Need help figuring out my fuel lines on my 1972 suburban

[chuchito]

Does anyone know how the fuel lines are supposed to be routed from the fuel pump to the rear gas tank on a 1972 suburban? My gas tank was removed to install a new one by a shop an now I'm trying to figure out how to install the new one since they just left it.

I don't think that the engine on my burb is the original after researching the suffix code on the engine block(TJC). It currently has a fuel pump with 3 outlets. 1 is to go to the carb and the other two go to the back. Does anyone know where those two lines that go to the back connect to? How are they supposed to be attached to the gas tank( which fittings on the gas tank go to what?). A diagram would be great.

I see diagrams for the trucks but none for the suburban.

[rocknss]

If a 72 is the same as my 69 Burb you will have a rubber hose coming from the tanks sender to the hard line on the frame rail. On mine the hard line is in two pieces with a rubber hose connecting them together. I then have a rubber hose from the hard line to the pump. Then the line goes to a filter and then the Carb.

I'm not sure what the third connection on your pump is for.

[chuchito]

Thanks Rocknss. That's why I am confused as mine has that extra line. Do some Suburbans have different fuel lines for some reason?

[Bigdav160]

Do yourself a favor and download your service manual here

A diagram of the fuel line routing is in section 8

[chuchito]

Thanks Bigdav160. I will take a look at those.

[jfalesi]

C/K 10's have evaporative emissions control (EEC) lines that run from the engine back to the tank and to the charcoal canister. The diagrams in the service manual will help, but I found them to be less than stellar, especially for routing the hard lines. Check the link below for what mine look like at the moment (I'm in the middle of installing a new tank). PM me your email address and I'll send you the pics that Franks 72 sent me. I'll take some more pics of where the lines go on the tank too.

http://67-72chevytrucks.com/vboard/s...d.php?t=685244

[chuchito]

Jafalesi, I sent you a pm. Yes, I especially need pics of where they connect to on the tank and on the canister you mentioned.

Thanks

[Bigdav160]

I thought the service manual pictures were pretty good

[chuchito]

Bigdav, that first picture is a little confusing. Is that for the Suburban? It has the arrow pointing towards the front. If that's the case, it looks like all the hoses are plumbed from the tank over to the rear drivers side where the you would fill the tank from. I don't see any hoses from the tank towards the front right side frame. Am I looking at this picture all wrong? Sorry for my ignorance.

[Bigdav160]

The two lines on the top of the tank are the vents and they go to the fuel separator on the drivers side. The third line goes from the bottom of the separator across (at the bottom of the pic) to the passenger side and connects to the fuel supply line.

[chuchito]

Got it Bigdav! I don't see that I have the fuel separator you are referring to. The below pic shows what came off of my burb.

[chuchito]

Extra pictures

[chuchito]

Side view of passenger rear.

[chuchito]

Side view of drivers side rear.

[Bigdav160]

From the inside, the separator looks like a tube just to the left side filler. under the truck it looks like three pipes hanging down.

[chuchito]

Are all suburbans supposed to have this or only certain ones? Mine doesn't have that anywhere.

[Bigdav160]

Good question.

Mine has California emissions and this is all in place. These pictures are from the '72 Service manual but it doesn't differentiate between California and the other 49 States.

[chuchito]

I ordered a book for my suburban and I think I figured it out. This picture is from my book and it doesn't look anything like the pictures from Bigdav. Mine is a GMC. Maybe that's the difference, I don't know.

[Mikmark]

My 72 has two lines that run to the fuel tank. One brings fuel from the tank and the other returns fuel back to the tank. I think this was to help keep the fuel cooler and avoid vapor lock. The original fuel level guage that fits in the gas tank had a port for the return line. The replacement ones that I have looked at do not have this extra port. I just ran the return line to one of the vent ports. Works OK so far.