Can't seem to get all the air bled out of fuel lines
 

TRUCK INFO: 1998 Sierra 2WD 2500 Overdrive automatic. 6.5 Turbo Diesel, with 150,000 miles on it. Was diagnosed by local GMC dealer with bad lift pump that I had JUST replaced three weeks earlier, when it failed. At that time, I paid dealer 113 dollars to bleed system, and they ran a systems check, and he said that it threw NO codes.
Late last week, the truck fired right up, and after idling for a little over a minute, it completely died, the same thing it did when I replaced the first LP.
A mechanic at the dealer snapped the plastic bleed screw on the fuel filter, and REALLY buggered up a half-assed fix for it. The Dealer let me tow it home with no charges due, where I replaced the lift pump again, plus replaced the fuel filter element.
I then bled the filter using a 3 foot long clear hose into a jar, with the other end on the nipple of the bleed screw. I cycled it three times until NOTHING but fuel, (all spotless), came out.
After four tries at starting, I rechecked to see if any more air was in the filter, and it was pure fuel.
Five minutes later, I tried starting it again, and it tried to start, but no luck. Five minutes later, I tried again, no luck. A list time before coming in here, I tried, and after fifteen seconds of cranking, it spent five seconds trying to start, but no joy.
I was told by the Service Manager to NEVER use the "T" handle on the front of the engine to bleed out the rest of the system, so I haven't touched it though I have been tempted.
We REALLY need this truck to be back on it's feet, as it is the ONLY truck that we have, so please give me ideas. I have twisted wrenches for twenty years on Fords, V.W's, and am a unit shop mechanic in BMW, Porsche, and Jaguar, but ALL Gasoline engines only.
Brie