gas cap style

when did they change from the short gas cap to the tall ones? Did all H's and M's have the short ones? Paul

As part of the deal when IH was taken over by Tenneco and merged with Case, Navistar, the new name for the old International truck division was made responsible for giving free tall gas caps to anyone who wanted one. The reason was the danger of fire, which so I have read has happened. At some point before the merger IH stopped making the small ones and began making the tall ones. CaseIH still sells them. So there are two sources until Navistar no longer sells them. I don't know if there was an actual serial break.

IH had some serious law suits due to fire when the cap either leaked or someone opened it and it had pressure in it. Replaced a lot of them and also every IH dealer was issued a tool to reform the gas tank cap locking mechanism for a proper fit of the new cap. New cap is double baffled to reduce leakage and keep vent from plugging and causing pressure buildup. Didn't help when a guy smoking a cigarette opened the cap from what we were told. Another bad one was the placement of the battery on the early model cub cadets. Some one shorted a metal gas can against the battery live terminal so there was a law suit over that. I think it was a young kid but not sure. Never know if the stories you are told are correct or not. Case also had a gas cap replacement program that went right along with IH with the merger. I think IH put a end date on the program at one time but the gov't stepped in again and said, no way. It may go on forever.

(quoted from post at 20:39:31 07/29/12) when did they change from the short gas cap to the tall ones? Did all H's and M's have the short ones? Paul

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The "new" style, triple baffled, caps were first available in the late '50's or some time in the '60's.

The original caps had their vents on the underside of the cap. In an attempt to limit fuel leaking due to splashing in the tank the designed was changed to a single vent in the top center of the cap. In a further attempt to limit the problem the design was changed to a triple baffle design the required a taller cap. This design also had one single vent in the top of the cap.

The law suits dealt with pressure building up in the tank and being released suddenly when the cap was removed. This was due to the vent plugging on the top of the tank. The sudden release of so many vapors was blamed for many fires.

The current design includes two vents on the top of the tank plus a double latch on the bottom so the cap can not blow off if there is pressure in the tank and the cap is removed rapidly. The cap must be turned another 1/4 turn or so after it is loose before it can be removed from the tank filler opening.

The free gas cap replacement program is for gasoline engine tractors that have fuel tanks mounted above and behind the engine. Diesel engine tractors and those that have the fuel tank located behind the operator seat do not qualify for the free cap. The fuel cap replacement program is a liability that Tenneco did not assume when they bought the IH Agricultural Equipment Division. That is why it is still handled by Navistar.

The current triple baffle design must be different from earlier "tall" caps.

I remember back as a kid around 1980, Dad put new gas caps on the M, 560, and 756. Both the 560 and 756 already had "tall" caps on them, but they got new caps anyway.

I can't remember if the dealer gave him the caps or if he had to send away for them, but they were definitely "free."

If all tall caps were "safe" then IH wouldn't have included the later model tractors in the settlement.

This is from the www.ihgascap.com website.

A serious fire can occur during operation of a GASOLINE fueled tractor. Under certain conditions, gasoline vapors can build up pressure in the gas tank. If the gas tank cap is then removed, while the engine is running or hot, the sudden release of pressure could force gasoline out of the tank and result in a fire. Gasoline can also escape if the gas cap is not securely tightened. Never remove a gas cap from a hot or running tractor. Always tighten the cap securely. [b:94b7c5cacb]A new style gas cap, first available in 1980,[/b:94b7c5cacb] has special design features to reduce gasoline vapor build-up and fuel eruption due to improper gas cap removal. The new gas cap has two vent holes in the top of the cap and has “PRESSURE - OPEN SLOWLY” embossed on the top of the cap.

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Brings back memories of the old H. On hot days working it hard sometimes the gas spurted out of the gas cap vent until dad bought one of those "tall" gas caps. At least the tank isn't directly over the engine.