Fuel System help needed: M38

[Jake266]

M38 original and rebuilt but fuel is bad and tank requires draining and cleaning. Since I have never done something like this before, other than removing the old fuel safely and the proper disposal, how do I proceed with this task?
Any help would be appreciated.
Oh, and what is the easiest way to drain the tank?
thx

[Kendall]

There is a drain plug on the bottom side of the tank. That would be the easiest method of draining fuel from the tank unless the plug is stuck. Then you could siphon the fuel out or just pull the whole tank out. It sounds like the tank needs to be removed anyway.
Kendall

[ChuckW]

siphon the old gas into a container and dispose. Remove driver's seat assembly. Disconnect the lines, sender wires and hold down straps and clamps. Remove tank. Remove pickup assembly and sender unit from tank. Check with local radiator shops, many will clean and seal a gas tank.

[4x4M38]

Jake,
There are degrees of bad gas. Some gas is just dead and won't
hardly light but is still liquid. Next stage is dead, nasty stuff that
is starting to coalesce into a thicker mess. Last stage is the stuff
is just gunk that may be somewhat soft but no liquid, to just
a dry, thick putty like layer.

The first is pretty easy to clean. As advised, remove the tank and drain.
At that point you can probably put in some clean gas and agitate or shake
the tank to pick up the particles. Drain again and inspect visually
with a flashlight in the filler and sump holes. You can tell if it is clean.

The second and third versions are much more difficult. If you are
lucky enough to find a rad shop or tank shop that will clean go that
way if you can.

If not, this is what I did. I bought an old electric hot plate.
Also, filled the tank about 1/3 of the way and shook the tank
for a while to vapor free the tank. I plugged in the hot plate and
propped the tank on top, set the temp to about 2/3 and left it to
heat up with the cap off.

I monitored the temp, making sure that the water wasn't so hot as to begin boiling. After an hour you could see the water was milky and had paraffin floating in it . I unplugged the hot plate, shook the tank and poured out the liquid.

I did this three times and was able to remove nearly a of the dried
varnish and gas. The rest I got with a putty knife and wire brush.

[wesk]

Before obtaining a half dozen opinions here on this board which often do not always agree I would suggest you open your M38 service manual TM 9-8012 to pages 171 & 172. Give it a good once over review then ask questions here that you still have after the review of the manual.