Steel Pickup tubes

[Wreckclues]

I'm curious, my 1976 M813 had a steel pickup tube in the fuel tank. Mike Virili at Big Mike's motorpool thought it was "kind of odd to me that steel was used...Most of this stuff would have been copper in the fuel tanks, but it could have been changed out by someone who used what they had to make a repair at some point." MsgtJD also thought it was kind of odd as in his experience they were brass. Now I've found two other members who have experienced steel pickup tube problems. Superthermal's 1979 M813 and Dumpy198's 1991 M925A2.
Has anybody else had steel pickup tube issues?

 

[NDT]

Oh yes, they are notorious for getting pinhole rust holes allowing a troublesome air-fuel mix to get to the engine.

 

[87cr250r]

Copper reacts with the sulfur that used to be present in diesel fuels.

 

[TomTime]

Although my truck is different (it is a 5 ton) and newer it had steel pickup tubes that were rusted, had a couple of pin holes, but worse it was almost completely clogged with rust.



Removed and replaced them with Stainless Steel tubes. I've had great experience with stainless steel pickup tubes over the years.


Tom.

 

[msgjd]

I have recently discovered one of the tanks on my M817 has a steel pickup tube, and coincidently the one I started having trouble running the engine from, last week after the tank got less than 3/4 full .. Filled it and it ran fine .. Yup, pinholes

 

[Wreckclues]

So what's the common denominator on steel tubes?
So far it's just 5-tons from the 1970's to 2002 (if I'm reading TomTime's post correctly)
Does this mean all 5-ton's have steel tubes?

 

[Jbulach]

Nope, my 1991 M925a2 had a copper pickup and rubber return down tube. Replaced them both with stainless, even though the copper was in excellent shape, rubber was rotten and coming apart, still fighting pieces of it sucking up against my pickup . Will try to check my M923a2 tomorrow when I pull the filler neck off.

 

[Jbulach]

1990 m923a2 is the same, however the baffle in the fuel tank is different and I believe they may be from a different manufacture but hard to tell with all the CARC on the tag.

 

[TechnoWeenie]

Big Mike's has copper tube for $50. I haven't inspected the one on my 923A2 but I figured it was cheap insurance, since I'll be redoing all the fuel lines anyway.

 

[Wreckclues]

Big Mike's has copper tube for $50."

I cobbled one together from straight copper pipe soldering in the old threaded fitting.

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