D5k2 will not self prime

[CrackerTracker]

KYY1751, 3999 hrs - A few days ago I decided to crack open the drain on the fuel water separator located near the rear of the engine (cat part 479-4137) to check for any water. There was none. Once done, I could not get the drain valve to stop leaking. I decided to drive the dozer up to the main shop to work on it but after moving about 150 feet it sounded like it ran out of fuel and died. My guess was that it sucked in air through the leaking separator drain valve.
The new separator came in today. (I know, I could have repaired the valve, but what the heck.) After installing the new separator I can't get the machine to self prime. I tried putting fuel into the separator but still no luck. My understanding is that to get it to self prime, turn on the key and leave it on for two minutes, then try to start the engine. I've done this probably 20 times with no luck.
Any thoughts on what I should try next?

 

[Nige]

My understanding is that to get it to self prime, turn on the key and leave it on for two minutes, then try to start the engine.
....Any thoughts on what I should try next?

Doesn't the electric priming pump work.?
The attachment is taken straight from the Operation & Maintenance Manual. I assume you don't have one.
Search https://catpublications.com/ for SEBU8498. You can download a pdf copy for $52.........

 

[CrackerTracker]

Nige, Thanks for the reply. Yes, I have a Operation & Maintenance Manual and tried what it said to do probably 20 times or more. I could hear the electric pump run for the two minutes as stated in the procedure but the engine would never start. I was finally able to get in touch with my local CAT dealer the next day and the technical expert there was able to help me. Although he couldn't tell me exactly what the problem was, his input put me on the right track. It seems that if the electric primer pump gets full of air it may not work properly. To get things working I disconnected the inlet to the separator and pushed fuel through it and into the primer pump. While I was pushing the fuel, I cracked open the drain on the fuel filter (toward the front of the engine) until I had a small flow with no air. I put everything back together and the engine then started as it should. I've been running the machine on and off for the last couple of days with no issues.