I have a 1085 MF, and the other day I went to change the fuel filters. After installing the new filters and following the directions in the owners manual, I can not get the fuel system to prime. I think I'm getting an air lock some where. Because I open the vent plug and start working the primer pump and no fuel comes out. But if I loosen one of the filters, fuel will run down the outside of the filter. I have even removed the out-go fuel line in hopes maybe it would help vent air, but no luck. I really need to get this problem solved, before I go insane. Thanks.
I don't know the specifics of your particular machine but here's some general bleeding intructions for you to follow. You have to make sure that you have fuel flow without blockages in the fuel delivery system. If you have fuel to the inlet side of the fuel filter and not to the outlet side, make sure that your filter is installed properly (sometimes an oring or seal sticks on the filter head and prevents proper installation) and make sure there is no blockage in the filter head itself ahead of the filter.
Bleeding a Diesel Fuel System
Start at the fuel outlet of the tank (inlet to the filter). Shut the tank valve, remove the line at the filter inlet and holding a suitable container to catch the diesel fuel, open the valve. You should have a CONTINUOUS rush/flow of fuel out of the line. If it dribbles or is intermittent, check the fuel cap for a blockage of the fuel vent or the strainer upstream of the valve for clogging. The strainer/screen is attached to the shut-off valve, and is positioned up inside the tank. You will have to drain the tank and pull the valve to clean the screen.
If you have good fuel flow at that point, reconnect the line and open the bleeder screw at the top of the filter. Turn on the tank valve and wait till you have a steady flow of fuel with no bubbles at the top of the filter, then close the bleeder screw.
Your pump may have a bleeder screw. If so, open that until fuel streams out with no bubbles, then close it. If you cannot identify the bleeder screw, loosen the inlet connection at the pump and purge air at that point.
Go back and make sure ALL the fittings in the fuel delivery system are tight so they cannot suck air.
Make sure the battery is fully charged. Loosen the fuel fittings at the injectors, either one at a time or all at once. Crank the engine till you see all fuel at the injector fittings and then tighten the fittings. If you do indvidual fittings, the engine will usually start before you get to the last fitting.
Alternatively, you can "tow-start" it to save wear and tear on your starter. Leave the injector lines cracked open at the injectors at first to purge the lines. Then tighten them up and she should start.
Your injection pump puts out a very small amount of fuel (high pressure/low volume). BE PATIENT. If the lines are totally empty, it takes a lot of cranking to fill them up.
sixbales & Jerry/MT