Gas cap leakage - The 1947 - Present Chevrolet & GMC Truck Message Board Network

billtoothaker · 02-17-2004, 05:57 PM

I have a 72 Chevy and have tried a couple of different caps but if I fill the tank it leaks, Is there something I am Missing?

oleblue72 · 02-17-2004, 06:05 PM

I had to replace the gasket on my original cap, it was dry rotted, that fixed my problem.

tommie · 02-17-2004, 06:52 PM

where did you get a gasket from?

70c10 · 02-17-2004, 07:05 PM

My new gas cap has always leaked.

walker · 02-17-2004, 08:19 PM

I have a brand spankin' new cap that leaks under hard right turns when full. I would like to put in one of those baffles that are in the necks on fillers in newer cars.

gotmud · 02-17-2004, 08:24 PM

Surely there is a manufacture out there that has a billet cap with a chevy logo and a lock that is guaranteed not to leak....
My paint has streaks so much gas has leaked...ugh...
Lets hear some solutions from the creative side of the board....my solutions so far have been shop rags in the bed...but that seems to be a fire hazard.
Deland Im in for next week!

oldsub86 · 02-17-2004, 09:07 PM

Someone took my original Blue - matched the truck colour, gas cap and I had to buy an aftermarket one at a local store. It leaked and was difficult to put on and take off. I took out the original gasket and made one out of a piece of inner tube. It has been fine and has not leaked in several years.

I think you also need to be a bit careful not to totally fill with cold fuel from an underground tank on a warm day. The fuel will expand enough to leak out around the cap even when the truck is not moving. I wonder if you get enough expansion of the fuel to improve your miles per gallon calculations?

lewi · 02-17-2004, 09:08 PM

I went through the same thing and the best solution was to get rid of the tank. Go with the saddle tanks or between the rails type that takes the place of the spare. I got pretty tired of smelling gas in the cab anyhow.

Alvin · 02-17-2004, 09:34 PM

I had the same problem with mine. I picked up a cheap-o at AutoZone ('cause Jesse James told me to

) and the tank never leaked...through the cap anyways. Here's what the side of my truck looked like when I bought it.

Dean · 02-17-2004, 10:40 PM

Make sure you have the right year cap also. I believe the 67-70 cap is different, but I could be wrong. I don't have any catalogs in front of me to verify this. I had this problem once though.

SideStepper · 02-17-2004, 11:11 PM

Gas leaking from the cap on our old trucks (1955-72) is a common problem. If you looking for a good non-locking cap, I recommend Nappa. Ask for cap #703-1220, sells for about $10-$15.
Another thought, check the gas tank neck surface, where it seals up against the cap........... before you put the new one on. Look for nicks or dents, make sure it is flat & smooth.

02-17-2004, 05:57 PM	#1
billtoothaker Junior Member Join Date: Feb 2004 Location: Rochester, NH Posts: 92	Gas cap leakage I have a 72 Chevy and have tried a couple of different caps but if I fill the tank it leaks, Is there something I am Missing? __________________ Bill Toothaker 72 K20 FSLB 63K FS:86 Mercedes 560SL 63 Ford F100 51 Willy's Jeep station wagon w/64 289 Studebaker 68 Honda SL90 1500 miles Chevy 6 cyl street rod 2011 Nissan Murano cross cabriolet Cabins for Rent Lake Winnipasaukee, NH

02-17-2004, 06:05 PM	#2
oleblue72 No, U Da Man! Join Date: Mar 2001 Location: Southaven, MS Posts: 284	I had to replace the gasket on my original cap, it was dry rotted, that fixed my problem. __________________ (sold ole blue 1972) 1997 Dodge 1500 5.9L 1996 Saturn SL2 1.9L 2002 Mitsubishi Montero 3.0L 2005 Ford Escape 3.0L *1967 Olds Vista Cruiser 330-320HP*

02-17-2004, 07:05 PM	#4
70c10 67-72 Addict! Join Date: Feb 2002 Location: The TAX State! Posts: 7,857	My new gas cap has always leaked. __________________ Jim 1970 C/10 Fleetside w/Ghost Flames Lowered 4.5" front and 4" rear (Raked) 355/350 Turbo w/shift kit 10" Redneck Performance Verter w/2500 stall Hooker Super Comps part#2808-1 Performer RPM Air-Gap 12 Bolt w/3:73 gears- Eaton Posi Comp Cams XE262 with 1.6 Crane Energizers, Road Demon 625 and Brodix IK 180 heads

02-17-2004, 08:19 PM	#5
walker Registered User Join Date: Jul 2003 Location: north of Phx AZ about 30 miles Posts: 698	I have a brand spankin' new cap that leaks under hard right turns when full. I would like to put in one of those baffles that are in the necks on fillers in newer cars. __________________ Andy,Phx AZ '67 C-10 (Ahhh, done at last. Well there is that disk front end I want to put in and...) "23 C-Cab-sold '48 Ford 8N tractor(still working) '67 Scout(Now on the road) '70 MG B.-sold

02-17-2004, 08:24 PM	#6
gotmud Registered User Join Date: Oct 2003 Location: Cumming, Ga Posts: 234	Surely there is a manufacture out there that has a billet cap with a chevy logo and a lock that is guaranteed not to leak.... My paint has streaks so much gas has leaked...ugh... Lets hear some solutions from the creative side of the board....my solutions so far have been shop rags in the bed...but that seems to be a fire hazard. Deland Im in for next week! __________________ Glenn Cumming, Ga (68 C/10 Fleetside LWB 307 (64 C/10 Fleetside Shorty Custom 350, with 73 donor parts aplenty) (2001 Porsche Boxster S - 168 MPH of fun) (2005 Chevy Avalanche Z71 1500)

02-17-2004, 06:52 PM	#3
tommie 97' Tahoe 2dr/2wd Join Date: Jul 2002 Location: Huffman,TX Posts: 1,168	where did you get a gasket from?

02-17-2004, 09:07 PM	#7
oldsub86 Registered User Join Date: Dec 2002 Location: Canada Posts: 695	Someone took my original Blue - matched the truck colour, gas cap and I had to buy an aftermarket one at a local store. It leaked and was difficult to put on and take off. I took out the original gasket and made one out of a piece of inner tube. It has been fine and has not leaked in several years. I think you also need to be a bit careful not to totally fill with cold fuel from an underground tank on a warm day. The fuel will expand enough to leak out around the cap even when the truck is not moving. I wonder if you get enough expansion of the fuel to improve your miles per gallon calculations? __________________ 1968 Chevy - 292 with a powerglide

02-17-2004, 09:08 PM	#8
lewi Registered User Join Date: Nov 2002 Location: Redding California Posts: 223	I went through the same thing and the best solution was to get rid of the tank. Go with the saddle tanks or between the rails type that takes the place of the spare. I got pretty tired of smelling gas in the cab anyhow. __________________ 1971 Chevy Cheyenne 383/350 LWB 2wd Built to use, and look good.

02-17-2004, 09:34 PM	#9
Alvin Never Done? Join Date: May 2000 Location: Ohio Posts: 1,435	I had the same problem with mine. I picked up a cheap-o at AutoZone ('cause Jesse James told me to ) and the tank never leaked...through the cap anyways. Here's what the side of my truck looked like when I bought it. Attached Images __________________ Ethel - The Legend Continues... Ethel has been sold.

02-17-2004, 10:40 PM	#10
Dean Senior Member Join Date: Jan 2000 Location: Cincinnati, Ohio Posts: 1,492	Make sure you have the right year cap also. I believe the 67-70 cap is different, but I could be wrong. I don't have any catalogs in front of me to verify this. I had this problem once though.

02-17-2004, 11:11 PM	#11
SideStepper Registered User Join Date: Jun 2002 Location: Southern California U.S.A. Posts: 275	Gas leaking from the cap on our old trucks (1955-72) is a common problem. If you looking for a good non-locking cap, I recommend Nappa. Ask for cap #703-1220, sells for about $10-$15. Another thought, check the gas tank neck surface, where it seals up against the cap........... before you put the new one on. Look for nicks or dents, make sure it is flat & smooth.



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