Unused port on fuel sending unit?? pic inside

[DTL]

I saw in my brief search that a capped 3rd line leaving the fuel tank is not uncommon on these trucks, but does anyone know if it is a vent or a pick-up? I'm looking at adding an in-bed fuel tank and I'm wondering if I can use this spare fitting as a fill point.

Edit: picture was upside down. d'oh!

 

[dstang97]

I dont want to guess, but I think that the gassers and the diesels use the same part. That would go to the charcoal canister. Hopefully someone will know.

 

[DTL]

I *could* just pull it and see, but as you can tell from the picture, GM (in their infinite wisdom and foresight) placed the sending unit EXACTLY between the cab and bed. Basically, they force you to drop the tank to pull the sending unit. Of course, I have a full tank at the moment. Jerks.

 

[dstang97]

I was able to get mine out without dropping the tank.

 

[southdave]

The extra I belive is for an artic kit or personel heater.. I would check the TM to confirm but I am pretty confident

 

[BIG_RED]

I was told it was for draining the tank but I never looked into it.

 

[blackhueys]

draining the tank is what its for. the stock fuel line has a t fitting up by the pass side tire area just under the flap this is where the arctic heaters connect to.

 

[Westech]

I dont want to guess, but I think that the gassers and the diesels use the same part. That would go to the charcoal canister. Hopefully someone will know.

Ding ding ding.... we have a winner

 

[notsosanestan]

would be a good spot to pressurize the fuel system when trying to start her after changing filter or running out of fuel

 

[southdave]

I thought the cargo compartment heater was to tie into it tm is vague from diagram

 

[kentuckycucv]

Maybe i can hook up a fuel pump to it for my smoke screen generator. Does it drw from the bottom of the tank or is it a vent?

 

[hemi348]

Maybe i can hook up a fuel pump to it for my smoke screen generator. Does it drw from the bottom of the tank or is it a vent?

It draws from the bottom of the tank. Have fun post pictures

 

[ssgtcampbell77]

I saw in my brief search that a capped 3rd line leaving the fuel tank is not uncommon on these trucks, but does anyone know if it is a vent or a pick-up? I'm looking at adding an in-bed fuel tank and I'm wondering if I can use this spare fitting as a fill point.

Edit: picture was upside down. d'oh!

Your middle line is a drain. The line closest to the cab is your return and the line closest to the bed is your feed. Reference TM 9-2320-289-20 page 3-32 and figure 3-13. And Im wearing flip flops.

 

[southdave]

Your middle line is a drain. The line closest to the cab is your return and the line closest to the bed is your feed. Reference TM 9-2320-289-20 page 3-32 and figure 3-13. And Im wearing flip flops.

That stupid cut away dwg throw me allittle, I was looking @ 1008/a1 install. my bloody toed old buddy, I stand corrected..

 

[K9Vic]

draining the tank is what its for. the stock fuel line has a t fitting up by the pass side tire area just under the flap this is where the arctic heaters connect to.

Or on the M1010 for the rear heater unit.

 

[DTL]

I was able to verify that it feeds from the bottom of the tank. We needed a little fuel for the heater the other day so one of the guys pressurized the tank slightly. We were able to freely draw the 5gal we wanted from that capped port. Hopefully I'll never *need* to drain that tank, but if I do, it's cool that there's a fitting in place to do so!