Installing a second tank...questions...

[Nate]

you plum it into the trucks aux port like the other fellow said to do???

 

[steved]

you plum it into the trucks aux port like the other fellow said to do???

Easy, one thing at a time! :-laf



I haven't even gotten that far yet... I just got the system put together... plumbing it into the truck is the next step.



I actually was thinking (since I have such a small flow) of building a manifold out of two 1/2" pipe "tees" (one for a vent, one for an inlet) and cutting a section of the fuel tanks vent hose out... the vent hose is 3/4", so getting hose barbs is easy enough...



steved

 

[Gary - K7GLD]

That's a VERY neat looking install Steve, I know the rest of it is too - here's my own version of routing fuel from the in-bed tank into the vent pipe from the filler neck of the OEM tank:



#ad


Just a simple home made Y adapter made from copper tubing - used it first on the '91, then transferred the whole setup to the '02.



Interesting thread Steve, your setup looks very well thought out.

 

[steved]

That's a VERY neat looking install Steve, I know the rest of it is too - here's my own version of routing fuel from the in-bed tank into the vent pipe from the filler neck of the OEM tank:



#ad


Just a simple home made Y adapter made from copper tubing - used it first on the '91, then transferred the whole setup to the '02.



Interesting thread Steve, your setup looks very well thought out.

Thanks Gary,



Hmm, now you got me thinking about using copper... is your setup gravity fed or pump fed? I'm installing a vent line to the from the main tank to the aux tank as well since I'm putting my fuel into the main tank under pressure... didn't want a catastrophe...



steved

 

[Gary - K7GLD]

Mine is a pump transfer setup - here's a better pic showing the pump and tank-selector valve that I have connected in parallel with the power to the Carter transfer pump - the tank selector valve is used here purely to close off the fuel flow when the transfer pumps is switched off, to prevent siphoning flow from leaking past the pump.



#ad

 

[steved]

Ahhh, ok...



See, I'm going to use a check valve in place of your selector valve... use the check valve's "cracking pressure" to prevent siphoning... sort of a thoughtless way to do it I guess...



How does your main tank vent? That is my main concern... overpressuring the tank if it doesn't vent...



It wouldn't be much more difficult to install the second "vent" line that I'm planning, but if it isn't needed...



steve

 

[Gary - K7GLD]

I never had any venting issues, either on the '91, or the '02, and I've done nothing special to address the issue...



Maybe ignorance IS bliss? :-laf :-laf

 

[steved]

Well, it looks like it's a good thing I kept the Summit pump as it isn't a fitting that's leaking in my setup, it's the pump... the heck of it is, the pump is new, and had never been installed... and I have no receipt to return it...



So now I got to replumb things since the inlet and outlet are opposite from the pump I currently have... but I will be upping the GPM some to probably around 2GPM by the time this is done...



Sucks I need to replumb it since it turned out so nice to begin with... oh well.



I did get my checkvalves today... they should work just as I planned... you can hardly get these to pop trying to blow through them, so they must be around 1psi.



steved

 

[steved]

As another update... found a couple REALLY interesting things:



First, I got it hooked up and running last weekend (but not yet hooked to the OE tank). I had it plumbed in a loop/circuit so that it pumped from the cell, through the pump, to the separator, to the filter, and finally back to the cell. So I decided to test the water separator/WIF light... dumped about a quart of water into the cell (containing around 5 gallons of fuel) and proceded to "catch" it, or so I thought.



Turns out having the pump between the cell and the separator causes the water and fuel to be emulsified as it passes, and therefore the water would not separate from the fuel... I ended up with a big foamy mess being return right back to the cell (past two water separators mind you!!!).



What I found interesting about this is the fact this pump is very similar to that of a 2nd gen carter by design. In less thatn 50k with my FASS, I have drained more water out of the separator than either my dad or myself have drained out of our 99s' OE fuel system in over 450k worth of miles, combined. This leads me to believe that the fuel/water is passing through the OE pump, getting emulsified, passing through the OE filter, and getting run right through the engine... my little mistake makes me pretty confident about that statement.



So, part of last weekend's job was replumbing the system (yet again) so that it now runs: cell, separator, pump, filter, cell (or later, main tank)... sorta the same flow circuit as a FASS or Airdog.



Forward to last night. Decided to drain the mess out of the cell and clean it... I proceded to pump it into a 5 gallon can and the WIF light popped on!!! Turns out the emulsified fuel partially separated from the water and I was catching water with the replumbed setup. And the WIF light (and my homemade sensor) works!!! So after I drained everything, I wiped the inside of the tank out (lucky for big openings in the fuel cell) and cleaned everything up one last time. I ended up catching at least 90% of the water I had initially placed into the tank!!! So my separator works!!



Hopefully this weekend I can get it finally plumbed into the truck's tank so I can end this project!!



Oh, and my checkvalve works just like I thought it might... the cracking pressure prevents any siphoning, yet still allows a pretty good volume of fuel through!



steved

 

[MCummings]

I built an electronic circuit that monitors the signals to the main tank and bed tank fuel level gauges. When the voltage on the main tank hits a certain value the transfer pump is started. When the voltage on the main tank hits a different value the transfer pump is stopped. If the voltage on the aux tank hits a certain voltage the transfer pump is disabled.



If you want the details and to discuss the circuit e-mail me at -- email address removed --



You have to know a little electronics in order to do this. There is a complication. The sending unit in the bed tank may not work with the same values as the one I have. The circuit would be very similar, but the voltage detection for the bed tank would have different values.

Steved, Very nice job. Excellent alternative to the 800+Lb aux. fuel tanks available now.



Joe G. I would be interested in those instructions as a transfer tank in the bed will be in my future... (I'll hit you up when ready)



Merrick

 

[steved]

OK, well I got the system plumbed in...



First, the pump will actually partially collapse the cell (it's only plastic), which I find odd since I have it vented to the main tank.



However I did find that it works as well as planned, I will just need to vent the cell. I think I will drill and tap the cap and simply install a 1/8" vent. The system works fine with the cap loose... after the main tank fills to the top, then the excess fuel is returned to the cell.



steved

 

[DennyDay]

JoeG

If y'all put a line voltage timer in place of the on-off switch (15min. type) to run the transfer pump, you don't have to worry about running main tank over. Ya, I got CRS several years ago!



Its a Home Depot or Lowes item.



Denny

 

[Joe G.]

Denny,



I consided that. Decided I wanted more control over what is going on. The other thing was that I needed a good excuse to build something using modern electronics. I worked in electronics in the early '60s. That was quite a while before ICs and other such things.

 

[steved]

Well, I decided to yet again change plans... I took the FASS's return adapter off the fill line. Drilled and tapped it for a 1/4"NPTx3/8"barb fitting and reinstalled it. I have not redone the "manifold" on the vent (not enough time), but simply plugged one line (left the vent in place) and attached the new fill.



So far, the barfing fuel has stopped, although I got to reinstall my check valve (anti siphon device... !!!) as it will siphon the cell dry if I don't turn the valve off...



I head for Minnesota tomorrow morning, so Iguess we will find out how things work!





steved

 

[steved]

you plum it into the trucks aux port like the other fellow said to do???

I checked my 3rd gen and they don't have a spare port... only the two 1/4 inch roll over valve barbs that cause so much problems.



steved

 

[steved]

Well, to finalize this project I will only need to replace the OE vent line to the tank. If you remember I added my own fill/vent fitting to the 3/4" vent hose for both a fill and vent... it didn't work. So I got another vent hose and will remove the "fill" fitting from the vent hose so there will only be the "vent" into the vent hose.



I have ran probably 500 gallons through this setup to date... I found that simply opening the valve will start the siphoning effect... don't even need the pump except to "top off" the main tank to the same level each time (in the filler neck) or if I run more than my aux's 22 gals out.



I will say that I have found a lot of water. And the scary thing is I have found a lot of water in the main tank (caught in the FASS). My only explaination is the ULSD is hygroscopic and literally absorbs water. Since installation, I have drained over a gallon of water out of my filters/separators.



My water separators are working... of the THREE, only two seem to catch much water... the primary and the FASS. The small FS1251 doesn't seem to ever get much of anything, but as I noted earlier... the pump might be emulsifying the water?? I would guess that the water in the tank is happening AFTER the fuel is transfered... condensation??



Now that I have had time to run this setup, when I get back into traveling, I will probably just run with the valve open, gravitiy feeding the main tank constantly. This will allow me to make quick fuel stops, which will still be every 300 miles. Basically, I would not even bother "topping off" the main tank.



Would I do this again?? Yep. I wish I would have done this sooner. Even though I don't use this for extended range... the safety factor of an extra 22 gallons is nice...



Would I used this small of a tank again? Ehhh, probably since I still have the slide in to deal with. If I ever get rid of the camper, I will probably go with a 100 gallon "L" under the box. If I have a facility that I could lift anything out of the bed, I would definately have a much larger tank.



Would I build a separator again?? Definately, without question.



Would I use the pump again?? Probably. I like being able to gravity and force feed if I have too. But don't get me wrong, it isn't necessary.



steved