Vented Gas Cap...Test
Thread Starter
Melting Slicks
Joined: Jan 2003
Posts: 2,713
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
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
