Fuel Tank Maintenance

[Jabs1542]

I recently purchased a Type 65 Coupe (Bob Littlefield’s 2014 SEMA show car), there is much to be done on this car - it had 600 miles on it, so the car was never really driven.

I get gas fumes while sitting in the garage. No drips, no leaky hoses, no fumes when first parked, they accumulate over the evening. My suspicion is that the gas tank vent, or other tank plumbing, needs some work. Since I didn’t build this car I’m not sure what all is up in there so I’m asking a few questions in order to come up with a plan.
1) Looking at other’s build threads it appears there is hard structure below the tank, so the concept of ‘dropping the tank’ will not work - correct?
2) Looking at the rear cargo area I have panels on each side, it looks like my best access is on the passenger’s side. If I remove the panel on the passenger side will I have access behind/inside the fiberglass shell? Or does the shell dip down into that area covering access?
3) Has anyone had to get to their tank after their car was completed and running? Any tips?

TIA

[GoDadGo]

Is the car equipped with a Fuel Safe fuel cell or a Mustang OEM fuel tank?

My pal Gerry has a Gen-1 Coupe that had a Fuel Safe fuel cell and we had to pull the sucker because the bladder had failed. The bladder sat in an aluminum tub and the assembly was a pain in the neck to remove. Our solution, since the car is not raced, was to have a custom tank built to the same dimensions of the fuel cell's tub since the mounts for the Mustang Tank had been removed.

> If the car is fitted with a fuel cell, the bladder may be leaking which would need to be replaced since they don't last forever.

> If the car has a Mustang OEM fuel tank, you may have a leaky filler grommet, a pinched sending unit O-Ring or a poorly configured venting system.

NOTE:..I remember your car and it was really something special and must be insane to drive.

https://youtu.be/1wymc0EopgY

Good Luck & Watch Your Pinkies!

[Bob Cowan]

Some braided steel flexible hoses are famous for emitting a fuel smell while parked. Lots of talk about that over the years. Since you don't see signs of leakage anywhere, I would look at that first.

[J R Jones]

Your car has fuel vapor/smell potential from engine to fuel tank. Before you take anything apart troubleshoot and try to identify the source(s). A carburetor is a potential source, as is fuel pressure. Does the fuel tank vent go to a carbon canister?
A thread in the last week discussed fuel line liner permeability and compatibility with ethanol in fuel. Look it up and note the fuel vapor sensor one poster uses.
Back in the old days we would pressurize various systems with A/C Freon and use a Freon leak detector to find leaks.
jim

[edwardb]

GoDadGo's point about whether it's a fuel cell (somewhat unusual...) or the more standard Mustang tank is a very important one. If it's the Mustang tank, you should see two straps across the bottom of the tank. There are bolts holding the straps right behind the rear suspension. Then pivot bolts on the back just inside the body. This type of tank can be dropped relatively easily by supporting it (I use a floor jack with a piece of plywood and some padding) and loosening the front bolts. That's assuming it has little or no gas in it. Gets heavy and unwieldy with a lot of gas. Note there's usually a plastic cover on the bottom, between the straps and the steel tank. That might be what you're seeing. But dropping the tank should be the last resort. Check everything else first. If you don't see any obvious leaks, vapor from the vent hose is possible. It should have some type of charcoal cannister.

If you're tank doesn't look like what I've described, and is more square or boxy, probably a fuel cell. No experience so can't help you with that.

[GoDadGo]

GoDadGo's point about whether it's a fuel cell (somewhat unusual...) .

The seams on the top of the cell delaminated and it started leaking.
Kerry Smith "The Gator Pot Guy" built the replacement tank for us.
Mr. Smith is also known as the "Cajun Wheel Doctor" so he stays busy.
Kerry normally doesn't do fuel tanks for Hot Rods, but he made an exception.
He Tig-Welded my headers after I tack welded them using Volcanic Bird Poop Method.

Seafood Boiling Pot:
https://www.facebook.com/gatorpots/videos/301016965305955/

Wheel Repair:
https://www.facebook.com/CajunWheelDoctor/

[Ltngdrvr]

As I recall during my web browsing, the SEMA car in question was built like a fairly standard FFR type 65, so it has a fox Mustang tank.
I would suspect that either the vent isn't properly set up, or maybe the gasket for the pump/sender is leaking.