Filler neck leak around plastic collar. Please help!

Hello 1st gen taco owners I was hoping you could help me. I have gas fumes coming out from behind this plastic collar piece at the top of the filler neck right below where the gas cap sits. Mine is loose and I would imagine it should be tight if it’s going to hold gas vapor. Has anyone else had this problem? It’s not the gas cap and I don’t see a way to remove the plastic piece to possibly see what’s going on underneath. Any advice?

 

Ideally it like to take it apart but I don’t think I can with out bending or breaking something. Yea somebody on the taco Reddit forum suggested the same thing. I thought about that too but didn’t think whatever I used would be strong enough to hold the pressure. He said to use a polyurethane based sealant.

 

I'd consider trying JB Weld Tank Weld. Other than that probably need to replace the whole filler neck.

I JB welded a radiator once and it held up to the heat/pressure of the cooling system so I imagine it'd do OK in the EVAP system

 

Sometimes it's easy to over think things.

 

Isnt the filler neck made on the Tank Itself?

 

Your Evap system if working correct should be drawing out the fumes.

What do you have to lose it vents now . Put on some sealer and call it good.

 

Thank you all for responding but I just realized something laying here in bed. The filler neck isn’t leaking fumes. The plastic piece is where the fumes are vented to. The tube that’s connected to the plastic piece leads back to the canister. I think maybe something is stuck open causing the fumes to vent more than they should. I wonder what would happen if I just cap the rubber hose connected to it.

 

Tripping any Evap codes??

In the old days the canister vented to the air now it in drawn into the intake.

 

That’s the weird thing it’s not giving me any evap codes and yea why are the fumes venting out of this thing?

 

I'd probably be inclined to replace that over trying to repair, considering you have to take the bed off to get full access to the part. There are a couple of aftermarket options around $60, OEM is double that. Also worth taking a look at your gas tank gaskets while you have it exposed, when I was having EVAP issues that's where my gas fumes were coming from. Your tank looks like it's in pretty good shape though, so your gaskets may be alright.

If you cap that hose I'd expect you'd get an EVAP check engine light. I believe there is a vent valve on the charcoal canister, it's possible that it has failed.

 

These last pictures are your truck ??

Did you replace those worm gear clamps ? Someone has been in there before.

 

mine has those types of clamps from the factory.

 

No dont cap that. If they wanted it capped they wouldnt have put it there.

 

Interesting must have been a production change my 2000 has the spring clips .

Maybe they ran out .

 

Hey yea I notice that today and thought the same thing but someone else said that’s how it came from the factory, go figure ‍♂️

 

Yea I agree. I spent the day trouble shooting the system (I have the factory service manuals for my year taco). I found that one of the valves on the canister was a little stuck (see picture). I had read last night that you can “dry it out” by putting compressed air through it. I took the canister off and ran 50psi through it for about an hour. The smell of gas fumes was significantly less afterwards. I also unstuck the valve. If that doesn’t work I suspect the canister is to saturated and I’d have to get a new one

 

While I was in bed last night I realized that those fumes leaking out from behind the plastic collar aren’t coming from the inside of the filler cap they’re coming from the air drain hose coming from the canister. Seems like the canister vents to the atmosphere through this hose which I find kinda weird. I removed the canister and checked it out. One of the valves attached to it was kinda stuck (see pic) so I got it unstuck. I put 50psi through it for about an hour to “dry it out” which I read you could do. The smell of fumes was significantly less after that. And yes I’m also changing those gaskets as well. They’re still good but for how much longer right? Tomorrow I’ll turn it on and see if what I did helped, if not I’ll have to buy another canister ‍♂️

 

here is the part number for those worm gear clamps. If your truck doesn’t have them it’s because someone else removed them. All tacos came with them on the filler neck over flow pipe.

 

Ok thank you sounds good. It pouring outside right now. I’ll start working on the ole battle ax once it dries up.

 

Good deal I wish it was just raining here.
It’s negative 9 with blowing snow here.
They say the wind chill is negative 37 but, below 5 it all feels the same.