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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: 1979C20 on February 12, 2011, 03:37:25 pm

Title: Fuel return hose
Post by: 1979C20 on February 12, 2011, 03:37:25 pm

Any chance I can get a diagram of the fuel hoses for dual tanks on the truck in my sig? When I dropped my passenger tank a few months ago to check the sending unit, my hose was cracked and dry rot. So, I left what I believe is the return hose off. And I just recently started going through a lot of fuel in the past month, I crawled under my truck 2 weeks ago and found the my to pump hose on my tank selector was leaking, so I tightended the hose clamp. Now, last night I lost almost a half tank driving ten miles. I crawled under my truck and there was fuel sprayed all over my frame rail. And it looks like its coming from the steel line for the return hose?

Title: Re: Fuel return hose
Post by: Grim 82 on February 12, 2011, 07:17:48 pm

Quote from: 1979C20 on February 12, 2011, 03:37:25 pm

So, I left what I believe is the return hose off. And I just recently started going through a lot of fuel

Replace the fuel line. Whatever gas the motor is not using is being shed back through the return hose and you are spraying it on the ground. I don't have a diagram of the routing, but from the pump you have a feed and a return back to the switch valve, and then a feed and return to the left tank, and a feed and return to the right tank. The bigger 3/8" fittings are the feed line and the smaller ones are the return. If you have vent lines to the cannister they will be the smallest of the 3 different sizes, and they are just teed together and run to the charcoal can seperate of the valve.

Title: Re: Fuel return hose
Post by: 1979C20 on February 12, 2011, 11:48:54 pm

Well, theres only 2 lines on my fuel pump. From the selector and to thr carb

Title: Re: Fuel return hose
Post by: Grim 82 on February 13, 2011, 11:26:20 am

So where is the line that you left off? If you put it back on you should be good to go.

Title: Re: Fuel return hose
Post by: 1979C20 on February 13, 2011, 03:05:03 pm

I need to finish bolting my new engine mounts back in today so ill snap a pic. Can I just cap it? Vb I really dont want to drop the tank again.

Title: Re: Fuel return hose
Post by: Grim 82 on February 13, 2011, 03:23:00 pm

I'm not really sure what you have there. All of the pumps I have seen have 3 ports; a feed, return, and one to the carb. Yours may be different because it's a different year, I don't know. I don't think you can get away with just capping it but I can't say for sure. How many ports are on the selector valve?

I would put it back the way it was before it started giving you trouble, even if that means dropping the tank again. That sucks but I think it's the right way to go.