Eddie, It is not unusual for older tanks to build a bit of pressure, maybe you would hear a little "hissss" when you open the cap. Most Pre-1971 (1970 California) caps were not pressurized, so sometimes a clogged vent hole could cause the tank to create a vacuum, sometimes even cutting off gas to the engine. If it is not a pressurized system replace the cap. You should be able to get a vented cap at any "good" parts store. If the tank is pressurized some of them push fumes into a charcoal canister if that model has one, or to the evaporative control box. In this kind of system it would be normal to hear a fairly heavy pressure release, especially on hot days. If the system is pressurized you could have a pressure release valve I believe off the charcoal canister, control box, or in the cap, and if you have an unusually high pressure buildup you may have to again replace the cap or valve. The way I understand it vapors from the tank or carburetor bowl vent are vented to the canister which absorbs the fumes to be later drawn into the engine to be burned. I know in Houston this won't be a problem but in areas of the country where there are elevation changes, such as in the mountains you could experience a very high pressure in the tank after rapid elevation changes. Not all states test evaporative control systems, or even gas caps as part of annual inspections. You may want to resolve this soon as there have been cases where too much pressure or vacuum buildup in a tank has split the seams. That might just ruin your day. As always just my .02 cents worth and not to be taken as gospel. Sheldon Aubut Houlton WI USA http://www.sheldonaubut.com Date: Thu, 29 Oct 2009 13:45:05 -0500 From: "Eddie Stakes" <eddiestakes@xxxxxxxxxxxxxxxxxxxx> To: <baadassGremlins@xxxxxxxxxxxxxxx>, <amc-list@xxxxxxxxxxxx>, <iowaeagle@xxxxxxxxxxxxxxxx> Subject: [AMC-list] amc eagle vented gas caps Message-ID: <353F87F613024803B9D700FFFCE20525@piageedc1iqa5q> Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=original Is there a gas cap made for AMC Eagle that is Vented? For whatever reason, sometimes, especially on hot days, you can take the gas cap off one of our Eagles and it literally will blow off in your hand from pressure. I think it probably has to do with oxygenated gas that is used in Houston. A report on one of the local television stations a few weeks ago was talking about the best time to buy gasoline at stations, which is at night, when temps cooler, as you get what you pay for, as if you fill up during day, you lose some of the gas to vaporazion. Didn't know that, but gan tell you the gas is bubbly around here foe years and many places use ethanol mix in gas which (to me) is hardly flammable. _______________________________________________ AMC-list mailing list AMC-list@xxxxxxxxxxxx http://list.amc-list.com/listinfo.cgi/amc-list-amc-list.com