Installing a second tank...questions...

[steved]

OK, here is my plan:



Going to buy a 22-gallon fuel cell and sit it in my extra wide/deep crossover box. I am still on the fence about whether to buy a steel one or plastic one... the steel might rust, but the plastic might be attacked by the diesel... but that's something I have asked Summit Racing...



I fully intend for this to be a pressured feed, not gravity... in other words, I will have a pump and filter feeding the main tank... probably going to either run a Carter or Holley for the pump... I already have a FS1251 filter and head.



I also (now) intend on installing a line from the main tank's vent to the fuel cell's vent... as well as the feed from the cell to the main tank... this should prevent pressurizing the main tank and causing it to rupture.



Now, what do you anticipate happening in the event the pump fills the tank? I was imagining the fuel filling the neck to the vent, then the pump simply circulating fuel back (through the vent line) to the cell... and not pressurizing the system... does this sound likely?



Any other hints or concerns? I am planning on getting the needed parts this weekend from Summit... would really like to hear from anyone else you has completed this using a pump to feed the main tank for the auxilary and see what problems were encountered...



steved

 

[Sled Dog]

OK, here is my plan:



Going to buy a 22-gallon fuel cell and sit it in my extra wide/deep crossover box. I am still on the fence about whether to buy a steel one or plastic one... the steel might rust, but the plastic might be attacked by the diesel... but that's something I have asked Summit Racing...



I fully intend for this to be a pressured feed, not gravity... in other words, I will have a pump and filter feeding the main tank... probably going to either run a Carter or Holley for the pump... I already have a FS1251 filter and head.



I also (now) intend on installing a line from the main tank's vent to the fuel cell's vent... as well as the feed from the cell to the main tank... this should prevent pressurizing the main tank and causing it to rupture.



Now, what do you anticipate happening in the event the pump fills the tank? I was imagining the fuel filling the neck to the vent, then the pump simply circulating fuel back (through the vent line) to the cell... and not pressurizing the system... does this sound likely?



Any other hints or concerns? I am planning on getting the needed parts this weekend from Summit... would really like to hear from anyone else you has completed this using a pump to feed the main tank for the auxilary and see what problems were encountered...



steved

Steve, your going the long way around the barn. JMHO I have a 160 gal. rectangular aluminum semi tank. Gravity feed into OEM tank, constant feed = OEM always full.

Yes I have gate valve between. Absolutely, No problems. Just keep your fuel cap on snug. Been that way for a year and half.

 

[steved]

Steve, your going the long way around the barn. JMHO I have a 160 gal. rectangular aluminum semi tank. Gravity feed into OEM tank, constant feed = OEM always full.

Yes I have gate valve between. Absolutely, No problems. Just keep your fuel cap on snug. Been that way for a year and half.

You can't gravity feed from a fuel cell because they pull out of the top of the tank... you could easily lose the siphon effect.



Plus I have to have something small enough I can pull it out when I need too... I have a 77-gallon saddle tank (currently in the for sale section), but it is too big.



steved

 

[Sled Dog]

You can't gravity feed from a fuel cell because they pull out of the top of the tank... you could easily lose the siphon effect.



Plus I have to have something small enough I can pull it out when I need too... I have a 77-gallon saddle tank (currently in the for sale section), but it is too big.



steved

I did not know that, thanks. Good price on the saddle tank.

 

[EKlem]

Just throwing out another option here. You could put a 6 port solenoid valve in your fuel lines and plumb the two tanks into it so you choose which tank you pull out of. That way there is only one fuel pump(assuming that you don't have an intank unit). You can get a valve by pollak from JC Whitney that will do the job. This is what a lot of the guys running grease do. I realize that it may not suit your needs but it is something to consider.



As far as material goes, there are a lot of plastic fuel tanks made for diesel. I have run many in boats and never had any problems. I don't know whether they are dot approved but you can get marine fuel tanks pretty easy.



You mentioned that you want the tank to be removable. I have had good luck with using hydraulic lines and quick disconnects. It is really nice because there is no fuel spill and it is quite easily done.

 

[steved]

As far as material goes, there are a lot of plastic fuel tanks made for diesel. I have run many in boats and never had any problems. I don't know whether they are dot approved but you can get marine fuel tanks pretty easy.



You mentioned that you want the tank to be removable. I have had good luck with using hydraulic lines and quick disconnects. It is really nice because there is no fuel spill and it is quite easily done.

Yeah, been looking at marine tanks too... my main problem is finding a "nice" size. A think I narrowed it down to a 22 gallon fuel cell from RCI.



I had thought about the hydraulic connections... I'll need to stop somewhere and inquire about some 3/8" or 1/2" NPT versions.



I am also going to attempt to make a water separator with a WIF light... going to use a length of 3" or 4" schedule 40 PVC pipe, probably 15" long... glue ends on it... place the inlet in the side and outlet in the top (I might even put the inlet so it discharges downward from the side)... place a WIF sensor (maybe even make one) in the side about 1/2 way up... and install a petcock in the bottom cap (it will sort of stand on one end, using the bottom part as a sump...



So now I'm going to have: tank, pump, WS, filter, main tank.



I am really paranoid about getting another slug of water since I never fuel in the same place twice... that is the main goal of this setup... warn me of excessive water before it gets into the main tank...



Probably start the install this weekend... I have everything but the tank, which I can get later.





steved

 

[DogDiesel]

I use an electric fuel pump

Same pump since 1996. Same 50 gallon cross bed tank. Pull from the top of the bed tank, with an internal rubber line in tank, weighted with a pickup screen. Gives me over 85 gallons total. Can run the bed tank dry and worry only about the OEM tank level.

Only issues I have had. Must keep OEM tank lid tight, this prevents gravity flow. I'm good for 900-1100 towing miles, according to load. Searching for a few cents less to fill takes on a new meaning with the shock of putting $200 in fuel or more at once.

Wayne

 

[Joe G.]

I have a similar setup to Wayne's. The only real problem I have had is CRS. I have forgotten that the pump was on a few times and oiled down some tailgaiters. Don't mind that so much, but I don't want to waste expensive fuel on tailgaiters. I have developed a pump controller that turns on the bed tank pump when the main tank is low and turns it off if the main tank is full or the bed tank is empty.



My 50 gallon tank is removeable so I can haul loose stuff like rocks if I want.

 

[steved]

Same pump since 1996. Same 50 gallon cross bed tank. Pull from the top of the bed tank, with an internal rubber line in tank, weighted with a pickup screen. Gives me over 85 gallons total. Can run the bed tank dry and worry only about the OEM tank level.

Only issues I have had. Must keep OEM tank lid tight, this prevents gravity flow. I'm good for 900-1100 towing miles, according to load. Searching for a few cents less to fill takes on a new meaning with the shock of putting $200 in fuel or more at once.

Wayne

How do you vent the OE tank? I mean, you are filling a "sealed" container right? Or is there a vent somewhere?



What happens when the OE tank gets filled? Do you keep an eye on the level or will it just quit filling?



If I could get away with a single line from the Aux to the OE tank, I'd be happy.



Steve

 

[steved]

I have a similar setup to Wayne's. The only real problem I have had is CRS. I have forgotten that the pump was on a few times and oiled down some tailgaiters. Don't mind that so much, but I don't want to waste expensive fuel on tailgaiters. I have developed a pump controller that turns on the bed tank pump when the main tank is low and turns it off if the main tank is full or the bed tank is empty.



My 50 gallon tank is removeable so I can haul loose stuff like rocks if I want.

Where does the fuel exit from when the tank is full (or should I say overfilled???)? Hmm, this is sounding more like a one liner now!



I guess I just got to get under there and finger it out.



steved

 

[DogDiesel]

Venting OE Tank

On my truck, the OEM venting system is the same from factory. I have my upper tank fill to the lower OEM tank via Tee at filler neck. Absolutely, a case of can't--remember--stuff could cause overfill of lower OEM tank. However, with my factory ratcheting filler cap, it vents but prevents leak if properly tightened. My little electric pump is one of the Carter pumps same as inline 6. 2/6. 5L trucks. It is a fuel transfer setup, low volume--low pressure. So far, I have wasted no fuel (knock on wood so to speak). DOT rules state such set-up tanks are not covered in regulations, only tanks 100gallon or more must have DOT /OSHA approved transfer setups.

Also, I can stop and open the lower filler cap, release air pressure and speed the fuel transfer significantly. Admittedly, this is not the optimum setup, but it works for me. When I visited my wife's family in Kalifornia, I filled in Nevada, drove to Redding and filled again in Nevada. That is nice. I only have to fill once per day on average when towing. Rest breaks are not at the fuel pump. Again, while not the perfect setup, it works and I am not inclined to change it yet. I like the idea of shut-off devices. Would like to hear more.

Wayne

 

[steved]

I like the idea of shut-off devices. Would like to hear more.

Wayne

I agree, a shut off would be nice.



I would like to know where the fuel runs out if the OE tank is overfilled... that way I could figure something else out... I have a feeling it is from one of two places, the rollover valves or the filler neck cap...



I still think I'm going to run the second line since the tank is equipped with it... it would make filling a lot faster and prevent any fuel loss (hopefully!) :-laf I currently have a very small Facet pump (27gph@0psi, unknown gph @5psi max)... but I feel it would take too long to transfer if you were in a hurry...



steved

 

[Nate]

Northern Hydraulics sells a kit to slice into the fill neck, I'm thinking of picking that up.

 

[Joe G.]

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]

Northern Hydraulics sells a kit to slice into the fill neck, I'm thinking of picking that up.

I'm just going to pull the FASS's return line splice out and weld another fitting into it... same principle though...



steved

 

[steved]

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.

Probably more than I want to get into at this point, but it sounds cool... like a tick tock switch...



steved

 

[Joe G.]

Northern Hydraulics sells a kit to slice into the fill neck, I'm thinking of picking that up.

The 2nd gen trucks have an auxilliary input in the fuel tank modules. It has a plastic cover. Just remove the cap and put the transfer hose there. I don't know about 3rd gen tank modules.

 

[steved]

The 2nd gen trucks have an auxilliary input in the fuel tank modules. It has a plastic cover. Just remove the cap and put the transfer hose there. I don't know about 3rd gen tank modules.

I guess I'll find out this weekend...



I have/had a smallish pump... something like 4-7psi, 1/4" in/out, and 27GPH... so I might just use that...



We are going to get the pump/dropout/filter hooked up this weekend. then I'll take another time to hook the cell in and plumb it into the main tank.



steved

 

[steved]

Wellllllllll... .



Ordered my fuel cell last night, a 22-gallon RCI... the -8AN fittings were giving me fits to the point I ended up ordering a new 140gph/14psi Summit pump too... my little POS pump was 1/4" and there was no easy/clean way to adapt from1/2" hose to 1/4"NPT... but this should give me ample volume that I could fill it, run it into the main tank, then fill it again for added volume... I'll be running 1/2" line from the tank to the pump, then 3/8" line for the remainder of the setup...



And again, I am not building this tank setup for the added travel distance thing as much as I'm building it to knock large quantities of dirt/water out of the fuel... I am seeing water in almost every tank now for some reason... and while the FASS is doing a good job, it makes me nervous not having a WIF sensor somewhere...



Hopefully I can have this mostly installed this weekend...



steved

 

[steved]

Done: Pictures...



Entire setup took about 5 hours taking our time...



The fuel filter is a 10 micron Fleetguard FS1251 bobcat filter...



The separator works quite well... I am flowing 0. 5GPM, so when that hits a 4" pipe, everything not fuel falls out...



The WIF sensor turned out good too... I used two brass screws about 0. 5" apart... during "testing", we had them over an inch apart in a pop bottle and it easily lit an LED.



steved