Fuel cap hole?

[DREDnot]

I did a quick search here, and looked at the -24P and did not see anything that goes in this 1/4NPT hole in the fuel cap.
Or is this cap not correct/original GI?

 

[Ronmar]

Mine dosnt have one of those... Handy way to prime the fuel system(or splode the tank)...

 

[frank8003]

Hole is useful for recirculating fuel thru a filter. Just put a pipe plug in it and/or build a real fuel filter for it.

 

[Ronmar]

Or adding fuel from a bed tank or barrel...

 

[coachgeo]

I just figure it was for a chain to bolt thru the cap and attach to tank so a soldier does not loose the cap.

 

[DREDnot]

Yeah, I got a pipe plug to seal it off. Just wanted to make sure it wasn't a missing vent, or NBC filter or some other weirdness.

Sent from my SM-G970U using Tapatalk

 

[Ronmar]

Mine has one of those, but it is on the inside of the cap...

 

[coachgeo]

Mine has one of those, but it is on the inside of the cap...

Mine has a chain attachment hole inside too. (and chain) It connects to the large screen in the tank..... but since the screen lifts out.... then soldier raised in the city loses BOTH of them... .... thus why figured some may have at one point had an external cap chain as well. (or came off a different truck M939? with hole for same reason) Good ol' farm kid probably not..... he done been putting diesel in the tractor for years and knows how easy missing cap absorbs moisture out of the air into the tank and FUBARs things.

 

[wandering neurons]

I can tell you from experience, that's a strong chain that attaches the filter basket to the fuel tank cap. I've got a locking cap on my LMTV. Opened the cap with keys in the cap. Filled the tank, replaced the hose, drove off. Drove 60+ miles including some dirt road, till I got to my stopping place and realized that I'd left the cap off. Cap was still attached, keys still in the cap! Everything was covered in silt and diesel fuel, but worked fine!
And no, I don't have a hole in the outside of my filler cap other than the one for the key to unlock it. Maybe someone had a locking cap and removed the locking mechanism?

 

[NDT]

Me thinks that is a field mod used to pressurize the fuel tank to get fuel flowing fast to the IP etc.

 

[coachgeo]

Me thinks that is a field mod used to pressurize the fuel tank to get fuel flowing fast to the IP etc.

or to solve a venting issue quick and easy

 

[DREDnot]

Maybe someone had a locking cap and removed the locking mechanism?

It came straight from Ft. Hood as a non-runner. I'm on board with the air pressure port theory. The tank was bone dry and relatively clean...