no oil pressure on D-4

First thing I would do is make sure the guage is working

Hi Team,
as Gary suggests above, first thing is to try another gauge--if you do not have another gauge disconnect the gauge line at the oil manifold and see if oil issues when cranking with the pony engine.
I know of a D4U series that sheared the drive pin at the oil pump drive gear driven by the camshaft (looking in parts books it seems both series engines use the same 0L1027 Pin in the oil pump drive)--this was down in Antarctica back in the day.
If you had water from condensation or such in the oil pan then ice in the pump could cause this or else it could be just the 30 weight oil in freezing weather not pumping also, or ice formed in the suction screen could block it off and stop the pump sucking oil.
Cheers,
Eddie B.

Thanks for the replies--today I plan to pump some oil into the line connection that goes to the head on the oil manifold and see if I can get the pump to prime. This should also register on the gauge. Would there be any way to draw the old oil out from the top? I can't get to the drain with the tractor where it is now. I have the means to vacuum out the oil if there is any way to do so. Keep the comments coming-I need to get the dozer going soon. Keith

This afternoon I was able to get oil pressure on D4 Cat motor--added some lighter oil to crankcase with old oil and primed the oil pump with old grease gun and 15-40 oil. Temperature here today is in the high 40's- much warmer than it has been of late. Still need to get fuel to injectors for engine to run. Good progress so far. Thanks to all Keith

Sounds like an oil change needs to be first on the list.

Hi Keith,
I purchased a down the dipstick tube oil change pump kit from a auto speed shop when I got quoted $40040 to change the oil and filters on my 2004 Nissan Patrol with 4.2 TDI diesel engine towing our 21 ft. caravan/trailer into a howling head wind when I was some 2100 miles from home and needed a scheduled oil change. Final cost was some $100--- $60 for the pump kit plus oil.
Cost $20 donation to service truck that did my mates Mitsubishi--$220 for the Pajero oil change--to take my 10 liters of old black oil.
Be well aware that the oil needs to be warm for these little pumps to work. Maybe put a heater under the belly plate, if fitted, to warm the oil-- BE AWARE of sticks, leaves and oil soaked dirt etc. in the belly plate that could ignite and destroy your machine and shed etc.

Cheers,
Eddie B.

Keep working at it. My 5T has a rod thru the block on the pony, the rest of the tractor is in pretty good shape, may even get around to replacing the pony in 2021.

Hi Keith,
I purchased a down the dipstick tube oil change pump kit from a auto speed shop when I got quoted $40040 to change the oil and filters on my 2004 Nissan Patrol with 4.2 TDI diesel engine towing our 21 ft. caravan/trailer into a howling head wind when I was some 2100 miles from home and needed a scheduled oil change. Final cost was some $100--- $60 for the pump kit plus oil.
Cost $20 donation to service truck that did my mates Mitsubishi--$220 for the Pajero oil change--to take my 10 liters of old black oil.
Be well aware that the oil needs to be warm for these little pumps to work. Maybe put a heater under the belly plate, if fitted, to warm the oil-- BE AWARE of sticks, leaves and oil soaked dirt etc. in the belly plate that could ignite and destroy your machine and shed etc.

Cheers,
Eddie B.