Priming a diesel

I just picked up my first diesel, a Cockshutt 570, and I recall on this site a few times being mentioned about priming a diesel. So when do I need to do this?
I've noticed a small fuel leak when it is running, but if I turn off the fuel overnight will I need to prime it in the morning? If I run the tank empty, do a refill, then is this when priming is to be done?
Oh, BTW, how do I go about doing a prime job???
Thanks

You need to prime it when you run out of fuel and when you change the fuel filters, or do any work that involves air getting into the fuel lines. A small fuel leak is no big deal and you do not need to prime that. Say you do something in which you need to prime it. First thing is start pumping on the lever that is on the fuel pump. Pump it until it feels like its not doing anything (about 20 times) then crack open the bleeder screw that is on top of the first fuel filter, bleeder screw is actually ontop of the fuel filter housing (if it has 2, it will be the first filter after the fuel pump) when you open it you will hear air escaping. Depending on how much fuel line there is, you may hear air escape and see no fuel. Close the bleeder screw and pump some more like before (you cannot overpump it so dont worry about that). Open the first bleeder screw again and if you have diesel come out close it up. Go back to pumping (finger exercises), do the same with the second fuel filter (not all second fuel filters have a bleeder screw) if it doesnt then loosen the fuel line that goes to the injector pump. Once you get fuel there tighten it back up and pump some more. Then open up the bleeder screw(s) on the injector pump. They are normally about 1/4" bolts that are on the side of the injector pump. They are not the ones that are connected to the throttle rod, or tied with wire so you cannot mess with them. If you cannot find the bleeder screws on the injector pump its not the end of the world, dont worry about it. I dont mess with priming each line going to the injectors because they wont have air in them unless you remove the injector pump. Once your done with that fire her up, and set the throttle mid way up, to help clear out any little bubbles that may still be in the lines. If it dies, just give it a crank. I have dealt with some engines that dont have primers so you just have to keep cranking. Crank for about 10 seconds then let the starter cool down. There is nothing worse than smoking a starter trying to get an engine to crank over.

I don't want to sound like a smart a$$ but you really need to spend a few hours with the operators manual. Time spent reading will more than offset the costs if you don't.

A diesel will run on WD40. Instead of smoking a starter, keep shooting intermittent squirts of WD40 into the intake to keep the engine running until air is worked out of the lines and the engine will run on its own.

Like someone else said, spend some time with the owner's manual. When I was a salesman with GM, we were told that of all the questions vehicle owners phoned in to GM's consumer hotline, 62% could have been answered by reading the owner's manual.

Fix the fuel leak. fuel out, air in.