Z Tech Tips '77 Gas Tank Removal and Renovation
Z Gas tanks and fuel lines are notorious for rusting and clogging due to rust and gas varnish.
My Z led me on a goose chase when I inserted a Fram filter and no gas came out of the line after the install. I am pretty sure it was just the collapsed old gas line hose not rebounding after I removed the clamp. I actually had to blow back into it to get the fuel to flow. This made me worry about debris in my tank so I dropped it.
Back car on ramps and place something to catch gas. I used a Walmart storage bin. A jerry-can with funnel on the mouth will work.
Remove 12mm gas tank drain plug
No I do not fill up at urinals or put beer in my tank. This is gas from winter storage. (and colour enhanced by digital editing on my pc... I loved those Star Trek colour enhancments from the 60's soooo much... now I can do them!)
In this pic you can see a lot:
- Metal sheet that protects the gas lines from road debris
- Fuel hose to motor via Fram filter
- Disolved hose particles in Fram G3 filter
- 10mm or 3/8" fuel hose
- Fuel return line
- Vent Hose to carbon canister and backflow valve
- passenger side fuel tank strap with 14mm nut
Open the hatch and then the fuel inspection lid to disconnect the wires to the fuel sender
Remove the bolts to the fuel filler tube.
Remove the passenger wheel well plate that protects the fuel lines from road debris (4 philips sheet metal screws)
Now you can look behind the passenger tire and see the hose clamp that holds the fuel filler tube to the tank.
Have fun loosening it! I did. Some penetrating oil may be needed. In my case the PO stripped the head so a small vise grip had to be used.
Drop the tank:
- Loosen the two straps using two 14 mm wrenches then unhook the passenger side.
- Put something under the tank to prevent it from falling too far.
- Unhook the driver side strap then lower
Move the tank to access the filler hose and vent tubes
As you can see, the two vent hoses are secured with hose clamps. I used channel locks to unseize the hose from the outlets.
If you had trouble with the filler tube clamp then maybe now is a better time to remove it.
PLOP (The comic)
Here you can see
- rubber bumpers
- 2 vent outlets
- fuel level sender wires and plug
- filler tube inlet
Here is a shot through the filler opening. As you can see it is pretty clean except for a layer of thing varnish. The PO had the car in a barn for a couple of years so I assume the "tidal line" is from that. I am pretty sure the tube in the middle is a device to baffle the fuel so that the fuel pick up does not suck air on turns.
The crud at the bottom appears to be rust. It does not scrap off with a stick.
Since gas floats on water. Rust will occur on the bottom of the tank first as well as in the air space above the gas where condensation occurs.
The larger upper tube is the send to the engine and the lower is the return.
Here is a shot of the drain plug. Again the rust is in the lower spots.
Here you can see the two vent lines. One goes off to the drivers side roof and the other goes into the baffle tube.
Maintenance & Troubleshooting
The left is after soaking for a day in solvents (Varsol then Naptha). The right is just 10min after a quick swish of muriatic acid.
Just use the acid!!!
Dispose of the acid by draining into a container then pour baking soda in to neutralize the acid. The acid is neutralized when the solution stops foaming upon adding more baking soda.
Victoria British Catalogue Order
Motor Sport Auto Kit