I have a question, how hard is it to rebuild the diesel cummins engine in an 1840 case{4-390}. I have a 95 that has around 7600hrs, it still runs good but I figure maybe I should rebuild before it's to late? I am mechanically inclined but have never rebuilt a diesel, is this a possible DIY job? Thanks for any info
Maddog, "If it ain't broke - don't fix it" Is it using oil? If not, leave it alone. I've seen huge hours on those 4-390's - if properly serviced (every 200-250hrs) & tappets regularly adjusted - 20,000 HRS plus! - injector pumps & injectors had been done on them - But they never even had head off. 4-390 - Almighty!
It runs strong and doesn't seem to use any oil. I do have some small hydraulic leaks, so I figured while I have it apart to fix them maybe I should go through it? I just purchased it this summer, and changed all the fluids. Not sure how well it was takin care of before, no records. Thanks for the reply
As stated above the 4-390 is a very reliable engine that can easily go over 10,000 hrs before any major work. If it doesn't use oil I wouldn't open it. It is likely to need injection system work if it hasn't already been done. Seen a lot of those engines become hard to start around the 8000hr mark because of weak injection.
thanks, It hasn't had any issues with starting unless its been cold{below 35F} If I remember to plug in the heater it starts fine.