I was talking about this comment - " only 2 days had passed since I'd put gas in, but not a half tank".  

Put a tub underneath and see if enough leaks out that it doesn't evaporate way.  That would be a lot.

Oh, ok.  I will go out right away to do it.  I had thought of doing that but dismissed it thinking it would evaporate.

I'll let you know.

Jai

 Not seeing it would be one of the clues to use. Next step would be to see when & where it does leak.

Do the tank drains have a copper washer like the oil pan?  Could be too tight or not tight enough, like the oil plugs do. Just a thought not knowing where it's coming from.

My 240 has a copper gasket/washer on the tank plug, I checked the parts book and it calls up a gasket for the 280's as well.  Could also be a leak at the fuel level sending unit, I had a bad o-ring on mine that leaked.

My '77 280 has the access cover with the o ring in the hatch, drops in from the top unlike my 240 which goes into the side of the tank. If her o ring has deteriorated it would smell of fuel inside the cabin. Good thought though as those o rings to go bad. 

I'm curious about the connections at the pump, more so of the high pressure out going hose, as mentioned earlier. If someone put a G3 filter on there a few months ago it could be there too.

She needs to have extra set of eyes looking while it's under pressure,  a camera would work,  in my opinion. 

Good luck Jai.

Site, Mark, and CanTechZ-

As to the copper washers, I have no idea.  But Steve, and then Tim and Steve, dropped the tank.  So most likely Steve, when he reads this, will be able to say.

I put a tub under the tank, like Zed suggested.  Will check it in a while to see if any gas dripping.  There was no gas on the fresh cardboard when I put the tub on it.

Thinking, could it be that the gas drips off only whilst she is warming up?  

Also, no gas odor in the cabin, with windows up.

Is the G3 filter the little one by the pump?  If so, it has been installed within the past few months.  I can check my repair log to get exact date later.

Would a fuel leak cause non starting or stalling?

Thank you CanTechZ, Mark, and Site for your thoughts!

Later,

Jai

The 1975/1976 Fuel Tanks have the Fuel Sending unit located half way up the side of the tank, not on top like the 77's and 78's. The earlier models are more prone to leaking from the sending unit O-Ring because it is below the level of the fuel when the Tank is over 50% full.

My sending unit was leaking around the 3 electrical wire connections that exit from the fuel sending unit. There are some small compressed O-Rings on the inner side of the sending unit. These O-Rings tend to dry out and crack with age. Unfortunately, it is next to impossible to replace them as they are Rivetted in place. Only leaked when tank was more than 3/4 full. Might be something to check.

The 1976 Fuel sending units are nearly impossible to find. I've been looking for NOS over a year.

What I did for a fix was to remove the sending unit from the tank, Then I thoroughly cleaned all around the terminals ( inside and out ) with a Dremel and Wire Brush. JB Weld makes an excellent product called " Water Weld " . This is about the only epoxy that will seal fuel tanks. Regular JB Weld will eventually dissolve in Gas or Diesel. This stuff will not. It is Gasoline, Diesel, Oil Hydraulic Fluid and Chemical resistant. It will cure under water... which, I guess , is why they call it " Water Weld ". After cleaning around connections I laid a bead of this stuff on the inside and outside of the connectors. This seems to have stopped the leak permanently. I can now fill the fuel tank up and no more leaks on the ground. I'm still looking for a replacement Fuel sending unit though. As with any Epoxies or Glues, proper surface preparation and claening is essential.

http://www.jbweld.com/products/waterweld-epoxy-putty

 

 

 

Jai,

before we get you too turned around. Let's try to pinpoint the leak, then we can come up with a good solution....

Thank you Patcon.  I have been writing notes on all that has been said.  

I just checked my maintenance log, and the little filter was installed on 8/15/15.  Long enough to get gunked up.  My son just left town today for a few days.  I had prepared a list of things for him to help me with, but it will have to wait now.  

Thank you Chickenman for your valuable information.

Ha!  Maybe that is it Chickenman.  I did not start smelling gas in the carport until I started fully filling the tank.

Wouldn't that be something...cannot fill over 3/4, and not let it get lower than 1/2 tank.   Hahaha, that's gonna be hard to do!

Jai

Edited January 21, 20169 yr by Redwing
new info

 At some point in time you're going to have to run her below half full to see if the problem arises again. As I recall, we never did pinpoint an internal tank leak as the definitive problem. Or is my memory getting as poor as my back?

Mark,

You are correct.  We decided to run her a while, not letting her get under the half tank.  That would be the first half of the proof.  Then I was to let her run low, to see if it happened again (per your suggestion).  That would be the 2nd half of the proof.  I have not done that half yet.  It will be easy enough to do tho, carrying my gas can to put gas in when she dies.  Waiting for the right time to do it.

Aching back from contortions whilst removing parts from PartiGirl?  Ouch!!!

We got some sleet today, but are forcast for accumulating snow starting Friday.  I'll get a ride to church.  I don't think they salt these country roads, but I'm going to call and ask to make sure.

Jai