Vented Gas Cap...Test
Thread Starter
Melting Slicks
Joined: Jan 2003
Posts: 2,712
Likes: 31
From: Shreveport LA
LA Events Coordinator
Vented Gas Cap...Test
I purchased a new vented gas cap today for my 75. How does one test to make sure you have a "vented" cap. I was told to check it by putting the cap up to your mouth and sucking air (no jokes please)...then try blowing the air and you shouldn't be able to. Apparently there is a valve that lets air in but not air out....is this true?
Melting Slicks
Joined: May 2003
Posts: 2,387
Likes: 2
From: Meriden CT
suck on it... just like you said...(the hole on the underside)
I was wondering this same thing a few weeks back.
NHVette was kind enough to go suck on his in his garage for me.
it should also have "VENTED" stamped on the top...
I was wondering this same thing a few weeks back.
NHVette was kind enough to go suck on his in his garage for me.
it should also have "VENTED" stamped on the top...
Melting Slicks
Joined: Mar 2005
Posts: 2,838
Likes: 10
From: Austin TX
A GM vented cap will have a small hole (3/32"?) in the middle of the cap on the 'tank side' if that makes sense. Also, shake it,..you should hear the valve rattle a bit.
Last edited by 73, Dark Blue 454; Apr 26, 2006 at 10:05 AM.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
2027 Corvette vs The World: Every C8 vs Its Closest Competitor
Joe Kucinski
10 Most Common Corvette Problems of the Last 20 Years!
Joe Kucinski
5 MOST and 5 LEAST Popular Corvette Model Years in History!
Joe Kucinski
