vented gas tank - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**67sss** · 02-25-2004, 01:34 AM

where do theses go? is this a CA tank or was that normal in 71?

Longhorn Man · 02-25-2004, 01:58 AM

Up the pillar and looped together.
normal on all 71/72 trucks.

72c10step · 02-25-2004, 11:00 AM

Not to hijack, but if that was removed and replaced with a short loop of hose, could it cause a gas smell or gas fumes to leak into the cab? Just trying to get rid of the fumes in my cab.

JimKshortstep4x4 · 02-25-2004, 11:07 AM

There were variations in the 71-2's. The AC cabs, (not sure if all were this way), had a sending unit with two lines on it and no
vent line on the side as the picture shows. On the side vents, like the picture shows the line looped up into the cab, down through the floor and was routed to the carbon canister in the front.

Jim

jhow66 · 02-25-2004, 12:34 PM

72c10step do you smell it more after putting in gas? Your gas neck hose is probably leaking-had same problem on my 65 GMC-fixed it with new hose on fiiler neck.

**Classic Heartbeat** · 02-25-2004, 01:49 PM

The 67-72 tanks do not have filler neck hoses. The 71-72s with eec had a filler neck vent hose, but that is it. If he is smelling gas the problem is likely to be the "O" ring that seals the sending unit to the tank. Other problems are gas leaking out of the tank when you make a right turn, then following the filler neck into the cab, or the tank vent lines pictured leaking fumes. If the gas is following the filler neck after leaking on right turns, then he could try replacing the gas cap and the filler neck grommet. WES www.ClassicHeartbeat.com

72c10step · 02-25-2004, 05:06 PM

Should I go with a sealed cap, or vented? I know its a 72, so they normally had sealed (I think), but with all the emissions stuff removed, shouldn't it be vented instead?

**Classic Heartbeat** · 02-25-2004, 06:21 PM

I would go to a vented cap. I use vented caps on all my tanks. WES www.ClassicHeartbeat.com

72c10step · 02-25-2004, 09:02 PM

What years are the vented cap from, 67-70?

william 70 c/20 · 02-25-2004, 09:28 PM

i have a vented cap and a vaccuum develops as i drive..is this sucking normal?

02-25-2004, 01:34 AM	#1
67sss Registered User Join Date: Nov 2002 Location: Mt. Vernon, WA.. Posts: 2,325	vented gas tank where do theses go? is this a CA tank or was that normal in 71? Attached Images

02-25-2004, 11:00 AM	#3
72c10step WHYBYNU when old will do? Join Date: Jul 2003 Location: Loudon, NH Posts: 876	Not to hijack, but if that was removed and replaced with a short loop of hose, could it cause a gas smell or gas fumes to leak into the cab? Just trying to get rid of the fumes in my cab. __________________ -72 Chevy C10 Stepside -2002 Chevy Silverado 2500HD 4x4 -1984 Jeep CJ7 -1995 Polaris XCR600 Custom -2003 Honda 300ex

02-25-2004, 12:34 PM	#5
jhow66 Registered User Join Date: Jun 2002 Location: Knoxville Tenn. Posts: 3,058	72c10step do you smell it more after putting in gas? Your gas neck hose is probably leaking-had same problem on my 65 GMC-fixed it with new hose on fiiler neck. __________________ 56 Chevy Bel-Air 2dr. HT (purchased new) 71 Chevy Cheyenne SWB PU (502HO) 65 GMC short bed step--work in progress and my gofer

02-25-2004, 01:49 PM	#6
Classic Heartbeat Project Junkie! Fishing Poor!! Join Date: Dec 1999 Location: Olympia,Wa. 98512 Posts: 10,766	The 67-72 tanks do not have filler neck hoses. The 71-72s with eec had a filler neck vent hose, but that is it. If he is smelling gas the problem is likely to be the "O" ring that seals the sending unit to the tank. Other problems are gas leaking out of the tank when you make a right turn, then following the filler neck into the cab, or the tank vent lines pictured leaking fumes. If the gas is following the filler neck after leaking on right turns, then he could try replacing the gas cap and the filler neck grommet. WES www.ClassicHeartbeat.com __________________ On-line catolog Classic Heartbeat Pickup Parts WEHEPP@comcast.net Call us Toll Free (888) 338-2502 Like Us on Facebook No appointment necessary. 72 BB Chevy Custom Deluxe / Custom Camper 67 I-6 (Soon to be 5.7 LS1) Panel 68 BB Chevy Short Bed 72 6.0 LQ9 Short Bed Chevy 4X4 Olympia's fastest growing truck parts supplier. Olympia's home for Wayward Chevys

02-25-2004, 05:06 PM	#7
72c10step WHYBYNU when old will do? Join Date: Jul 2003 Location: Loudon, NH Posts: 876	Should I go with a sealed cap, or vented? I know its a 72, so they normally had sealed (I think), but with all the emissions stuff removed, shouldn't it be vented instead? __________________ -72 Chevy C10 Stepside -2002 Chevy Silverado 2500HD 4x4 -1984 Jeep CJ7 -1995 Polaris XCR600 Custom -2003 Honda 300ex

02-25-2004, 01:58 AM	#2
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	Up the pillar and looped together. normal on all 71/72 trucks.

02-25-2004, 11:07 AM	#4
JimKshortstep4x4 Senior Member Join Date: Jul 2001 Location: Muskegon,MI,USA Posts: 6,026	There were variations in the 71-2's. The AC cabs, (not sure if all were this way), had a sending unit with two lines on it and no vent line on the side as the picture shows. On the side vents, like the picture shows the line looped up into the cab, down through the floor and was routed to the carbon canister in the front. Jim

02-25-2004, 06:21 PM	#8
Classic Heartbeat Project Junkie! Fishing Poor!! Join Date: Dec 1999 Location: Olympia,Wa. 98512 Posts: 10,766	I would go to a vented cap. I use vented caps on all my tanks. WES www.ClassicHeartbeat.com __________________ On-line catolog Classic Heartbeat Pickup Parts WEHEPP@comcast.net Call us Toll Free (888) 338-2502 Like Us on Facebook No appointment necessary. 72 BB Chevy Custom Deluxe / Custom Camper 67 I-6 (Soon to be 5.7 LS1) Panel 68 BB Chevy Short Bed 72 6.0 LQ9 Short Bed Chevy 4X4 Olympia's fastest growing truck parts supplier. Olympia's home for Wayward Chevys

02-25-2004, 09:02 PM	#9
72c10step WHYBYNU when old will do? Join Date: Jul 2003 Location: Loudon, NH Posts: 876	What years are the vented cap from, 67-70? __________________ -72 Chevy C10 Stepside -2002 Chevy Silverado 2500HD 4x4 -1984 Jeep CJ7 -1995 Polaris XCR600 Custom -2003 Honda 300ex

02-25-2004, 09:28 PM	#10
william 70 c/20 Registered User Join Date: Jan 2004 Location: LV,NV Posts: 169	i have a vented cap and a vaccuum develops as i drive..is this sucking normal?



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