Originally Posted by thom4782

Thanks for the comments.

I was able to confirm the 1" to 1 1/2" grommet with the small in the center was the vent outlet. Finding the parts to make up the missing pieces of the vent line assembly was a bit more challenging. The L fitting and tube that I found in the trunk well fit the battery's front vent port and ran to the exit. To vent the rear battery port, I needed another L fitting, a T filling and about 3 feet of hose. With two stops at different parts stores, I had what I needed.

To make up the new assembly, I did the following:

• I removed the battery hold down bracket
• With the original tube's L fitting in the front battery vent port, I cut the original tube about 1" past the end of the battery
• Next, I attached the other end to the cut line to open end of the top of the T fitting and then inserted open end of the original line out through the grommet port
• Then to the remaining open end of the T, I attached the new line, ran it parallel along the side of the battery around the corner to the battery's rear vent port.
• I then cut new line to length while leaving a reasonable amount of slack.
• Next, I attached open end of the long tub to the new L fitting and inserted the L fitting into the battery's rear vent port
• Lastly, I reinstalled the battery hold down bracket.

To Graham's post, the fix described above is for those batteries where the blanking plugs are already removed / missing. Thanks for the tip on the AGM batteries.