I ax this question every year or so, and have never got a good answer, but here goes again.... Does anyone really know why is the F100 panel gas tank located inside the frame, instead of outside (where there is room), where it is on the F100 pickups?

Just curious.

 

Dunno.... but sure gets in the way for dual exhast.... I put the tank in the rear ( Behind the differental )

 

Yeah, it's one of those hard to explain things. For all I know, all the panels had tanks inside the frame, and, after the first one, they just kept putting it there.

 

I would assume the reason the tank was in between the rails is for safety. If it was mounted outside of the frame, only covered by the exterior sheet metal, they wouldn't have much protection in a side impact collision. The tanks in the conventional cabs, like the pickups, are behind the seat up until 1973 I think. According to a 1948 sales brochure I have, trucks that were made without cabs also had the between the rails tanks like the panels. These were trucks built and sent out to have custom bodies installed on them like delivery vans.

A lot of people get nervous having the tank behind the seat but it has to one of the safest places, in my opinion. That area would be the last area affected by most collisions. I have never heard of any problems with this arrangement, unlike most Mustages and the Pintos in the early to mid seventies with their rear mounted tanks and terrible results in rear end collisions. The one problem I see with the in the cab tank is fumes, this was discussed last week in another post on this forum but you just have to be careful and maintain your truck and there won't be any problems.

 

I agree with Bob's assessment on this. Believe it or not, Ford was thinking about safety, no matter how crude the effort was back then. Also 76 was the last year for a in cab fuel tank from Ford. 77 , they started with tank fillers in the bed. What confusion that created when we had to order body panels for pickups that were hit!

Barry

50 F-1

 

The tanks in conventional cabs were not all inside; 53/56 F100s did not have in- cab tanks...only the 56. The 53 to 55's were between the left running board and the frame, cradled on the running board supports. If it was a question of either in cab or inside frame, I agree that safety might be the reason; however, I was referring to inside of frame vs. outside of frame differences. (53/55s), so safety wasn't involved.

 

In comparing inside the frame to outside the frame, safety still could be part of the reasoning. Having the tank inside the frame is much safer than outside the frame.

But that still doesn't explain why panels differ from pickups.

 

Just a thought, but what about a practical load balance advantage to handeling? Putting the tank closer to the center of the truck instead of on the outer edge. Just my $.02 worth.

 

Hmmm ... supposing you do get fumes in your cab from a stock tank in the stock location .. would keeping your windows open prevent issues?

 

If you're getting fumes inside the truck, it usually means a leak of some sort. Gasket around sender, hose for filler pipe, loose hose clamps, rotted filler pipe, fitting at bottom of tank or even holes in tank?

Barry

50 F-1

 

A related question: Why did the 56s put the tank INSIDE the cab, but the 53/55s are on the frame?

 

It sounds simple. As stated above the '53-'55 pickups had the tank between the running board and the left frame rail. Panel trucks did not have running boards like the pickups... and as I am writing this I am now having doubts since the panel trucks do have some sort of running boards, don't they???? I am going to have to look at a picture of a panel now. Let me look at my literature and spec books fo diagrams.
Later, abe

 

Panel trucks have running boards, slightly different from pickups; in fact, they use the same frame including running board mounts. The only noticable differences besides the gas tank location is that the panel frame has bolted in short frame extensions at the rear; these are also used on long bed pickups of that era, and the rear pickup cab mounts also aren't used with a panel body.