Exciting gasoline fill-up

[Mark L]

Yesterday (February 17, 2024) I attended the North Puget Sound Chapter SDC monthly meeting/lunch.  I drove my '63 Avanti R1.  After the meeting, I drove to a local farm/feed supply to buy ethanol-free gas.  In the 11 months I've owned the car, I've put gas in several times, but never actually topped off the tank.  Yesterday, I decided to top it off to make sure the gas gauge is working full-sweep.  It turned out to be an exciting/frustrating fuel stop.

While I was pumping, several people came by and mentioned something was leaking at the front under the engine.  It has leaked a little anti-freeze in the past.  Without actually being able to see while I was pumping the gas, that's what I assumed it was.  When I finished pumping, I went to the front and found a strong, steady stream of gasoline streaming down near the power steering pump and fuel pump.

I opened the hood, and saw gas coming from a short hose that looked like it was disconnected next to the fuel pump.  The end of the hose still had a hose clamp on it.  The supply to the pump was connected, so I assumed it was the return line to the tank.  I was able to start the car and move it away from the pumps, and it never hesitated, so I knew the supply line was not sucking air.

I got the car off to the side, but gas continued to stream out.  The store had one bag of oil-dry at the pumps, and I used all of that.  The employees went to find several more bags, which we used.  I initially tried to fold the short hose over, but it was so dry-rotted it just snapped in half.

They had no tools, but there was a hardware store across the street.  I went there and quickly bought a ratchet set, some fuel hose, and some clamps. I then removed the old rotten hose that was disconnected and replaced it with a much longer hose, and I folded the end over and clamped it off.

I ended up losing almost as much gas as I purchased.

I called my wife to come to the station so she could follow me home.  In the photograph she took, you can see the stain on the pavement I left behind when I moved the car from the pumps to the side of the parking lot.  I called the county's non-emergency number and requested a fire truck come down to the store to stand by, just in case something worse happened.  In the photograph, I'm laying in the mess under the front bumper with gas running down my left arm to my armpit.  The store employees are to the right, keeping the spill contained until I could get it stopped, and three of the fire engine crew are checking out my Avanti.

The leak stopped on its own before I capped off the open line, so I suspect enough gas leaked out to stop the flow.  I was able to drive home with no other problems.  Without thoroughly checking, I suspect that either the hose just came off the return fitting at the outlet side of the fuel pump, someone forgot to install the hose the last time the fuel pump was changed, or the fitting was changed and there's no place for the hose to connect any longer.  When I topped off the tank, the gas must have overflowed down the return line back to the engine. 

Now I have some fuel system maintenance to perform.  To be safe, I left the car parked on my driveway until I can get the issue resolved.

 

Edited February 21 by Mark L

[aardvark]

Nothing like roadside repairs to mess up a perfectly good day. Glad no fire or other disaster took place.

Once I was running down I-94 from Detroit to Chicago in the middle of the night.. The car severely overheated.. I pulled off at an exit in the middle of nowhere. The only thing at that exit was a Strip Club. I diagnosed the car's thermostat was not opening. Luckily I had tools and removed it but what about water to refill?

I suggested to the Wife i needed to go in the Club to get water...''''I'll stick to Business!!'''''' NO WAY '''', She Cried!..  So, after looking around for a water source  in the middle of the night,  I was down at the ditch filling up 2 styrofoam cups at a time of ditch water to get the car back on the road. It took a solid gallon or so and about 45 minutes collecting it..

Would have been easier to go into the Strip Club... it was a real skank place and really not tempting at all.... but... we got home.

[Mel]

As you know, the gas tank on these cars sits on a ledge behind the back seat and, if the carb float valve sticks open, gas will flow into the carb, engine, out on the pavement, etc., unchecked.   From what you describe, it sounds like this was not your problem but, as have others, I put a check valve (electric solenoid) under the car at the tank outlet and wired it (through a concealed barrel switch) into the ignition switch. If the barrel switch is off and the car is stolen and hotwire started, it will not be driven far.  See Avanti Magazine, issue #170, pg. 48 for specifics.  Good luck!

[billsr2]

When I FIRST received my Stude, the first thing I did was toss all of the fuel lines & replaced with NEW hose that is rated for modern fuel.  Super critical.

You are a lucky man!

 

[Mark L]

Thanks for the suggestion about the check valve. I'll look into it.  I plan to work on it this coming weekend, including new rubber hoses.

[John Brissette]

21 hours ago, Mel said:

As you know, the gas tank on these cars sits on a ledge behind the back seat and, if the carb float valve sticks open, gas will flow into the carb, engine, out on the pavement, etc., unchecked.   From what you describe, it sounds like this was not your problem but, as have others, I put a check valve (electric solenoid) under the car at the tank outlet and wired it (through a concealed barrel switch) into the ignition switch. If the barrel switch is off and the car is stolen and hotwire started, it will not be driven far.  See Avanti Magazine, issue #170, pg. 48 for specifics.  Good luck!

I did much the same thing to my Avanti 35 years ago. I installed an explosion proof valve , mounted to the bar, that the top of the rear shocks mount to. it is wired from the ignition switch to a fuse, to a toggle switch to the valve. I might add that my Avanti is plumbed with AN fittings through out. Stainless Steel hard lines and braided stainless flex lines. No rubber hose.

JB

[Mark L]

I was able to quit work a little early today and found the problem. Since this is an early build car, the fuel return line to the tank comes off a T on the outlet side of the fuel pump. The port where the return hose should have been connected was capped off, and the hose to the return line was open.  The entire output of the pump is going to the carburetor, and the fuel return line is acting like a tank vent/overflow.

I spent the rest of the day's light siphoning as much gas as possible out of the tank and making sure the lines to the engine were drained. I'm going to replace as many of the rubber fuel hoses I can reach, and install a fuel barb on the T at the pump and get the fuel return line working again.

Edited February 24 by Mark L

[Mark L]

Tonight I ordered a motorized ball valve for the supply line from the tank to the fuel pump, a check valve for the return line to the tank, and some Sidewinder mandrel-formed hoses. I'm also going to get a fuse, an inertia switch in case of an accident, and a toggle switch for under the dash. My plan is to run a wire from the ignition circuit to the ball valve, with a fuse, the toggle switch and the inertia switch in series with the ball valve.

The particular ball valve I ordered is designed to remain open as long as its energized with a minimal power drain to keep it open. It's designed to automatically close if there is a loss of power. That way if any one item opens the circuit (ignition off, fuse open, inertia switch open, or toggle switch open), the valve will cut off fuel to the inlet of the pump.

[Mark L]

Earlier this week I replaced the plug in the T at the fuel pump outlet with a nipple, replaced all the rubber fuel hoses including the tank vent hose, and installed a check valve in the return line to the tank. I did not install the ball valve I purchased. I would have had to engineer a place to install it, which would have taken longer than the time I had available to work on it. The car had already been sitting on the driveway for the last month under a cover, so I needed to get it fixed and out of the weather.

I should probably write a technical article for the Avanti magazine describing how I replaced the vent hose. I looked in the article index that was printed in the 2024-2025 member directory, but didn't see anything that described how to do it. That was the most difficult and time-consuming hose to replace.

When I finished, I refilled the tank with 5 gallons of gas and leak-checked all the lower hoses. I then  drove to the gas station to top off the tank to verify all the upper hoses were not leaking. Everything was dry. Now I just need to install the bulkhead and rear seat.

Edited March 23 by Mark L

[Avanti1963!]

Mark, thanks for sharing your experiences.  I am getting ready to restore my gas tank and would appreciate any additional tips you have.  

[Mark L]

I didn't do any work on the gas tank itself, so I can't give any advice on that. Neil Loughlin posted a series of videos on You Tube where he works on an Avanti. In one video, he describes the steps he completed to remove and clean the gas tank. That may be useful for you.

The fuel hoses are pretty basic stuff. The vent hose is the most difficult due to its route. It goes through a rectangular channel and up into the right pillar between the rear window and the right vent window (directly opposite from the filler neck in the left pillar), makes a 180 degree turn, comes back down through the channel into the gas tank compartment, then goes down through a hole in the tank shelf in front of the right side of the tank. It apparently has (or should have) a clip that holds it up in the pillar. The hose passes through two holes going up through the channel and another two holes going back down.

In a nutshell:

I cut the ends of the old hose that were visible below the channel and pushed it and the clip up into the pillar. I will remove them in the future when I remove my interior for restoration. I'll put the clip on the new hose at that time.

I straightened out a wire coat hanger and fed it through the inside of the new replacement hose. I tied an additional piece of aircraft grade .032 stainless lock wire to one end of the coat hanger wire. The coat hanger wire was sticking out one end of the hose, and the .032 wire was sticking out of the other end. The junction where they tied together was crimped tight to fit through the interior of the hose.

I bent the end of the coat hanger into a hook and fed it through the holes in the channel so that it formed a guide for the hose.

I beveled the end of the hose to make it easier to pass through the holes in the channel.

I put some oil on the outside of the hose at the beveled tip to help it get through the holes.

I put some oil inside the hose to make it easier to remove the wire once the hose was installed.

I pushed the hose up through the forward holes in the channel while I was holding onto the coat hanger wire where the wire came out of the rear channel holes. The hose went up through the holes, was forced to make the 180 degree turn by the wire, and came down through the rear holes (after a lot of pushing and coaxing). When I saw the hose coming back out, I grabbed it with a pair of needle nose pliers and pulled it down the rest of the way as I fed more hose up into the pillar.

Once I was sure I had enough hose to connect to the vent tube, I pulled the wire all the way out of the hose, cut off the beveled tip of the hose, and clamped the hose to the vent tube. I then adjusted the amount of hose in the pillar to make sure I had a tall loop that was higher than the filler opening on the left pillar. I then fed the hose through the hole in the bottom of the tank shelf.

It took three tries to be sucessful. Adding the .032 wire and lubricating the hose were the two things I learned between the start and end.

Ok, I guess that was a pretty big nutshell.

Edited March 24 by Mark L