With just a few operating hours on the tractor I noticed the same thing happening again. I pulled the pump myself finding a seal compromised, (fuel pump side) once again. Examination of the brass sleeve showed nothing really to be concerned with so with new seals, and engine assembly lube liberally coating the seals and mating bore, I slid the pump back onto the splines. A few operating hours later, I notice the oil level growing again; rather profusely I might add too.

Once again I pulled the pump and this time sent it back into the fuel shop for evaluation. A couple of days later the fuel shop calls and not with the news I'd expected. The prior technician who rebuilt the pump originally was no longer employed there and the guy working with it this time tells me the brass sleeve is not any good, (via measurement) so it is now replaced. There is no charge for this as they've been in the loop since it was originally rebuilt but sure a pain in the backside. I'm going to reinstall the pump again either this afternoon, or tomorrow and hopefully this will be behind me.

The engine in this tractor sure runs and performs well but as many times as it's been drowned in diesel fuel, I'm certain there is no sludge buildup internally. I noticed this as the cold oil pressure was good, but rapidly decayed as the engine warmed. I check oil prior to starting work too and it gained a couple of gallons in the crankcase within an hour. The compromised seal was almost torn in half so a profuse leak internally right into the crankcase.   

Only diesel fuel was used for assembly lubricant with these seals.

I also keep extra umbrella seals on hand. Think I have eight left as purchased two packs of 10 a couple of years ago. I used the seal collapsing tool to install the pump but did not use the expander to install the seals onto the driveshaft. The seals are plenty supple so used my fingers and engine oil. Plenty of lube and the pump went onto the engine almost effortlessly. Having changed all the engine oil filters and with none of the cartridges pre filled, I cranked the engine with the fuel shut off for 15 seconds. When the fuel was allowed the engine almost immediately came to life and oil pressure came right up to almost 80psi on the gauge. Once hot it is still carrying over 50psi at low idle speed and races to 75+ psi with an increase in engine rpm.

Going to allow a full cooldown and then retest tomorrow.

I have discovered one thing with working on this tractor and the contorted positions one much get into for access, and I sure ain't no teenager any more. Although I still fit between the track shoes and tractor body, it is rather difficult to get into, and out of the positions needed citing lack of room. Of course now I care a lot more about getting hurt than used to so more fully evaluate my surroundings rather than "Hold My Beer"!!! attitude.     

I agree. Although it's been over 45 years I still fondly remember crawling all over these tractors when new to see what made them "tick". It was a lot easier then and bruises along with scrapes all healed. 

Now, I'd just as soon not get them in the first place..... 

Ran engine another three hours today and no elevating level to the crankcase oil. No smell of diesel fuel that I could notice. 

Think this one can be put to bed finally. Informed the prior owner and he shares my enthusiasm with the apparent success.

Gesture sure is appreciated, but not necessary I told him.