Fuel Sending unit lines ? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Nvbowtie · 09-19-2003, 04:47 AM

I have my new sending unit, it has 3 lines I will only be using the large draw line from the tank to the fuel pump.

I did away with the canisters and there is no return fuel lines.

What should I do with the other two line outlets on top of the sending unit ? plug em ??? do any need to breath ???

79BIG10 · 09-19-2003, 06:24 PM

I plugged my return lines off when I replaced the fuel line to the pump from the valve on the bed rail. The other I think is a vent but I routed my vent lines together where the charcoal canisters were. I would vent one with a breathable cap where fumes go out but nothing comes in.

Nvbowtie · 09-19-2003, 09:06 PM

Quote:

Originally posted by 79BIG10
I plugged my return lines off when I replaced the fuel line to the pump from the valve on the bed rail. The other I think is a vent but I routed my vent lines together where the charcoal canisters were. I would vent one with a breathable cap where fumes go out but nothing comes in.

breathable cap ????

79BIG10 · 09-20-2003, 12:28 AM

It's a cap that goes inline. It's a vent cap like on the rear axle. It has a vent tube there as well.

Nvbowtie · 09-20-2003, 01:11 AM

Where can you buy it ?

79BIG10 · 09-20-2003, 01:14 AM

Not sure on that. Probably a auto part store. Tell them you're looking for a cap for a line that needs to breathe but still be able to keep stuff out.

**swervin ervin** · 09-20-2003, 01:36 AM

I'm just wondering if you can still buy vented gas caps. They probably don't sell one to fit a unleaded fuel tank. I'm not even sure you can buy any vented caps anymore.

But, if you can, you could cap off the vent/charcoal canister line. If not, you will need a filter/cap on this line so gas vapors can escape the tank, or else it may just rip the tank wide open. I know you've seen plastic gas cans blow up like a balloon when all the vents are shut. It would cause problems it would seem to me.

Nvbowtie · 09-20-2003, 04:21 AM

I guess I could just run the two lines out toward the body with a restricted opening so it could breath ?

Maybe use some type of filter like hog hair ???

77bowtie · 09-20-2003, 07:51 AM

I blocked off the 2 other lines (vent & return) and drilled an 1/8" hole in the center of my gas caps, to vent my tanks. Has worked fine for over 20 thou miles.

09-19-2003, 04:47 AM	#1
Nvbowtie Registered User Join Date: Jul 2001 Location: Laughlin, Nv. USA Posts: 700	Fuel Sending unit lines ? I have my new sending unit, it has 3 lines I will only be using the large draw line from the tank to the fuel pump. I did away with the canisters and there is no return fuel lines. What should I do with the other two line outlets on top of the sending unit ? plug em ??? do any need to breath ??? __________________ www.unlimited2u.com/chevy Bill 1980 Chevy C-10 Silverado 1988 Chevy Blazer Tahoe

09-19-2003, 06:24 PM	#2
79BIG10 I'm back with 2nd truck! Join Date: Feb 2002 Location: Texas Posts: 3,775	I plugged my return lines off when I replaced the fuel line to the pump from the valve on the bed rail. The other I think is a vent but I routed my vent lines together where the charcoal canisters were. I would vent one with a breathable cap where fumes go out but nothing comes in. __________________ 1979 Chevrolet Bonanza Big10 "Tootsie Roll" 1985 Chevrolet Silverado (wife's) Member of the Southern Bowties Club "Don't underestimate how sexy a fat man who drinks to excess can be." Homer Simpson

09-20-2003, 12:28 AM	#4
79BIG10 I'm back with 2nd truck! Join Date: Feb 2002 Location: Texas Posts: 3,775	It's a cap that goes inline. It's a vent cap like on the rear axle. It has a vent tube there as well. __________________ 1979 Chevrolet Bonanza Big10 "Tootsie Roll" 1985 Chevrolet Silverado (wife's) Member of the Southern Bowties Club "Don't underestimate how sexy a fat man who drinks to excess can be." Homer Simpson

09-20-2003, 01:11 AM	#5
Nvbowtie Registered User Join Date: Jul 2001 Location: Laughlin, Nv. USA Posts: 700	Where can you buy it ? __________________ www.unlimited2u.com/chevy Bill 1980 Chevy C-10 Silverado 1988 Chevy Blazer Tahoe

09-20-2003, 01:14 AM	#6
79BIG10 I'm back with 2nd truck! Join Date: Feb 2002 Location: Texas Posts: 3,775	Not sure on that. Probably a auto part store. Tell them you're looking for a cap for a line that needs to breathe but still be able to keep stuff out. __________________ 1979 Chevrolet Bonanza Big10 "Tootsie Roll" 1985 Chevrolet Silverado (wife's) Member of the Southern Bowties Club "Don't underestimate how sexy a fat man who drinks to excess can be." Homer Simpson

09-20-2003, 01:36 AM	#7
swervin ervin You get what you pay for Join Date: Dec 1999 Location: Cherryville, NC Posts: 4,798	I'm just wondering if you can still buy vented gas caps. They probably don't sell one to fit a unleaded fuel tank. I'm not even sure you can buy any vented caps anymore. But, if you can, you could cap off the vent/charcoal canister line. If not, you will need a filter/cap on this line so gas vapors can escape the tank, or else it may just rip the tank wide open. I know you've seen plastic gas cans blow up like a balloon when all the vents are shut. It would cause problems it would seem to me. __________________ Mike 1985 Chevy C-10

09-20-2003, 04:21 AM	#8
Nvbowtie Registered User Join Date: Jul 2001 Location: Laughlin, Nv. USA Posts: 700	I guess I could just run the two lines out toward the body with a restricted opening so it could breath ? Maybe use some type of filter like hog hair ??? __________________ www.unlimited2u.com/chevy Bill 1980 Chevy C-10 Silverado 1988 Chevy Blazer Tahoe

09-20-2003, 07:51 AM	#9
77bowtie Registered User Join Date: Apr 2003 Location: New Mexico. Of all places for an Island boy. Posts: 180	I blocked off the 2 other lines (vent & return) and drilled an 1/8" hole in the center of my gas caps, to vent my tanks. Has worked fine for over 20 thou miles.



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