the tube. If you can’t find it, you can use a strip of sheet rubber like a cut up inner tube. Use it for insulation against the clamp. Use oring lube on rubber sleeves at the nuts. Tighten nuts until the stop and then add about ten pounds.

 

[Rocketfuel]

I installed a new fuel drain valve assembly. Part is Ford F81Z-9A153-AA.

After doing this job, I regret not purchasing the o-ring kit suggested by Oneof6. The other o-rings are likely getting ready to fail based off the pics.

The valve did not have any cracks or signs of damage. Seals were dissolved. There was a ton of yellow sealant/o-ring on the mating surface. I used a wire brush and diesel fuel to clean prior to installing the new valve.

Fuel pressure is back to 55-60 at idle and drops into high 40's when under load.

No leaks and will keep an eye on the other areas mentioned, especially the passenger side fuel line clamp as it will eventually rub a hole.

Appreciate the help and suggestions from everyone.
Cheers!🍻

 

[klhansen]

Don't know how much you paid for the valve, but I bought some bunaN o-rings from the plumbing shop probably 10 years ago when my drain valve started leaking, and they're still in good shape. They cost me about 50c each.

 

[Maryland dieselnick]

The advantage of the blue rings is that they work a little better in super cold temps and hold up longer. The ones that came with your drain will be ok if you got the yellow Teflon coating off of the surfaces first. If your old Orings were dissolved like gum, somebody at some point used some type of alternative fuel. If it was just the yellow Teflon coating left behind, that is normal.
Your pressure drop during acceleration is about normal for a stock set up.