So I replaced the aftermarket Duralast battery that was bad with this new Toyota TrueStart battery. They checked my VIN to make sure it was the right battery. However, this thing vent tube thing was in the old battery and it doesn't fit in the new one. Used car so I don't know the story. However, looking at it, it seems to be plugged with foam, so I don't know if it was doing much before. I am thinking maybe it is actually some kind of adapter already threaded on the end, and maybe the previous owner was supposed to remove the foam? Just about ready to try and remove the end of the tube, but wanted to post first for feedback before I damage this mystery hose.
I recently replaced my 2nd Toyota True Start OEM battery with an autozone DuraStart (AGM (Version for SmartKey) and did not encounter any problem with the vent tube going into the Duralast vent port near the 12V positive side. Mines a 2004 I think you will have to purchase the original vent tube for your year to make it complete.
Or just grab one out of another car It's actually you don't need the tube you need the fitting that goes on the end of the tube that is kind of barbed looks like an angle fitting for your plumbing pipes that's a half inch except this thing is like an eighth of an inch or the metric equal and this made the slide right into the hole in the place you're talking about on most AGM batteries now some of the newer AGM batteries don't even have a place for the vent tube they are unvented just like the later model hybrid battery doesn't have the vent rubbers on top of it no vent tube. I have that model battery in my car right now there's no vent tubes the old vent tube is just sitting there still sticking out of the floor.
So, I yanked the thing off the end, and I was able to stick the tube into the hole. I don't know if it's right, but the tube stays in there.
That will work fine One of these days if you're ever in a junkyard or see one of these cars in a towing lot Just look back there and you'll see a fitting just like the one you ripped off except it has little barbs on it on each end and it pushes into the end of the hose and pushes into the battery that has the hole One of these days you'll run into a battery that has no hole.