Easy way to drain gas tank? (Page 2/2)
Mickey_Moose MAY 06, 05:01 PM
I recently did this.

Used the fuel pump (jumped 12v from fuse box to ALDL plug fuel pump pin), disconnect line at filter imput and flowed into a gas can. Pump was noisy and figured it was on it's way out so wanted to replace it before it left us stranded.

Was surprised that the tank was spotless inside.
theogre MAY 06, 05:06 PM
Most times you often just dilute stale gas and maybe add "dry gas."

Many problems come from water or ethanol... If you remove the fill hose as my post above... You can often find the problem by using a small weighted tube to siphon the bottom of the tank into a clear tank/container because Gas will float on water or water and ethanol mix. (Gasohol's ethanol will come out a solution if the tank has water inside, EVAP issues or Cap is Vented. Is a very big problem in Marine engines.) You can use small USB camera etc to look w/o pulling whole tank too.

[This message has been edited by theogre (edited 05-06-2015).]

Patrick MAY 06, 05:17 PM

quote
Originally posted by Mickey_Moose:

Was surprised that the tank was spotless inside.



That's been my experience as well with five or so Fiero gas tanks that I've dropped.
inheritancefiero MAR 21, 02:22 PM
After reading a lot of suggestions I did the following as I could not access the tank from below. I attached a hose to the fuel filter inlet line and ran the hose to a gas can. Then I inserted an air hose into the fuel filler neck and jammed it with rags to form an acceptable seal. I pressurised the tank and drained a half tank in ten minutes. I did have to hold the rags tight to form a seal on the filler neck. Beats dropping the tank and hotwiring systems.

[This message has been edited by inheritancefiero (edited 03-21-2021).]

Patrick MAR 21, 03:11 PM

quote
Originally posted by inheritancefiero:

Beats dropping the tank and hotwiring systems.



Just a note... If the fuel pump is still working, "hotwiring" 12v to the fuel pump terminal of the ALDL port is about as simple as it gets. And if the fuel pump isn't functional (or if the short length of submersible hose has rotted), then the tank's gotta be dropped anyway.

I don't have an air compressor... but if pressurizing the fuel tank to empty it before dropping the tank to replace a dead fuel pump works, great idea!
Dennis LaGrua MAR 24, 03:01 PM
You can try running the fuel line with a hose to a 5 gal bucket and then wire across the ALDL connector from the fuel pump pin to the ground pin. The fuel pump will turn on and the tank will empty but be careful to not run the pump dry or you can damage it or burn it out.
That should work but if you have too much dried varnish at the tank bottom it might not give satisfactory results.

------------------
" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

Will MAR 25, 08:41 AM
You can disconnect the fuel pressure line at the engine or fuel filter, run that to a bucket and hot wire the fuel pump to pump fuel out of the tank.

You should drop the tank to see what shape both inside and outside are, as well as what condition the center tunnel in the body is in.