> With respect, the following method might work better for some. You have turned off the fuel lines to and from the primary filter you are changing. You change the filter. The fuel level will now be out of sight because of the fuel that came out with the old filter. You crack the tap on the tank side and simply watch for the fuel level to get to the top of the filter cylinder. Replace the top and you are done. No air, no bleed, no separate tank of top-up diesel, and little mess. Return all taps to normal operating position, final check for leaks, and you are off. < Richard's approach is certainly better if your tanks feed via gravity, i.e. the fuel level is always higher than the Racors. Not so in my case once the tanks are about half empty, so I sometimes find it necessary to top up manually. I would prefer that these filters be below the fuel tank level at all times, as indeed the OEM Frams were. However, when I replaced the Frams because they had no sight bowls, I found that I wouldn't be able to see the bowls unless I raised them by about 18 inches. Solved one problem but potentially created another - lesser of two evils in my view - and if it ever becomes problematic, I'll insert electric fuel pumps into the system. Cheers, Garrett