4runner fuel leak help

[Devilmans Hand]

Hello everyone

I just noticed a fuel leak on my 1986 1st gen 4runner tonight.
Currently the fuel tank is nearly empty from normal driving mileage.

The one-second drip appears to originate under the fuel filler hose and above the bottom hard line that runs on the passenger side of the frame. The leak does not appear to come from the large filler hose.
I noticed the drip at the gas station, and thus did not fuel up so the tank is near empty and the leak comes from a relatively high location in relation to the height of the tank as it sits on the body.

The drip increased rate after I shut off the engine, so I suspect the leak is in the return line.

If you are familiar with the fuel lines on the 4runner they are inaccessible without pulling the tank.

Right now my 4runner is pulling sole Daily Driving Duty, but I can borrow a car for the next two days before I have a day off Sunday to investigate further.

I have to fix this no later than Sunday night.

Does anyone have any suggestions or advice on where this leak may originate, how hard those parts may be to replace, and how difficult it is to drop the fuel tank in order to access this location?

Sam

 

[Von Hayek]

This sounds similar to the leak I had on the 62:

- leaking coming from the filler neck area that was hard to see
- leaked horribly when I filled up, but went away soon after I burned some fuel off

What it turned out to be was a clogged charcoal canister that wouldn't allow the pressure in the tank to equalize. After the tank was filled with cold gas, the pressure increased as it warmed and forced gas past the fuel cap. It wasn't obvious because the gasket between the filler neck and the body was shot and would go right past it.

I'm not saying that this is your problem, but certainly keep in the back of your mind.

 

[OTRAMM]

There's a trap door under the rear seat to get at the fuel lines. It's probably a rusted hard line on the fuel pump hanger. You could still get them from Toyota last I checked. They aren't cheap though.

 

[Devilmans Hand]

There's a trap door under the rear seat to get at the fuel lines. It's probably a rusted hard line on the fuel pump hanger. You could still get them from Toyota last I checked. They aren't cheap though.

Thanks for the tip. That's what I'm thinking it is after 300k and heavy use of salt.
I'll look under there Sunday morning and see what I can find.
Likely I will not be able to source the lines on Sunday. Is there a polymer product, like JB weld that might temporarily stop the leak if I slather it on?

 

[OTRAMM]

The few I've done were so brittle that just touching made them break the rest of the way off. The last one I did was on a mid nineties truck and the hanger assembly was special order. I think it took a few days to show up since it came from the West coast. I re flared on of them on my 4Runner to be able to use stainless braided line. But mine hard lines were good and it was still a pain to get them to flare.

 

[Devilmans Hand]

Has anyone used swagelok fittings on efi hard fuel line? I'm thinking this will be the easiest good option for a spliced fix.

 

[OTRAMM]

I've used the Russel compression fitting to AN fitting adapters on a 4runner fuel line. That's what I originally had adapting the pump for my fuel cell to the factory supply line. I think I used a 3/8". I was never really happy with the way it fit so I flared the line to accept the AN tube nut. The compression fitting never leaked but I was always leery of it.

 

[Devilmans Hand]

Word. I'm thinking these things would be good to keep in the trail parts box too.