1979 JD 850 Soot in coolant

[goodowl]

Howdy,
First noticed this last fall getting ready for winter.
I cracked the injector lines one at time, she ran same on any two.
Soaked injectors with ATF/acetone for week, pulled them using the
banjo bolt with a couple of washers.
Compression all 3 bit over 300 psi.
Leak down 100 psi:
#3 (on the left) bubbled into radiator and into crankcase.
#2 & #1 bubbled up right side head bolts around the nuts / crankcase.

Pulled the head, it came off clean of gasket.
Straight edge with .004 feeler no go

First time ever pulled a diesel apart.
Here's a pic of the top of the head gasket.
Not sure what to make of it.
Comments suggestions welcome...

 

[TimberHole]

You have already violated my first rule of maintenance......wash down engine before tear down! I did the exact same thing on my last 2 tractor projects so I made that rule

Looks like you were overdue for a head gasket. Are you going to do the head? These little Yanmar's have a reputation for cracking heads. I would buy your head gasket from Deere. It's better quality. When I did this I also went thru the cooling system and replaced the temp/pressure sending units. I wanted to be certain my warning lights worked.

 

[goodowl]

Hey! Thanks fer the comments
actually I did pressure spray the rocker cover/head/intake
before I started just didn't get overly aggressive any lower.

I don't know whether that's typical gasket failure or not?

Seeing how totally ugly the gasket is my thought was that the head loosened over time.

Under x20 magnifier don't see any cracks.
I'm tempted to buy the JD gasket & put it back together.

 

[TimberHole]

This was the head gasket I pulled off my first JD950. It hadn't been on long and turned out to be a failed attempt by the previous owner. I don't have s good pic of the second tractor but included the only shot I had. Neither tractor gasket looked as bad as yours. One of my heads was cracked and the other wasn't. The head without cracks was a 1200 hour head.

 

[mddorange]

:welcome:
To the TBN forum Goodowl. We are glad that you joined.

So, where is Eagle? How many hours on that engine?

 

[goodowl]

Thanks for the pics Timber, so maybe these can be put on upside down then?

Hi MddoRange, Big wave from East of Lincoln Ne out between the corn & bean

 

[TimberHole]

Thanks for the pics Timber, so maybe these can be put on upside down then?

Hi MddoRange, Big wave from East of Lincoln Ne out between the corn & bean

I think the gasket is symmetrical but I think it's marked.....kinda forget to tell the truth. Its just my own personal theory but I think the studs work loose at the block over a long period of time. My advise is to make certain your studs are fully seated in the block and that the threads at the top and the nuts are clean and free. Should be able to run those nuts by hand. Get the head and block completely clean. Oil the threads as specified in the overhaul manual and torque in sequence to the proper value. Both of mine are running well but I didn't take any shortcuts like the previous installer did on my first tractor.

 

[goodowl]

Sounds like sound advise TimberHole, thanks a ton for your time!

Don't know what we'd do without this old girl, up here in the frozen tundra.

Watch out fer them hossflies!

 

[TimberHole]

Please post your results when complete as it will be helpful to others. I have a service manual if you need any info out of it. I assume you've figured out the Deere parts diagrams are available online.

Good luck!

 

[goodowl]

Sorry MddoRange I didn't see your other question.

When I bought it had 1375, it's close to 2000 hrs now.

Do most subscribe to the theory that for an engine like this one,
beefing up top compression would likely cause metal to majically
appear in the oil pan?