I'd say getting the water, rust and dirt out is your second priority
with the first being ..... taking care of the cause that allowed it to
get in there in the first place.

It's likely that the seals at the top of the tank are bad .... or ....
the top of your tank is rusted out or both.  Either way you'll want to
drop your tank and make sure the tank will seal against incoming
moisture.

While it is out, draining and cleaning will be MUCH easier anyway.

Here is something that might help (supplied by Ken Wilfred).

http://www.vanagain.com/gastank1.htm

Mike

'84 GL 7 pass
'85 GL Westy

Hi all

Some weeks ago I posted a message about the engine was suffocating. I
did receive several tips, one of hose where to check for water in gas.
So done, and yes, plenty of water. Water was not the only thing I found.
Lots of brown dirt or rust particles were also in the gas. Changed my
gas filter (gas inside the filer was all brown). Hope none of the
particles has reached the injectors. Emptied out as much gas as I could
by lifting the car on front driver side. Filled 10 litres of gas and
added water remover (not sure what it is called in English).

The car is still not handling well. Rechecked for water, and yes it is
still there.

Two questions:

Anyone know how to completely empty the gas tank ?

I would probably need to get rid of the dirt particles that are in my
gas tank. Can it be cleaned while mounted on the car and if not, is
there any problems with removing the tank that I should be aware of ?

It is a -86 Caravelle with a -85 1.9L injection engine (no converter or
oxygen sensor).

Thanks