Are liquid check valves rebuildable? - Page 2 -
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back > Models > Jeep CJ Forum > Are liquid check valves rebuildable?

Introducing MONSTALINER™ UV Permanent DIY Roll On Bed LineWeekend sale!! Our dual battery tray on sale $199FS: 2007-2013 Jeep Wrangler "HALO" Angel Eye Kit

Unread 01-07-2014, 05:11 PM   #16
Registered User
1976 CJ5 
Join Date: Feb 2009
Location: Vallejo, CA
Posts: 685
Originally Posted by DirtyCJ7 View Post
Thanks all,
I replaced the fill neck and cap. in Cali they pressurize the system to about 5psi and it needs to hold. So the LCV is needed to hold back the pressure so it dose not vent.
Actually, that's not quite how it works. The way they should be testing the evap system is to pinch closed the vapor line up at the charcoal canister (where it is easily accessible). The LCV won't hold back pressure unless it is closed (gas has filled it enough to lift the float to the closed position). It isn't a vapor check valve, just liquid. So they close the line in the front to pressure test via the connector that fits over the filler hole. Besides something like a bad o-ring on the valve (and possibly the roll-over valve as well) you probably also want to look at the condition of your hoses. Mine were shot and replacing them solved my leak test fail. Also, pressurizing my system was actually forcing fuel out through the fuel line (which was also cracked).

To make sure mine passed after fixing things, I made my own pressure testing setup before taking it in for the re-test:

Jeffrey Charles
JeffreyCharles is offline   Reply With Quote Quick reply to this message

Quick Reply

Register Now

In order to be able to post messages on the forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.
Confirm Password:
Email Address
Please enter a valid e-mail address for yourself.
Note: All free e-mails have been banned due to mis-use. (Yahoo, Gmail, Hotmail, etc.)
Don't have a non-free e-mail address? Click here for a solution: Manual Account Creation
Email Address:


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Thread Tools

Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. is not in any way associated with Jeep or the Chrysler Corp.