Titan 30gal Aux Spare Tank

[2manyprojects]

Titan 30 gal aux spare fuel tank

I’ve rec’d multiple inquiries and didn’t see much info on our forums for this tank since I installed it a year ago, so I thought I’d provide some details and my experiences. I performed the basic tank install April 2021 w/ 2900 mi on my truck, with about 20K miles driven since. My truck was purchased to pull an off-road trailer and I’ve got multiple other trucks w/aux and o/size tanks, so I really wanted something for my Tradesman. Going to 37” tires prevented using the OEM under bed spare location, so the tank seemed perfect to substitute. I did consider the o/size main tanks also available but wasn’t crazy how most are lower than the OEM tank and frame rail; I can still go this way in the future. I also was concerned with the CP4 pump warranty issues for the new truck and didn’t want to modify the OEM fuel system initially.

The Titan kit is quite comprehensive, provided everything needed, with thorough instructions and well written. There are also YouTube videos which further helped clarify details. Titan was very helpful when contacted with questions on the function of the transfer pump and controller. Their tech person explained the pump needs to flow fuel at a slow rate (30 gph), otherwise the Ram fuel system will signal problems as they learned it can’t cope with sensing the fuel increase too rapidly while driving.

I elected to sub some components for personal taste, but quality was acceptable. The supplied low pressure fuel pump never worked for me; I decided to use a better-quality solid-state pump I got locally from NAPA. I didn’t discover this until well after I had purchased, so I didn’t approach Titan for a replacement.

I also made a few custom mods for my use, detailed later.

Installed pics



Pros

• Range between fill-ups; w/ 60 gals onboard, I’m able to go at least 900mi highway cruising (500 towing).
• Doesn’t occupy bed space, although my choice of fill location requires in-bed access.
• Adds 250lbs weight to the rear axle, for winter traction.
• Pretty much invisible on truck.
• Tank and peripherals are light, molded plastic less than 50lbs.
• Extends time between fill-ups when not traveling; delays dealing w/ current crazy fuel costs.
• Functions w/ Ram systems w/o issues.

Cons

• Price has increased greatly since I purchased 1.5 yr ago.
• Takes up spare location.
• Adds 250lbs behind the rear axle.
• Requires cutting into the bed to install fill port.
• Cost for a total fill.
• Tank is molded plastic, thicker wall than OEM tank, is similar to MFC’s (mil fuel can) but even heavier duty. I’m impressed with the construction, but it isn’t steel, if that’s your comfort zone.
• Occasionally leaks a small amount of fuel from the tank breather. I’ve traced this to filling the tank and topping off too much in the morning, then getting a significant temperature rise during the day. I now fill w/o topping too much and transfer a small amount of fuel when the main tank slightly empties.

SUMMARY: I’m very satisfied overall. On board fuel has doubled, while I can selectively transfer as desired. The controller is straightforward, and the system works. With my mod, I can transfer fuel other places if needed. It adds weight to the rear axle, which I value in the winter, but has presented some challenges in how I load when towing. I can feel it when full driving, but it’s not detrimental. Unfortunately, the price has dramatically increased since I purchased, and makes the value harder to justify. I think it’s more versatile than an o/size replacement tank, but the cost difference has changed.

 

[2manyprojects]

INSTALL DETAILS / MODS

(Full instructions can be downloaded from the website linked in the 1st post)

I was able to do most of the install in my driveway alone. The tank is awkward but light (<50lbs). It helped to remove the rear bumper and left rear fender liner. The plumbing is straightforward, but very tight to the underside of the bed, and requires bed seam trimming and patience to get everything aligned, connected, and clamped. With my location for the fill port, it was awkward to connect the fill and vent hoses, but doable.

The aux tank fuel transfers to the OEM main tank by splicing a double tee into the OEM main tank fill port vent line. A small inline low psi fuel pump w/filter is connected, as well as a vent/overflow line to equalize pressure as the fuel flows between. It’s not difficult, but very challenging (for me) to make the splice. This direct-transfer pump was mounted from an existing hole behind the rear fender, near the left front of the bed, as well as a small inlet filter. The pump is pretty noisy but can't be heard while driving or when the engine is on unless you're standing next to it.

Out of paranoia over the CP4 debacle I decided to first install the tank and manually transfer fuel when needed using my Fill Rite pump mod explained later. With the recall now initiated I felt more comfortable connecting to the OEM fuel system, so I added the direct transfer pump early 2022. It isn’t difficult, but I couldn’t figure out access, so I paid a local shop I trust to do this. It was added expense, but it got me through my impasse.

FILL PORT: You have to decide where to mount the fill port, which requires a 4.5” hole cut into Sheetmetal. The common location is behind the rear wheel opening, same height as the OEM. Titan provides a good quality billet Al metal cover with a thick black rubber gasket to accommodate the flat cover fitting onto the rear fender contour. While I’m sure this works just fine, I felt it would look cobbled close by the OEM recessed main tank fill cover. I came up with a potential way to recess it into the fender, but couldn’t find a local body shop willing to work with me, so it got shelved.

I then shifted to the alternative Titan suggests, which is to install it in the left rear inner bed side. I planned to replace the OEM fill cover with a black locking model, and luckily the unit was interchangeable w/ the Titan unit so I bought two and machined the 2nd to fit the OEM side recess in the inner bed wall. This basically gave me two matching, locking fill covers, using the same key, with the aux tank fill port concealed inside the bed area. This works fairly well and is stealthy, but requires opening the tailgate to access. With my lifted truck and Softopper installed, the bed step is very helpful to draw the nozzle and hose around to get it inserted. The fit and angle with my Softopper on is tight, but reasonable with practice. I also have to deal with a few diesel dribbles in the bed.


TANK INSTALL: the spare winch assembly is removed and replaced with bracketry that holds a 10” long ¾” threaded rod. The tank is then moved up into position with this rod protruding thru the center of the tank. A large round steel plate goes under the tank into a molded recess and held w/double ¾ nuts onto the rod. This is all that holds the tank into the truck; it has been very solid w/ no issues so far.

FILL RITE TRANSFER PUMP MOD: Having a 2nd diesel truck and hoping to add a diesel heater to my trailer, it occurred to me it would be beneficial to be able to draw fuel from the aux tank, separate from the truck. I replaced the plastic elbow/ hose barb for the tank outlet with a brass tee. To the tee I connected a hose barb for transfer to the main tank, and a 10’ rubber ¾” fuel supply hose to the other side. On the opposite end of the ¾” hose I added a quick disconnect hose fitting, to match a mating fitting on an RD-7 Fill-Rite Fuel Transfer Pump. I fab’ed a plastic cover out of a jar for the hose end and fittings, and attached a length of paracord which was threaded up through the bed wall, close to the fill port. This allows me to retract the hose up inside the sidewall of the bed. To transfer fuel, I lower the hose, connect it to the inlet of the pump, plug the pump into 12V power I wired to the rear bumper for the trailer, and place the outlet nozzle wherever I need to deliver fuel. Switch the pump on and pull the nozzle lever to flow. It has a reach of about 15’ and will pump all 30 gal in about 5 min. I have a 2nd inlet hose which can be used to pump from anything it can be submerged into.


CONTROLLER: Titan supplies a small electronic device you can Velcro onto your dash. It has a row of ten orange LEDs showing tank level, a small LED indicating when the pump is on, and a button to turn the pump on/off. It’s pretty bright, but gets washed out with direct sun and can be dimmed by holding the button. I elected to power it from my SwitchPro, so I can turn it on as needed and also operate it when the engine if off. To transfer fuel the button gets pressed and the pump runs for a fixed time, delivering about 5 gals. It shuts off when the aux tank level reaches empty but doesn’t communicate when the main tank fills; I haven’t intentionally overrun it, but have had no issues with overfilling.


To date I've had no issues with the pumps or any of the hardware. The tank remains well connected, and I often leave it filled and just work off the main. I love it when towing, as it provides a lot of flexibility when traveling remotely. I just can't fathom why the $$$ has increased so much....

 

[UglyViking]

Super interested in this setup. I had been toying with it for some time but always looked like the spare tank was going to sit too low and ruin both departure angle (not that I end up using it a ton) and be a visual eyesore. Looks like quite the opposite on both counts! I guess I've just got to suck up the price, which is getting to the point of being a bit more than I can stomach. They have always been spendy, but this seems excessive.

The fill port is the major thing to consider for me personally. I'm toying with using the bed space to sleep, and am worried about spills and fumes in the bed of the truck. I don't think I could live with it on the outside of the bed. If I had a flatbed of some sort it would be one thing, but currently I think it would be a bit of an eyesore on the outside.

 

[2manyprojects]

I struggled w/ the fill port placement, as mentioned in my write-up. What I considered real hard, but couldn't follow through on was to recess it like main tank using this clip:
Rear Fender Panel
Figured I could use the fuel port portion and basically cut the hole and bond this piece to the back side of the sheet metal of the fender w/3M adhesive. I wanted locking fuel doors, and had those located, so it would/should have matched up and looked acceptable. I tried multiple local body shops to get some help w/paint, but couldn't get anyone to even consider it.

I haven't slept in back, but the Softopper seals fairly well and I haven't noticed any significant odor FWIW.

I've had two Toyota trucks w/aux tanks, and they used fill ports that were mounted in the rear of the wheel well. It looks strange when you're filling, but works fine. It also got mud slung on it there, but that was mitigated by putting a cover over it, or making a small door in the wheel well liner, similar to the light access panels we have in the front wheel wells. With the lifted Ram there's space but would take some fab work.

Brings me back to why I mounted it in the bed...