Sitting on bombs? (CJ gas tanks)

Hi everybody. I've no jeep yet, but will have one soon. But I'm no newbie to 4x4 ownership.

I've gone back some 15 pages in this section over the past few weeks and I'm wondering what is the problem with stock mounted gas tanks in early CJs? I'm very safety-consious and if there is a Pinto thing going on, can somebody enlighten me?

Thank you!

 

I personally don't like one under the seat mainly for accident purposes and cabin fires, but a large chunk of them have a fume problem and you can smell gas. I have a 71 with the factory tank in the rear where its suppose to be (my opinion), but if you don't like it under the seat it is really not a big deal to move it to the rear, having it in the rear also gives you extra space under the drivers seat along with a better smelling cockpit!! There are however alot of guys on this board still running these Jeeps with the tank under the drivers seat without alot of complaints.

 

The fumes are not so bad with only a bikini top. Although I mostly agree with Mike, I have never heard of any major problems. Hell, you have to die from something?!

Mark :v6:

 

I had a '73 with the rear mounted tank, and added the under-seat tank for more fuel capacity. I was young and foolish then, and would not do that today. The rear-mounted tank is inside the frame, and outside the cabin (passenger compartment). Reading about the Pinto, it seems that the unibody Pinto had very little structure to keep the tank in place in the event of a rear-end collision. The Pinto, in a rear-end collision, combined terrible spillage with separation of the floorpans and jamming of the doors that, with ignition, would place the occupants at great risk.

We can only speculate about the relative hazards of side-impact collisions, and whether the fuel tank or the collision poses more of a hazard. We can, however, make a pretty good guess about where the safest location for the fuel tank is given the existing Jeep body and frame. I'd say the rear mounted tank, inside the frame and outside the body, is the best location. The rear under-the-floor design is still used today for Wranglers, which I assume undergo collision testing. You might want to take a look at a Wrangler and compare the tank mounting and placement to older Jeeps. The rear tank is a fairly easy retrofit for Jeeps with the underseat tank.

Of course, for a CJ that isn't driven regularly in traffic, collisions are less of an issue.

 

been around Jeeps all my life
have never heard of a single explosion/fire incident involving an underseat tank
I have 2 of them in my Jeep
that's not to say it couldn't happen

 

My opinion also... I have an underseat tank that used to fume me out pretty good. I took the sending unit out and made a thick gasket for it out of some paper gasket material. No more fumes

 

put some pipe dope on the return line plug fixed the fumes on mine.

 

my thought is if i take a hard enough hit on the drivers side that it splits my tank then i took one heck of a hit. but to make myself feel a little better about my tank under my tailbone i got a plastic tank. they will deform long before they crack.

 

Think of it as a space age safety feature. Nobody used seatbelts then, so in the event of a severe impact, the explosion of the fuel tank would actually propel you and your seat safely away from the scene of the accident. Sounds good in theory.

 

You either have a smaller gas tank underneath you or a tank twice the slze 3 feet behind you. If saftey is a concern I would worry more about brakes, steering, and a well grounded electrical harness. Not to even mention, and some here would dissagree, a solid roll cage and 3-pt seatbelts. A good poly tank, or a new steel one, with a new sending unit you'll have no fumes.

 

Wow, what an active forum! Thanks for your replies.

I suppose this is sort of like the Chevy/GMC truck "sidesaddle" tank controversy. I guess I'll have some things to think about (and smell for a while! ).

I don't want to reveal too much about the CJ5 I'm due to get ahead of the transaction lest it jinxes things, but it DOES have dual-underseat tanks!

 

duel? cool. ive thought about that. it might be in the future for mine, i figure my passengers should have the same kind of ride i do :twisted:

 

:twisted:

 

Ditto here too. I get hit that hard I'm done anyway! No problems with it other than smallish capacity. Fumes are not too bad. Yes, you'll smell some gas but it shouldn't be overpowering.

Stan

 

Hey, I appreciate the sentiment. Fatalism is an appealing rationale.

[on soapbox]

Let's be realistic. You can't seriously argue that the rear mounted tank isn't safer than the under-seat tank. The rear mounted tank is both outside the passenger comparment and inside the frame. Rear mounted tanks are also equipped with anti-rollover valves - they aren't supposed to spill at all with the rubber-side up. A rollover with an under-seat tank puts any spillage in your lap, or close by.

Less safe means increased risk. We don't really know how much safer because noone has crash tested an ECJ5 to compare with the later models with a rear underfloor tank. I doubt that Kaiser, who moved the tank to the rear, even bothered to test. They probably were compelled by Federal regulation to move the tank out of the passenger compartment.

So how much risk is there? You can decide. If you drive your Jeep in daily traffic, you run a risk of having a collision, period. The more you drive, the higher the risk. Driving, in itself is dangerous, typically the single most dangerous thing we do every day. Are you sitting on a bomb? No. Is the under-seat design older and less safe than the under-floor design. Of course. Is the under-seat tank the largest and most easily corrected risk of driving an ECJ5? Probably not.

[/off soapbox]

 

I suppose what's cool about dual underseat tanks is that you can fill them up semi-tractor style -- a gas pump hose on each side at the same time -- that'll make a cool avatar.

I may be mistaken but I thought it was AMC that first moved the gas tank to the rear? Odd though, Ford was still putting gas tanks in the cab behind the seats in the early 80's.

 

Don't think so my dads new 77 pickup had it inside the frame rail under the bed. Ford quit putting tanks inside the cab on the there f series trucks long before the f150 came out. It was federally mandated to be changed by something like 1971-72 on all vehicles.

Amc bought kaiser Jeep in 1970 , the gas tank thing I would bet my life was already in the works, nothing in the auto industry like this would be done in less than a year and since most of the 1970 models had the tank in the rear I would say it is a good bet the Kaiser already implimented the go ahead before the buyout was even discussed.
To give you an idea of what I am talking about, you and most others have probably heard about an H3 version of the Hummer, we were quoting parts for this beast way over 1 1/2 years ago and it still isn't out yet, we also produced the first body parts for the Titan truck more than 1 1/2 years ago and they have only been on the showroom floor for about 7 months.

 

Just to throw out another thing here concerning gas tanks and fires. There were only a total of 28 people killed from tank explosions in the Ford Pinto, there were more than 1800 people killed from the side saddle tanks in GM's pickup trucks.

I'll leave mine in the rear end where it goes, theres no way some idiot is gonna light a match or something near my Jeep with me sitting on 11/12 gallons of fuel that has vapors coming from it and a filler spout 8' from my left arm, with just 8" and a softtop from me and the flame, I've seen to many burn victims, and there is no pain on earth like burning, Thats one chance I'm not going to take!!