2021 JLUR - Jerry Can spare tire mount and vent questions

donmontalvo

Member
I have been using RotoPAX fuel containers for a few years, but the caps have become harder and harder to use. I'm tossing in the towel and moving to a 20L Jerry Can.

My 2021 JLUR has a Smittybilt heavy duty tire carrier (7743), and I'm running 317/17R70 tires mounted to ICON Rebound Pro wheels.

Questions, or sanity checks, here's what I have built out...
  • Is it possible to add an aftermarket vent, so I can equalize the pressure when I'm in Moab (cold nights, hot days) or Colorado (elevation changes)? if so any recommendations? I found something on Amazon, made for fuel cans, not sure if they'll work with metal.
  • I use a RockSlideEngineering EZ Rack strapped onto a 35" tire, on a tailgate reinforced with a SmittyBilt tire carrier (which replaces the factory hinges for strength).

I put together the mount with the bracket and Jerry Can, but I haven't mounted it yet. I have confidence this setup will be fine, but happy to stand corrected.

IMG_5420.jpegIMG_5421.jpeg1682919159989.png1682919196865.png1682919242897.png
 

donmontalvo

Member
Update: apparently there are folks running this configuration. Their advice included using the highest rated bolts, nylon-lock nuts, and washers that fit in the recessed bolt holes of the Wavian mount (Home Depot baby!).

They also recommended getting a flexible nozzle because the CARB nozzle that's included is a PITA to use (I'll have to see for myself). Just keep it strapped down tightly and should be fine.

I'll have my 5LB propane tank on the passenger side of the spare tire. I hope to visit the Southern Texas off road BOH trails in an upcoming weekend, will get a chance to camp out a few days and test this setup.
 

Peter_n_Margaret

Adventurer
Is it possible to add an aftermarket vent, so I can equalize the pressure when I'm in Moab (cold nights, hot days) or Colorado (elevation changes)? if so any recommendations?
It is my view that relieving the pressure in fuel containers is counter productive.
It is caused by the vapour pressure of the fuel which is a direct consequence of the fuel type and the temperature. Relieving it does not make it go away, but will simply make more fuel evaporate until the pressure is again established.
The fuel vapour that is let out is also dangerously flammable.
Leave it in the can.

ps... my preference for fuel containers is high quality cross linked polyethylene. I would not use steel containers if they were free.
Cheers,
Peter
OKA196 motorhome
 

donmontalvo

Member
It is my view that relieving the pressure in fuel containers is counter productive.
It is caused by the vapour pressure of the fuel which is a direct consequence of the fuel type and the temperature. Relieving it does not make it go away, but will simply make more fuel evaporate until the pressure is again established.
The fuel vapour that is let out is also dangerously flammable.
Leave it in the can.

ps... my preference for fuel containers is high quality cross linked polyethylene. I would not use steel containers if they were free.
Cheers,
Peter
OKA196 motorhome

Interesting viewpoint. I'm not sure I trust plastic gas cans. Whether they're Sceptor or RotoPAX.

I decided to move away from plastic since they're difficult to use when they're bloated due to high heat or elevation gain:

CD542CE7-9308-4312-BAFD-4037F303495E_1_105_c.jpeg0E72D243-9CF7-491D-B5E2-F845D57E2C97_1_105_c.jpeg

...or concave due to cold.

DBE1598D-DC4B-473D-A982-5986ECEBDAAF_1_105_c.jpeg8D76C133-326B-4543-A3F3-4A1BFA5D30F6_1_105_c.jpeg

The cap on the RotoPAX is a horrible design if either of the above conditions exist.

Buddies who use Wavian NATO cans moved away as well, and they love it. They told me to (1) get a flexible nozzle since the CARB nozzle stinks, and (2) add a pressure valve. I ordered a flexible nozzle, should be in tomorrow. The valves came in, and they seem extremely well made and low profie.

I'll have to see for myself if things get better. I didn't have fuel cans at Moab (EJS) last month, even though it isn't really needed, it's something I always want to carry, spare fuel.

I have two trips coming up. One will be over the Memorial Day weekend (May 27-30) and it'll be to two TX trail parks. Northwest OHV Park, and Falls Adventure Park. I'll use that trip as a dry run, to get used to using the Wavian NATO cans.

The next trip will be to Colorado (Aug 10-15), to do Black Bear Pass, Poughkeepsie Gulch, Imogene Pass, and if I have the nerve Holy Cross. I plan to rent cabins while I'm there, unless I can find a group that plans to use tents. That'll be when I'm fairly certain the Wavian NATO cans will be needed.

After those trips I'll be able to decide if the move from plastic to metal is the right move, and whether I need to worry about bloat/concave pressure issues.

PS, I wouldn't be surprised if your point is proven, maybe plastic is better due to flexibility...however those RotoPAX caps are horrible. :)

Thanks,
Don
 

donmontalvo

Member
20L Plastic Jerry Can | Containers | Fluid Handling | Products | HAIGH Australia PTY LTD
These are the only ones I use. Available in 20L, 10L and 5L.
20L is AUD$35-40 and is available in black, red and yellow.
I have some that are 30 years old. Never had a failure.
Cheers,
Peter
OKA196 motorhome

Those look great! Guessing since they're plastic they'll bloat (hot/elevation) and concave (cold), which is more of an eyesore than anything else.

But if the caps work in those conditions, maybe I should have tried those first. Do they come with a RotoPAX type of mount so I could put onto the spare tire?

Thanks for the link!
 

fourfa

Observer
I've got 4x Scepter MFCs, plus the special tool, plus the special pour spout, plus spare seals and flanges, plus the seals and flanges I've had to replace over the years. For many years I fed a thirsty Tacoma from those MFCs, filthy from being outside the vehicle, filth on my hands, spilled all over myself and the truck hoisting them up high. Spent a lot of time strapping them in, unstrapping, checking strap tension, checking lid torque, dealing with leaks, burping and managing pressure and temperature and sun exposure in all those separate cans. Built a rooftop carrier with a metal bar through the handles to reduce the strapping and unstrapping. It all adds up, in money and time and headache

New truck, one of the first things I got was a single large aux tank in the bed (Gladiator, and I had the space to spare). Single tank, single siphon hose, single transfer, single seal, single pressure-relieving cap. No handling, no strapping and unstrapping. Just drop the hose in and shake, and walk away until it's done. One of the best things I've done. There's more to this than just the price tag up front.

(Also Titan has a "scratch and dent" sale area. I got a scratch and dent Sidekick for a fraction of the full price, and there was literally nothing wrong with it. Worth keeping an eye out maybe.)

A little more flavor:
 

fourfa

Observer
Well, re-reading the OP I see you're only looking for a single can, so maybe most of what I wrote doesn't apply. I've often needed to carry 4 cans (20 gallons) as many of our trips in and around Death Valley can burn half a tank just getting from the nearest gas station to the trailhead. That situation doesn't leave one much choice, you just gotta carry a lot
 

donmontalvo

Member
Well, re-reading the OP I see you're only looking for a single can, so maybe most of what I wrote doesn't apply. I've often needed to carry 4 cans (20 gallons) as many of our trips in and around Death Valley can burn half a tank just getting from the nearest gas station to the trailhead. That situation doesn't leave one much choice, you just gotta carry a lot
I lived in CA for a couple years, before I owned a Jeep. CA and AK next year, probably a 30 day vacation. Not sure if I'll splurge on a trailer, if I do, I'll definitely bring a couple/few fuel cans. For my May/Aug trips, 5 gallons should do it. I wasn't aware gas stations were so far from Death Valley, yikes!
 

Peter_n_Margaret

Adventurer
Those look great! Guessing since they're plastic they'll bloat (hot/elevation) and concave (cold), which is more of an eyesore than anything else.

But if the caps work in those conditions, maybe I should have tried those first. Do they come with a RotoPAX type of mount so I could put onto the spare tire?

Thanks for the link!
Yes they bloat, but as you suggest, so what?
The twin caps actually seal. They have replaceable O rings, but I have never needed to replace one.
They fit a standard steel jerry mount.
Oz made. Maybe not available in the USA?
Cheers,
Peter
OKA196 motorhome
 

donmontalvo

Member
The flexible nozzle came in today. Swapping out the CARB nozzle was pretty easy. The plastic bracket that holds the CARB nozzle in place is mounted using two rivets, where the flexible nozzle bracket came with a couple screws. Once I removed the rivets and the bracket, I installed the new bracket using the two supplied screws. 10 minutes later, I was done.

I'll fill the can and mount it to the spare tire tomorrow, then I'm off for a weekend camping trip. I just hope I don't get rear-ended, with 5 gallons of fuel and 5 pound propane tank mounted to the spare tire. :) I guess that would be a problem no matter what you choose as your solution.
Flexible (top) and CARB (bottom).CARB (left) and flex (right).Carb riveted retainer bracket.Removing the two rivets.If you're careful, no paint will chip.
New flexible nozzle bracket thingy.CARB bracket (top) and flexible bracket (bottom).Flexible bracket attached to bracket thingy.Before view (CARB).After view (new).
 
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