HMMWV Fuel Fill Up - Overflows from tank?

[PATRIOT1]

I appreciate anyone's knowledge on this problem/issue. My new-to-me M998 4door fuel tank overflows every time I fill it, and it overflows from underneath/center, not from the fill spout. Anyone else experience this, or know the probable cause? I'm guessing I have to deinstall/reinstall tank and check all gaskets and connections. I'm hoping that one of you knows more?... Thanks.

 

[NormB]

Old, bad gasket on top, or on sender unit, or around vent and/or filler hose.

Find your truck's listing in 24P-1, order all rubber parts from Kascar, Hummerpartsguy or other source.

Plan to drop the tank and replace all parts (including drain plug).

It's on my list of "todos" for our next spring-like week (no garage).

Norm

 

[doghead]

I recall someone recently posting this same issue.

Did you search before posting?

Found this and a few other with a search for "hmmwv overflow" http://www.steelsoldiers.com/showthread.php?144717-HMMWV-Fuel-Tank-Overflow

 

[PATRIOT1]

Thanks guys. It's not always about how to best do something, but this community helps us better understand if this (and many other issues) TEND to happen with a particular vehicle. Thanks for helping me better understand, from your experience.

 

[Retiredwarhorses]

The rubber hose between tank and filler tube is bad...very common, so common I have to replace on every GP truck I get,

 

[86humv]

Every truck I've had that filler hose was dried out and leaking at fuel tank.
To get it off, you need a 2 foot long screw driver [ inboard clamp ].

 

[darr3239]

I was able to get by with tightening the hose clamps on the filler neck.

To get to the one close to the tank I had to wedge a piece of wood between the tank and the frame in order to get a screwdriver in there. It worked.

 

[TedG]

I believe the filler hose clamp was designed to be tightened with small 1/8 size ratchet with 2' extension. Works all the time for me on countless hmmwv's. Steve and Greg's method works too.
The cork gasket is the next common leak point. Drop and replace is best for that along with sender, anything flexible like fuel lines...and new tank, and new everything else! lol. These old girls need a lot of tlc and money...sound familiar?

 

[TLangM998]

The rubber hose between tank and filler tube is bad...very common, so common I have to replace on every GP truck I get,

What size hose do you replace it with? Mine is a funny looking hose, almost looks plastic?

 

[86humv]

What size hose do you replace it with? Mine is a funny looking hose, almost looks plastic?View attachment 734891

Everything is in the parts manual
CPR104420-3 .....nylon tube.