Help with 80 fuel filler neck and tank (1 Viewer)

[powdahbonz]

I’m struggling with the tank belt bolts and can’t free them. I’m 99% sure that my leak is from the fuel fill neck and wondering if I can’t drop the tank, has anyone pulled the neck without dropping the tank? Not sure what is the path of least resistance. Pours from jerry cans do not show the leak however at the pump, well, let’s say my local stations know me and won’t let me fill. Also can’t seem to find a new fuel fill neck so if anyone has ideas, please let me know.

 

[inkpot]

Does it leak only when tank is close to full? Crack on top of tank is VERY common. Many threads on here about leaky tank. IIRC, you have to lift body away from frame to pull filler tube.

 

[ZeGerman]

the rear of the wheel well by the filler neck has a plastic cover. Couple of screws and that cover comes right off exposing the entire filler neck to the rubber hose connections. Start there first and see. If you're lucky the problem is up there. Other than that it will get quite hectic for you.

 

[slow95z]

The trick is to cut the neck in half. You do it right near the frame and then join it back with some coupling and hose clamps. It cannot be removed with the body on the truck. You must unbolt it and lift it up several inches.

 

[Sc0-]

Not sure if I understand, the filler neck is connected to the tank by hoses and hose clamps. It's a solid metal structure that will need the body lifted up a bit off the frame to be removed. Possible to remove but far from easy.

A more common issue is a fuel tank crack on top front corner where the E-brake cable is at. A few threads are on here that talk about that...

 

[namsag]

Holy Cow is having to lift the body off the frame only if you can't get the gas tank out, or do you have to do that even if you can??

 

[powdahbonz]

No, it’s leaking when filling at the pump. Put 10 gallons in via jerry cans didn’t spill a drop to see where the leak is coming from. So leads me to believe it’s the fuel filler neck because pump fuel, according to my wife is quick to weep and spill at the pump. Can’t duplicate by pouring from a can. I thought dropping the tank would give me a look to see if the tank is the issue or the neck. I have hit the bolts with plenty of pb blaster and freeze off but no joy. Going to try again tomorrow and look at the neck to see what I can do but cutting isn’t a safe option with vapors and tank attached.

 

[91wilc]

It’s been a few years since I did this but I definelty replaced the fuel filler neck on my 91 without too much trouble. I got a new one from Beno at Toyota and it was an hour job tops. Not a master machanic by any means. Just don’t understand what the people who are talking about lifting the Body off the frame are talking about? Have they had to do this to Tackle this issue?

 

[91wilc]

Upon rereading my issue was a rubber hose. Is it possible that this is where your leak is?

 

[powdahbonz]

I think the leak is just over the rear axle, where the fuel hose and vent line are touching together after the bracket. When I was trying to remove the bracket, both bolts snapped so that sucks. But there was a rainstorm of rust dropping on me. It seems likely this is where the issue is.

 

[medikateme]

The filler neck is prone to corroding at the support bracket roughly just in front of the rear axle. Look for a white residue on the underside of line/metal pipe. Also the pipe will appear "cleaner" than the surrounding metal surface where the leak runs down the outside of the pipe. Will be subtle but visible. If you can, get your phone camera lens up in there with flash on and snap pics of the top side of the pipe. Could be occurring where the vent line and filler pipe meet. Hard to see when laying on your back underneath the truck. Here is a pic to give you an idea.

 

[medikateme]

If you keep filling with the jerry cans my guess is that you will find the leak. Filling the tank until the pump shuts off at the station is loading that filler neck close to the top which is why you likely are seeing the leak at the station. That and the pressure with which the fuel is entering the filler neck is likely forcing it out the leak point. Once the fuel level drops below the neck the leak stops.

 

[Wompom]

I've had the same problem intermittently. My theory is a bad charcoal canister. Mine is completely clogged, so my thought is that the pump fills the tank fast enough to cause some sort of pressure in the tank and air cant vent as its being filled, ends up burping itself out.
OR i have a hole in my filler neck. Will know once i try to fix my CC. I've had 3 overflows out of 20 tanks of fuel since rebuild so not sure why it happens only sometimes.

 

[powdahbonz]

So the leak was where the air and fuel were welded/linked together. If you look to the right of the screwdriver, hole is roughly 1” long with about a 3-4” line where the hole is leading. Tried to remove the filler neck today, can’t Free either line from the tank. If I drop the tank, I have to break the tank strap mounts because the nuts wont release. Very frustrated to see what needs to be fixed but all of the options aren’t good. I’ve been told that any JB weld or similar permatex compound won’t adhere due to rust. If I could sleeve the pipe with another fuel hose that would work. But I still need to get it down on the ground to release the fuel filler. Never mind the fact that I can’t get a replacement..I need a beer

 

[Wompom]

ouf. Tough break. Guess i need to check that spot on mine too. could you sleeve it and use worm clamps of some kind temporarily?

 

[medikateme]

IIRC Cruiserparts.net was getting roughly $250 for a used neck and 2-2.5 labor hours for install. Don't quote me on that but it may be worth your while to check. I do not have any direct experience with their work or their parts. Nice Fall drive from Kennebunk to Sullivan, NH though

 

[medikateme]

Replacing fuel tank filler neck

 

[Red Merle]

Just did the whole jalopy. Don't cut the filler neck if you can avoid it. It needs to bolt up to be able to hold it in place for filling.

If you have any questions, feel free to ask in this thread or just keep it in that thread so the next guy can find it all in the same place. The body lift is no big deal if you prep your fasteners.

Prepping and installing a new gas tank, filler neck and skid plate.

 

[medikateme]

Hey Red, I saw your writeup. Great one. Did you need to jack the body in the front as well or just the rear? If solely the rear how many body-mounting nuts did you need to undo?

 

[Red Merle]

Hey Red, I saw your writeup. Great one. Did you need to jack the body in the front as well or just the rear? If solely the rear how many body-mounting nuts did you need to undo?

I removed the fasteners from the first three sets if you are going from the rear, forward. I didn't wreck or break any of them and the body was lifted off before any of them lost sight of the hole in the frame that they go through, if that makes sense. I used heat on all of them, but I only did that once I had the old tank out and away from the truck.

I did buy an extra set of the rear most ones, but I wasn't able to get those in because it involved another project of getting the trailer hitch off, and that fell outside the scope of work that I had scheduled and planned for with the gas tank project. Those are going in soon though. I got the hitch off without breaking anything and the rear bumper is getting re-outfitted with rust free and protected sheet metal that I picked up on a pallet deal.