I have a 97 Case 580 SL backhoe with a diesel engine. The machine typically starts on the first click, everytime. Since it is stored inside, the only exception to this is when we leave it outside in the cold, which is to be expected. Friday morning, I needed the machine to start loading some sand, so I hopped in (it had been parked inside) and turned the key. The engine turned over fine, but I surmised that there was no fuel getting to the injectors. I opened the primer screw on the fuel line after the fuel pump, and air came out. Next, I pulled off the fuel/water separator. It was almost empty. I made sure the fuel line from the tank was clear, put a new in-line filter on, a new separator, then primed it. Still nothing. Then, I opened up the injectors until diesel flowed, bingo, the machine started right up and worked fine for the rest of the day. Any ideas what might have caused this. I am afraid that because we won't be open for a few days it will become airbound again. Is this the sign of a bad fuel pump?? Any advice would be helpful. Nothing is worse than counting on a machine to start and finding out it won't when you need it.