d2 5u diesel in oil

Usual source is dried up o-ring seal between the filter tower and fuel injection pump. Allows fuel to find its way to main sump. Same o-ring used at governor end of the fuel gallery. Replace them both while your in there.

There is a couple of really good threads with photo's on this subject in here! One of them describes what tools are necessary to get the rear nuts off, minus fat fingers of course! I am fairly certain one thread even has the current part numbers.

Been there and done that. Had an old Cat mechanic say he never saw one do that before, but that was like 20 to 25 years ago. As these machines age, it is becoming more common a problem. Who would have thunk that after 60 to 70 years these machines would still be running.

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These are the gaskets and seals needed to do the job. Best to use a hoist for fuel injection pump/gov removal because it weighs about 80 pounds, which can be difficult when leaning over the tracks.

I just went through this with a D6 this spring.I was some what intimidated by what could be involved. It was not that big of a job.I had 2 people to help both have a general understanding of mechanical things but none of us had ever been in a Cat fuel system.The explanation and pictures from members here made it ease.Less than 6 hours with BS thrown in,and the young guy muscling it in and out,even though I had engine hoist there.


I am sorry I never came back with a report,but have had other little things to work on like a different hydraulic set up. Have started the engine twice but never move so I had been waiting to really us it before saying I had been successful with the repair.


As a word of warning have seen a little fuel in the engine oil on different machines,but this was different. This would of been costly to not fix and try to get just a few more hours out of it.This tractor had been used less than 2 days a year since 1985 until a steering clutch rusted up,guessing 199?. It was used for fire breaks on CRP land retirement program on the farm it worked on before land retirement. From then until 2013 it had not been started,fixed steering used it 50 to 100 hours.This spring after using oil looked thin as I check at cool down before stopping . It uses a little oil but looked fuller,heat expansion,how level it sits and other variables all come into play.In the morning the thinness was more alarming with cold oil,so I changed it and ran a short day.It was thin again,and had not gone down from burning oil,drove it back to the yard.It sat for 2 or 3 weeks until all things lined up to fix it at which time it was way over full,drained close to 15 gallons out of it. In this case when the seal failed it went fast.Don't know if it leaked with the engine stopped or if that happened in the hour it took to get home. Just something that seems to come with the age of all these Cats.

hi
got started on it finely ,got the pump off and found the o-ring between the filter and the pump was hard, where is the o-ring on the governor end of the pump.
thanks