6.2 fuel sending unit problems

[andyh1956]

I found this in my CUCV manuals.
GM part # for Fuel, Tank Meter on M1008 is 25004137.
For the M1009 it is 25004140.
The units are different between the M1008 & M1009

[hatzie]

The M1009 is a Blazer chassis with the tank between the frame rails.
M1008 M1010 M1028 & M1030, I think I got em all, are pickups with saddle tanks.

[andyh1956]

By looking at the illustrations, the M1009s have four outlets & M1008s have three. The center outlet on the M1008 hooks to a short piece of tubing that drops over to inside the frame & has a cap on it. They list this assy as a "Tank Drain".
I spose you are to hook a pump onto this & suck the tank out.
I'll look in my TMs for the procedure.
But in the short run it looks like a feature not needed for our purposes.

[hatzie]

You really only need vent, supply, and return for the diesels. The tank drain is superfluous.

GM stopped installing the tank drain in the Civvy rigs around 1984 or 1985 or so. Since the military spec for the trucks was based on an early 1984 chassis, and the military gets nervous about changes, they kept building them exactly the same til Uncle Sam stopped ordering them.

If it's stock pre mid-84 you'll find a valve somewhere around the spring hanger on the frame. It may actually be inside the spring hanger. The TM will probably tell you. You can get rid of this drain line unless you're going for exactly original.

[andyh1956]

Originally Posted by hatzie

You really only need vent, supply, and return for the diesels. The tank drain is superfluous.

GM stopped installing the tank drain in the Civvy rigs around 1984 or 1985 or so. Since the military spec for the trucks was based on an early 1984 chassis, and the military gets nervous about changes, they kept building them exactly the same til Uncle Sam stopped ordering them.

If it's stock pre mid-84 you'll find a valve somewhere around the spring hanger on the frame. It may actually be inside the spring hanger. The TM will probably tell you. You can get rid of this drain line unless you're going for exactly original.

"SuperWho"???

[hatzie]

superfluous
[soo-pur-floo-uh s]

adjective

1. being more than is sufficient or required; excessive.
2. unnecessary or needless.
3. Obsolete. possessing or spending more than enough or necessary; extravagant.


Ahh tends ta use them thar big words sometaahms.

[andyh1956]

This forum is FULL of $10 words today!

[barry1982]

I had a similar problem with a 6.2 after we changed out a leaking fuel tank. The truck would start, run for a few min., then stop. Ran perfect before we removed the tank, so I knew it was something we did. Pulled the tank off again, and turns out one of the short rubber hoses that go from the fuel line to gauge/sending unit got kinked while installing. Unkinked adjusted hose, reinstalled tank, ran like a dream.