I could use some help. I'm a caterpillar guy 35 years. This Doosan D24 got water in fuel. The pickup tube was changed and water/fuel filter changed. When the bulb is squeezed it will harden up but loose prime and go flat after cranking. While squeezing the bulb then letting off I can hear a bubbling sound. Bit sounds like it's coming from a hose that's the return from the fuel cooler. That line seems to be stuck or attached to something like perhaps a valve or fitting going to the tank. It's not the fuel feed lin line at the fuel pump e. I checked the metering valve by removing it and supplied a brief 12v and it clicks so appears to work. Also when pulling it water dud come out of the fuel pump in the hole I removed the metering valve from. I must mention when it was dragged back to the farm it got down to -11° also when squeezing bulb there is indication of air at the clear plastic T that supplies the bulb the other 2 lines hook from cooler and other is from left side of fuel pump. I cracked the line at pump and it getting fuel. While cranking there's no vapor or smoke from exhaust. I hooked fuel pusher can to purge air and bleed from top of filter. No codes except AC. I did not hook clear lines to back of injectors to check excess leaking.