First post, need some help (1 Viewer)

[blake9480]

Hey guys, I just bought a 94 model and when I got home I had a pretty big fuel leak coming from the tank. I stopped for gas on the way home and noticed the gas cap was under a lot of pressure. I’m going to assume the pressure in the tank is what caused the fuel leak. I’m pretty sure I’ll need a new gas cap that will vent properly, I’m just wondering if I’ll need a new gas tank or if it can be repaired.

It needs some love and tlc but I got a good deal on it. Going to pull the heads and do the head gasket in the coming weeks. It has 300k so I have a couple things I want to do to it pretty quick

 

[blake9480]

Forgot to mention that I opened the gas cap and the gas leak stopped

 

[doc_random]

The gas cap should not vent. It seems likely that the problem is with the charcoal canister. It is located behind the battery, black, round with some small hoses going into the top, and one coming out of the bottom that may be hard to see. It's purpose to to let the expanding gas fumes go through the filter and be fed into the engine. There are spring loaded check balls in the top where the tubes go in that get gunked up and won't let the fumes in => pressure builds in the tank.
Search "charcoal" in this forum and you will get many hits.

 

[doc_random]

Forgot to mention that I opened the gas cap and the gas leak stopped

OEM Charcoal Canister Replacement

Well with the cruiser torn apart and waiting on several parts to finish up various projects. I decided to start one more project and follow up on a post from when I first bought the cruiser. Although not horribly bad I can tell the charcoal canister is clogged and intermittently causing to much...

forum.ih8mud.com

The above post has some pictures. The actual FZJ80 part is no longer available (NLA). There are some that are similar in size, and other posts with instructions on how to rebuild yours.
A google search of "vc120 vapor canister" has some options. This is what I went with a few years ago. Some minor work is needed to get it to fit.

The fuel pumps maintains pressure and the unused gas will loop back to the tank in the second fuel line. The gas will pick up heat as it travels through the engine bay. The gasoline gets hotter: in summer time (I am also in AZ), when driving slowly (more gas loops back), and with a low gas tank (less liquid gas to absorb the heat). Edit: ethanol blend (lower boiling point) also makes it worse.

If the hose pops off the charcoal cannister it will release fumes into the engine bay - very bad. Mine did not pop off but my cannister was hissing from the pressure.

 

[blake9480]

Do you think the gas tank needs attention being there was a pretty substantial leak?

 

[leonard_nemoy]

Do you think the gas tank needs attention being there was a pretty substantial leak?

You need to determine where the leak came from. We also need photos.

If you don't have emissions than unplug the hose from the charcoal canister and vent to atmosphere.

 

[jaymar]

Do you think the gas tank needs attention being there was a pretty substantial leak?

Do you know it's the tank and not a line or hose?

 

[BILT4ME]

Do you think the gas tank needs attention being there was a pretty substantial leak?

These are known to crack a gas tank on the top and onboard side where it contacts the bottom of the body.

If you only fill it to 3/4 tank you can drive it that way for over a year.

Search gas leak and you should find a thread about the crack.

You can buy used tanks from a couple folks on here and a new one is still available from Toyota for about $700.

Some have had minor success trying to weld or braze it.

Definitely need a new cap and charcoal canister.

Get the cap from Toyota and the VC120 or get the CC from Toyota for a 100 series and modify to fit.

 

[Funner]

Sounds like a field trip to the pet store is in order. I did this and have no issues.

Charcoal canister rebuild - 80 Series

80 Series Charcoal Canister rebuild. Bench grinder removes the seal cleanly. Wrap up is clean the valves, replace the old charcoal, button it up and reseal. You can weld it closed or use a good epoxy like JB weld. I will finish mine up later today with a little rattle can paint. The problem was...

forum.ih8mud.com

 

[RockShoes]

Sounds like a field trip to the pet store is in order. I did this and have no issues.

Charcoal canister rebuild - 80 Series

80 Series Charcoal Canister rebuild. Bench grinder removes the seal cleanly. Wrap up is clean the valves, replace the old charcoal, button it up and reseal. You can weld it closed or use a good epoxy like JB weld. I will finish mine up later today with a little rattle can paint. The problem was...

forum.ih8mud.com

Ditto. I just did the same and problem solved.

 

[blake9480]

Here’s pics of the gas tank, do I need a replacement?

 

[SmokingRocks]

I'd check the gasket on the fuel pump cover.

Get your FSM from the link in my description. It's your life line, save it on every device you have it'll help you do this.

 

[BILT4ME]

Here’s pics of the gas tank, do I need a replacement?

View attachment 3309183

View attachment 3309184

Looks like someone has already been in there at some point and coated the tank.

Maybe they tried to repair the tank and did a poor job and covered it with undercoating before they put it back.

Yes it looks like it's leaking from the typical place. Upper left of the picture.