Just start using long unsued fuel tank?

[Shadetreemechanic]

There is an oring inside each of those clip fittings. The oring is in the line, not the selector valve. Once the diesel stops pouring all over your face they are easy to get out and back in with a dental pic.
Use a little grease or Vaseline on them to help the new ones slide over the FSV barbs.

 

[Cubey]

There is an oring inside each of those clip fittings. The oring is in the line, not the selector valve. Once the diesel stops pouring all over your face they are easy to get out and back in with a dental pic.
Use a little grease or Vaseline on them to help the new ones slide over the FSV barbs.

There are no clip fittings on these valves. It's a bare hose barb for the hose and a clamp.

Just like this gas version.

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Another example, with factory clamps:

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I suppose it could be leaking from a hose end, being old, fairly rotten hoses. I will pick up some new Gates hose from O'Reilly and try replacing that first. It needs it, regardless.

 

[nj_m715]

I didn't shop for best prices, I just provided examples of possible solutions. I figured anyone interested could take it from there.
here's one a lot cheaper
https://www.amazon.com/GROCO-FUEL-VALVE-PORT-FV65038/dp/B00YMZ3YZM
here's one even cheaper
https://www.discountmarinesupplies.com/Fuel_Valves-Groco_FV65038_6_Port_Fuel_Valve.html
a ford valve is 70-80$ anyway so 120$ is in the ball park or use 2 valves to get away real cheap - just dont return to the wrong tank and over flow it.
amazon has next day shipping and local drop boxes
west marine and other local stores carry 3 way valves
https://www.westmarine.com/fuel-line-valves

convert to a single tank system, use the smaller tank and a cheap fuel pump on a toggle switch to refuel the main tank for a cheap simple fix. it wouldn't require crawling under the truck and would have less points of failure/leaks just dont forget to turn off the transfer pump. I had an old jeep set up like that. had an under seat tank and a rear tank

I'm planing to use 2 pumps for redundancy when I get around to converting to e-pumps I just need a 3 way to switch the return lines.

 

[lsaami]

And that's highway. City is about 7.5

Wowza. I know mine is only 21 feet, but towing a 18ft trailer with 6 four wheelers on it I get 10mpg. The previous owner said he’d get 14-15 empty highway.

 

[Cubey]

Wowza. I know mine is only 21 feet, but towing a 18ft trailer with 6 four wheelers on it I get 10mpg. The previous owner said he’d get 14-15 empty highway.

What trans and rear end? Mine has a monstrous cabover too.

 

[Cubey]

I didn't shop for best prices, I just provided examples of possible solutions. I figured anyone interested could take it from there.
here's one a lot cheaper
https://www.amazon.com/GROCO-FUEL-VALVE-PORT-FV65038/dp/B00YMZ3YZM
here's one even cheaper
https://www.discountmarinesupplies.com/Fuel_Valves-Groco_FV65038_6_Port_Fuel_Valve.html
a ford valve is 70-80$ anyway so 120$ is in the ball park or use 2 valves to get away real cheap - just dont return to the wrong tank and over flow it.
amazon has next day shipping and local drop boxes
west marine and other local stores carry 3 way valves
https://www.westmarine.com/fuel-line-valves

convert to a single tank system, use the smaller tank and a cheap fuel pump on a toggle switch to refuel the main tank for a cheap simple fix. it wouldn't require crawling under the truck and would have less points of failure/leaks just dont forget to turn off the transfer pump. I had an old jeep set up like that. had an under seat tank and a rear tank

I'm planing to use 2 pumps for redundancy when I get around to converting to e-pumps I just need a 3 way to switch the return lines.

Where would you feed the fuel into the primary tank, teed into the return line?

Ideally, I'd rather have it fixed like its supposed to be, with an electric valve.

I will try hose replacement first since they are old, if not original.

Failing that, I'll use the 22gal rear tank, bypassing the FSV, until I want to deal with it futher.

If it was the valve, you would think it would always leak bad. There is a minor leak when set to front but I'm pretty sure that's from a hose far from the FSV.

 

[nj_m715]

in the past I tee-ed into the vent and into the fill tube. I also drilled into the sender and added a port. the return should work, especially with a cheap low flow pump, but I'd be concerned about pressurizing the return, can cause issues under the hood. the return would be my last choice
I might have pics on here of my fill pipe mod

the grease car valve is an electric valve I'm pretty sure they modify forklift valves and resell them. they're not cheap, but they're pretty good. I never had one fail

like the other guy said, it almost has to be the return line side leaking. if it was the supply side it would suck air not spray fuel
I had one leak on one tank but not the other, i've had one leak intermittently

 

[lsaami]

What trans and rear end? Mine has a monstrous cabover too.

E4OD and 4.10:1 Dana 70. I also have a banks turbo.

I too, have a great, big cabover bed. sleep 6 in 21 feet!

 

[snicklas]

E4OD

That is your biggest advantage. We had a 92 F-250 2wd E4OD and an 88 F-250 2wd C-6 and there was a noticeable fuel economy difference. The OD and Lock-up Converter (especially the lock up converter) make a big difference.

The lock-up is one of the things they are using on the newer vehicles. My 11 F-150 has the 6 Speed automatic. It's actually a Double Overdrive transmission. (4th is 1.14, 5th is .87 and 6th is .69). So the gearing is part of it, plus when driving easy, it goes to the highest usable gear as quickly as possible. Cruising at 55 it at ~1200 RPM. But, this transmission is designed to (and does, I've felt it) lock the converter in all 6 gears. It slips it just enough, and then locks up. If you accelerate, even at low speeds, the engine (in my case a 300 hp 3.7 V-6) will "grunt" and start to accelerate, the RPM's don't jump like an older vehicle would, they ease up, as speed increases. If you push the pedal a bit harder, it will unlock, the RPM's will increase, and if needed then downshift (and it will skip gears on a downshift too).

If you make a spirited takeoff from a light, it will run up through the gears, holding them out, with the converter unlocked, and really get going (if you quickly roll into the throttle to WOT from a stop, I've seen it in the 6000RPM range before it shifts). I've surprised a few passengers with my "little V-6 in a big truck". But, in just "normal driving" (don't have to be first away from the light or up to speed) it will use 1 long enough to get rolling, shift to second and lock the converter, and then step through the gears as reasonably as possible. This is how with a Full Size Pickup (see sig) I can push 20MPG for my mixed commute. Now, throw one of the cute little hair driers on a 2.5 V-6 and that't how Dad's 4x4 SuperCrew can see 25+ It's all part of the design package. The engine has to have enough power (the lowest is the 302 of my V-6) to push the taller gears at lower speeds. I know this is a few decade jump in technology, but it does show the correlation in how fuel economy was gained.

In the Ford Diesels with automatic transmissions:

6.9's - C-6 - 3 speed, no lockup, no overdrive
7.3 IDI - E4OD - 4 speed, lockup, overdrive
7.3 PSD - E4OD/4R100 - 4 speed, lockup, overdrive
6.0 PSD - 5R110 - 5 speed, lockup, overdrive
6.4 PSD - 5R110 - 5 speed, lockup, overdrive
6.7 PSD - 6R140 - 6 Speed. lockup , double overdrive

Yes I understand that some of the economy gained by the gearing is sacrificed in the name of "emissions", but, more gears and more power is how they are doing it. In the smaller trucks the 6 speed that I have, as been replaced with a 10 speed.........

 

[Cubey]

E4OD and 4.10:1 Dana 70. I also have a banks turbo.

I too, have a great, big cabover bed. sleep 6 in 21 feet!

The trans is a big reason why you get better MPG, plus 6ft less weight. Your cabover is probably not like mine. It almost sticks out as far as the front of the hood.

You must be registered for see images attach

 

[Shadetreemechanic]

There are no clip fittings on these valves. It's a bare hose barb for the hose and a clamp.

Just like this gas version.

You must be registered for see images attach

Another example, with factory clamps:

You must be registered for see images attach

I suppose it could be leaking from a hose end, being old, fairly rotten hoses. I will pick up some new Gates hose from O'Reilly and try replacing that first. It needs it, regardless.

That doesn't look anything like the setup on my 85 truck. Sorry for the bad info. I wonder why they did the vans so differently?

 

[lsaami]

The trans is a big reason why you get better MPG, plus 6ft less weight. Your cabover is probably not like mine. It almost sticks out as far as the front of the hood.

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True that, but my 10 mpg is also towing an 18’ trailer (about another 4000 lbs and 4 more wheels of drag).

nonetheless, it’s interesting.

here’s a profile of my cab over for your reference.

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[Cubey]

True that, but my 10 mpg is also towing an 18’ trailer (about another 4000 lbs and 4 more wheels of drag).

nonetheless, it’s interesting.

here’s a profile of my cab over for your reference.

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Yeah your cabover is much more sloped and sticks out half as far as mine. It appears that your RV box isn't as wide too. Wind resistance is a big factor for mpg.

You sure its a 4.10?

Ny F250 NA 6.9 C6 3.55 got 10 hwy pulling a 27ft travel trailer that was slightly taller than the extra tall camper shell. The trailer was much less tall than my motorhome too.

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[lsaami]

Yeah your cabover is much more sloped and sticks out half as far as mine. It appears that your RV box isn't as wide too. Wind resistance is a big factor for mpg.

You sure its a 4.10?

Ny F250 NA 6.9 C6 3.55 got 10 hwy pulling a 27ft travel trailer that was slightly taller than the extra tall camper shell. The trailer was much less tall than my motorhome too.

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my rig is full width, it just appears that way because of the curved edges. My MPG is also based on my odometer, and I know it reads a little slow.

definitely have 4:10s, I decoded the axle ratio from the door tag, and it’s the original to the vehicle. I Spose I’m turbo and that helps with mileage as well? either way, lockup must make a huge difference.

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[Cubey]

I have ATS 085 turbo but no cold air intake.

The air dam on mine needs minor repair and I was too lazy to fix it after I put it on and it slightly broke worse. I plan to work on that after the new year. I doubt that'll give me 1mpg but it might help a tiny bit.

My odometer is very accurate when compared to Google maps distance estimates. The speedometer is off a bit but that's normal. It's less off at highway speeds than a 91 Corolla I had was.


This shows better just how much the cab over sticks out at the point.

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