I removed my pick up early on to remove the screen. To make the job easier and to confirm that you have no air leaks after the job is completed I recommend removing all fittings in the order,
(1) remove fuel hose and plug it with a 3/8 barb fittings and a pipe cap threaded on the male barb fitting threads.
( 2) Remove the fuel valve. Unthread it from the pipe nipple and reducer
(3) Very important!!!! The large nut that sits flush to the tank top surface must not move when you are unscrewing the tank fuel pickup tube. Back the nut up with a properly sized wrench. Hold that wrench when loosening the pick up tube fitting. The Pick up tube fitting is going to be tight and will require a good amount of force to loosen. HOLD THE BACK UP WRENCH ANY TIME YOU ARE TRYING TO LOOSEN THE PICKUP TUBE FITTING. Once the fitting breaks loose apply a small amount lubrication to the threads and work the treads until it loosens then unscrew it the tube will pull out of the tank. There is a screen on the bottom of the tube remove it.
The large nut that sits on the surface of the tank holds and seals the threaded insertion installed in the tank in place. It is very important to not disturb this fitting by loosening it. It may leak if it is disturbed.
Do not let this happen
http://i363.photobucket.com/albums/oo76 ... ure010.jpg
Pick up tube
gallery2.php?g2_itemId=52942
gallery2.php?g2_itemId=52966 This was my arrangement after installing polishing system. Notice the one port used to access the tank for inspection of water. The pipe plug is removes and an 1/8 inch tube is inserted to the bottom of the tank. Using a small drill driven oil pump and a container the sample is taken from the bottom of the tank.