My 88, feed/supply = blue, return= gray.
If you're going after the busted shower-head...see my thread
http://www.oilburners.net/forums/showthread.php?63158-Rear-Tank-Is-Out!
Few weeks back I dropped the rear tank for shower-head repair...suggestion > siphon ALL the fuel out first, you'll be left with maybe a qt or so (no biggie).
The plastic supply and return lines are held to the frame via clamps...for needed slack remove them.
Remove the gas cap and filler hose > don't worry about the large rubber hose clamped to the tank side.
Lay under the rear tank and remove one skid plate at a time...support that side of the tank front to back with trucker type rubber bungee cords.
Simply remove the bungee cords and the tank will come down 'some'...with the needed slack in the fuel lines, reach-up and disconnect the electrical sender plug, the supply & feed fuel lines...AND...the the rubber vent line that is 'clipped' to the frame cross-member <> find that clip prior to the drop. I didn't and tore it from the frame(duh)
Once those are free, the tank will easily tilt down and to the passenger side, slide down and out onto your chest.
All in all not a bad job, I would rather do the above vs pulling the bed any day
BTW...wear eye protection from falling rust debris.
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