Aux Fuel Tank plumbing

[Ranger]

So, I've got a 45 gallon tank in the bed of the truck. Didn't have parts or time before the holidays to get it squared away, so I made do with a harbor freight rotary pump... and on the trip from NV to MI I grew very tired very quickly of using it on the roadside to top the truck off at 20 degrees or less.

So, I got to working and got the parts to go from the discharge port on the tank, to fuel line, to a electric diesel fuel pump, to more hose line.

I get .5 gal/minute flow, which is acceptable.

Thing is, I just tried routing it via some fittings into the breather line for the tank... and apparently I'm deadheading the pump or something, because I have no flow whatsoever into the tank. I don't know why. I remembered having read other people do just that in lieu of interfacing with the filler neck... and although I could rig something up that would work for the filler neck, I would rather not have to.

Any suggestions? I have about 4-5 days to get this squared away before I have to drive back to NV and pack/move to MI permanently.

 

[LtEng5]

Norther Tool part for the filler neck is the best route. can be done from under the truck with the hose in place - no need to remove fill hose.

Do you have a filter of some sort in line some where? I use a "performance" in line glass filter ( the ones you see just before a carb on some "hot rods" ) between the aux tank and pump. What are you using for a on/off switch to control the pump?

 

[Ranger]

Right now I don't have all my tools to wire it up to a switch, so it's redneck as all getout with a $5 radio shack 15' cig lighter cord... manual switch on the cheap. I don't have a filter since the tank was newly pressure tested and cleaned... stock filter will be fine.

So the vent line just won't work? I'm just trying to avoid having to stop with an interim "make it work" so I can just plug the cig lighter bit in and go. I'm at 1/4 tank and the best thing I can guess is that there's a no-backfeed mechanism in the vent line because the pump's going but I had it going for 30 minutes with no change in main tank level.

The northern tool bit is one I've looked at, however I don't think that it'll be something I can just up and get in the next 3-5 days, even locally.

 

[RI Chevy Silveradoman]

The Northerntool kit is a gravity feed system that has a valve to prevent overflow when full.
Is there a vent on the auxillary tank? I wonder if it is vapor locked?

 

[Ranger]

Aux tank has a vent. I will go try it for 30 min right now w/ the aux tank cap off just to test. I am not, nor can I, gravity feed. The tank has a bung for a bung type transfer pump, a discharge which draws from the bottom of the tank and it's end (and where my lines start) is basically on top of the tank.

I know the electric pump has enough power to pump, it's pumped off this setup albeit without being into the vent line...

SO, testing ensues. I can open up a vent more if it's what is causing the problem.

 

[WarWagon]

You need a vent line from the breather fuel fill neck hose to the aux fuel tank. Transfer flow uses a double pipe that has both a fill and vent on the same part that tees into the fuel tank vent line.

 

[Ranger]

That doesn't explain why with both fuel caps off, I still had no flow from the aux to the primary tank after 30 minutes of running.

The pump with all the lines I currently have on it functions with .5g/min flow, out of the aux tank.

The only explanation at this point is that there's a fluid restrictor of some sort in the vent line as a rollover protection device.

Now I'm going to go with plan B, which is a "poor mans neck adapter" because I'm at an inlaws house and will be driving back to nevada before the weekend, so buying and getting anything shipped in time isn't a guaranteed thing, and I'm not waiting on anything other than signing on this house unless I HAVE to.

I'll drive to NV with my tank cap off for the truck and the hose fed down the filler neck if I have to, but I'd rather not.

 

[WarWagon]

Factory vent lines do not have any rollover devices in them. I have the transferflow hooked up on my 2005 and had it on a 2008. You may have a kink or plugged screen somewhere including in the pump?

 

[RI Chevy Silveradoman]

It does not sound like a venting issue after reading your posts. If it were a venting issue, removing the cap and running the pump would take care of it. So I doubt it is a vapor lock type issue.
My next response is the same as WarWagon's. Maybe a kink in a hose, or a plugged screen in the pump, or just plain the pump not working correctly? Seeing that it is a Harbor Freight, I would recheck the pump. I hate to say it, but they are very cheap pumps. If it is the pump, you should be able to get a decent replacement pump with Viton Seals at any RV shop.

What is the brand name on this auxillary tank? Did you get it brand new? Could it have any sludge inside the tank preventing it from pumping?

 

[Ranger]

the pump i WAS using was a rotary manual pump from HF. The electric fuel pump is from Summit and worked with this exact same setup, pumping fuel at .5g/minute, nonstop, up until it was hooked to the vent line.

 

[RI Chevy Silveradoman]

OK. What brand auxillary tank is it? Or is it homemade?

 

[Ranger]

It's a western.

Disconnected it this morning, hose was pressurized, tank was not.

Into the fill tube I go. Pumped fine.

There's either a blockage in the vent line, or a fluid restriction/back-flow prevention device inline.

The aux tank, pump, and fuel hoses are known good, functioning as intended/desired... the goat rodeo is the stock tank.

Now to find a 3/8" male to male fitting to reconnect the vent line to where it should be from it's interim ziptied location, and put a small hole in the filler neck to plug a barbed fitting into. I have no problem setting a stopwatch to top the tank off some, I think I'll also avoid the whole "gauge stuck" event as well if it's shifting from more to less. Hasn't given me a hard time so far cycling this way.

never mind that the RDS kit would simply give me a port. I wouldn't put any money on that float system keeping closed with any actual pressure, and my little green pump will do 15 psi.

 

[RI Chevy Silveradoman]

Glad to hear that you got it figured out. Have a safe trip home and please keep us updated as to the permanent fix and solution. :thumbsup: