84 C10 Gas Tank Refurb

[Ronno6]

I have the bed off my '84 C10. I need to R&R my gas tanks.
Is there a recommended procedure for this?
Do the tanks drop down before removing all the (many) lines/tubes?

 

[Grit dog]

If the beds off it’s pretty self explanatory.
Disconnect hoses and sender and then unbolt it.

 

[Soundmound]

I did it by yoking the bed off. Was much easier for me than the drop the tank method while working on the garage floor. Also, take pictures before disconnecting or better yet replace a line at a time. Lots of tales regarding tank switching issues due to hooking up incorrectly.

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[Grit dog]

The fuel lines are 3 different sizes.

 

[CalSgt]

The fuel lines are 3 different sizes.

Lol… I still managed to screw mine up when I switched to the newer 6 port valve.

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[Grit dog]

Lol… I still managed to screw mine up when I switched to the newer 6 port valve.

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Ha well I’m no genius and I didn’t change anything around. I just played plug n play same for same.

 

[SirRobyn0]

Interesting. My truck is equipped with a dump kit on the factory box so I see the top of the tanks all the time and my sending units are not fully under the cab and can be taken out with the tanks in place and the bed raised. @Soundmound are your tanks 16 gallons or 20s? Mine are both 20 gallon wondering if that make the difference.

This is from when I was installing a new tank on the passenger side, my truck was a factory single tank on the D/S and I wasn't happy with the range.

And before anyone asks, yes that's a D/S sending unit in the passenger tank. For a while the P/S sending units were hard to find, it seems like that might be changing now but never the less they are interchangeable side to side, you just have to run the hoses in a loop and secure them. Like this.

 

[Soundmound]

Mine are 16 gallon and it's a short wide vs. your long bed. Either might be the reason I reckon. I also have the HD suspension and its a touch longer as i understand it, in which direction im not sure though.

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[Soundmound]

Oops accidentally quoted will delete.

 

[SirRobyn0]

Mine are 16 gallon and it's a short wide vs. your long bed. Either might be the reason I reckon. I also have the HD suspension and its a touch longer as i understand it, in which direction im not sure though.

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All good points. Which makes me wonder. Your tanks run back to the spring perches just like mine do. Which makes sense given short bed vs long, but I wonder in a long bed with 16s and they did make them. Generally the single tankers were 20 gallon and if you got an 2nd tank, the second tank was commonly a 16, but two 16s or two 20s were factory configurations. My point, in a long bed with either one or two 16's I wonder if the tanks were slid all the way forward, or back or mounted in the middle. All the squares I've been under at work and I've never paid much attention.

 

[Ronno6]

The show so far.
Passenger side tank is first.
I disconnected the fuel supply, return and vent hoses from the tank.
Well, cut them actually as I would not want to reuse them.......
Dropped the tank, cleaned off the dirt from around the sending unit and removed the sending unit/pick up.
The tank is surprisingly clean. Not going to take much to clean it up and re-install.
The filter sock looks great and the gauge sending unit moves freely and resistance checks fine.
Probably gonna have to replace the selector valve as it doesn't work, but I have not run the electrical test on the harness as yet.
I will pressure wash the outside, clean/repaint the mounting brackets and replace the anti-squeak pads.

 

[Ronno6]

Well, NO tefurb to be done here.........REPLACE !!
The RH tank had apparently been replaced B-4. There was junk yard grease pen marking on top..
While cleaning the exterior there was significant rust on the outside, front and rear.
Pretty deep pitting..........
Inspection of the LH tank shows a wet spot towards the front....... I don't wanna mess around here... 2 new Dorman tanks, a new valve and switch all en route. I wanna do it right.....

 

[Ronno6]

BTW...I had read somewhere that the fuel line sizes are:
Fuel line............3/8"
Return line........5/16"
Vent..................1/4"
Those sizes do make sense
But, that is not accurate per my plumbing.
The vent line is 5/16" and the return line is 1/4"
Looking at the sending unit that makes sense.
The middle pipe is 5/16" and that connects to a chamber that shields it from sucking in raw fuel.
The return pipe is/1/4" and just dumps into the top of the sending unit.
Hose barbs on the valve verify this......

 

[SirRobyn0]

@Ronno6 The correct sizes are
Fuel line 3/8"
Return line 1/4"
Vent line 5/16"
So your truck is setup correctly. Whatever the other thing you read was wrong.

 

[Ronno6]

I guess these guys just don't know...

Need fuel line diagram for dual tanks

Need fuel line diagram for dual tanks

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