John Deere 950 Yanmar 3T90J Oil in Radiator

[chriswheeler]

Yes, I'd re-ring it, you are already there. 1000 hours isn't much for these, I bet the rings are fine most likely, but rings are cheap and with freshly honed sleeves, it freshens up the whole assembly. I just used all thread and scraps of steel I had laying around, it didn't take much of a pull to break them loose, and you don't have to move the liner much until you can remove them by hand. Think I remember using 3/4" course thread all thread and they came right out. Spent some time cleaning up the sealing surfaces in the block where the new O rings will seat, got them spotless. In your case, I'd be looking closely at the seating surface in the top of the block for signs of a leak. If there is one, you will see it. But most often it's the O ring that fails and after removing the sleeve, most likely won't be able to tell looking at the ring. Sounds like you are almost halfway done at this point, the rest is down hill. If you have a machinist friend with micrometers, ( inside and outside ) it would be good to measure the bores of the sleeves for any taper and the pistons to see if they are still in spec. If you don't have a friend with the tools to measure, I wouldn't worry to much about it with only 1000 hours on that engine, most likely just fine. A word on the hour meter on that one, you probably know that engine hours are measured @PTO rated speed, so depending on what it was used for, it has more, just no way of knowing what the actual hours are.
Chris

 

[chriswheeler]

Yes, I'd replace the rings, a golden opportunity to do so, even with only 1000 hours on it, it will never be this easy to get to the rings again, Hoye tractor has them. In fact, they should have the rest of your parts as well, might be aftermarket, but more than good enough. I have a local John Deere dealer and priced the parts from them, they were always more than double the cost. Didn't take much force to break loose the sleeves, I used some scrap steel I had around with a 3/4" NC all thread for the puller. After moving the sleeves a half inch or so, they pulled out by hand. Not much force at all. If you can't get your hands on a ball hone of the proper size, the machine shop that does your head should be able to do this for you, not much cost.
Chris

 

[TimberHole]

Looks like there has been a couple of posts in this thread since my let post but I'm not seeing them. Does anyone else see a post from yesterday or today?

 

[chriswheeler]

I've been having some problems with this forum lately, my posts just disappear, some show up later, some don't ?? Think something is going on either with this forum or it's server ?? You see the 2 posts above are almost identical, one just disappeared for awhile ?? One is still missing ??
Chris

 

[Spanner]

Yes, I'm following this thread and get notified of new posts but find none when I visit to look. :smiley_aafz:

Agree to new rings.

Just wondered if PO moved the engine, (rotated) when the head was off the last time, and failed to clamp down the liners? One could have moved slightly and not been fully seated upon reassembly?

On the pic of the head and gasket there is an unusual black mark at 7 o'clock on the Left cylinder hole, in the gasket. Was that a sign of leakage?

You refer to "mushy" gasket material - Do you mean this laminated composite stuff? It's pretty common lately. Were you expecting the traditional copper & asbestos type of gasket perhaps?

I'm wondering if the liners can be crack-tested also?

You are doing great so far. New rings, liner seals, gasket...
You have to do the whole head fully from here. Crack test. Planed. Valves all out, ground, stem seals etc.

Keep at it.

Re: Head Gasket. Check the Part No. I get #M808712.

Also, I see the notes -
"(NO SERIAL NO. BREAK FOR 950) (SUB FOR CH12897 OR M810713)"
and
"(GASKET HAS 10 HOLES BUT WILL WORK IN PLACE OF 8 BOLT GASKET) (SEE DTAC SOLUTION 13860)"

on the two versions of 950 listed.

Now get your dealer to print-out the Technical note called "DTAC Solution #13860".

I suspect it will just say the 10-hole gasket replaces the earlier 10 & 8 hole gaskets. But it may have more info as well.

What is the VIN number of your tractor? Can you post a photo of the VIN plate please?

Regards,
:wrench:

 

[TimberHole]

Thank you for the replies. Very, very helpful! I dropped the head off at the machine shop this afternoon. These guys only do heads and are the real deal. They also fix a lot of cracked heads. Said he fixed a cracked Yanmar head yesterday. My head looked good with no apparent cracks. Probably take a week or more to get it back but will be worth the wait, assuming it is serviceable. I told him to, at a minimum check for cracks and re-deck. I told him to do whatever he thought the valves needed, including a grind if needed.

I'll get a puller made in the next couple days and get the sleeves out. I also need to sort out a parts list and get them headed this way.

Here is a pic of the data plate.

Not sure if I mentioned it before but I bought this tractor from the original family that purchased it new. Very cool unit and I love knowing the history. They used it for cutting hay and a little auger work.

 

[TimberHole]

Spanner I'll look at that pic of the head when I get home and make a better post. Thanks for your help!

 

[TimberHole]

Yes, I'm following this thread and get notified of new posts but find none when I visit to look. :smiley_aafz:

Agree to new rings.

Just wondered if PO moved the engine, (rotated) when the head was off the last time, and failed to clamp down the liners? One could have moved slightly and not been fully seated upon reassembly?

On the pic of the head and gasket there is an unusual black mark at 7 o'clock on the Left cylinder hole, in the gasket. Was that a sign of leakage?

You refer to "mushy" gasket material - Do you mean this laminated composite stuff? It's pretty common lately. Were you expecting the traditional copper & asbestos type of gasket perhaps?

I'm wondering if the liners can be crack-tested also?

You are doing great so far. New rings, liner seals, gasket...
You have to do the whole head fully from here. Crack test. Planed. Valves all out, ground, stem seals etc.

Keep at it.

Re: Head Gasket. Check the Part No. I get #M808712.

Also, I see the notes -
"(NO SERIAL NO. BREAK FOR 950) (SUB FOR CH12897 OR M810713)"
and
"(GASKET HAS 10 HOLES BUT WILL WORK IN PLACE OF 8 BOLT GASKET) (SEE DTAC SOLUTION 13860)"

on the two versions of 950 listed.

Now get your dealer to print-out the Technical note called "DTAC Solution #13860".

I suspect it will just say the 10-hole gasket replaces the earlier 10 & 8 hole gaskets. But it may have more info as well.

What is the VIN number of your tractor? Can you post a photo of the VIN plate please?

Regards,
:wrench:

I'm not sure what I expected in the way of the gasket. It was my understanding that the PO installed the new head gasket and only ran the engine about an hour to find it was still getting oil in the water. I guess I expected the gasket to be 95% intact. I spent a couple of hard hours last night removing gasket material from both the head and block mating surfaces. I still have a glaze on the block that needs removed. Lacquer thinner didn't touch it. I want every bit of old material removed.

As for the picture......I see what you are referring to at the 7 oclock position of number one. I took a couple of close up pics of that area. The dark spot is of some delaminated gasket. It does look compressed but I can't be certain it was installed that way. Might have happened as I removed the head and set it back down to get a better grip. I would say at this point there isn't any smoking gun for the cause of the oil so I just keep pressing forward. After seeing the old gasket I don't have any confidence it was sealing. My guess current guess is that the removed gasket was not sealing good but there is no way to be sure.

 

[Spanner]

OK.
For Part Numbers - You are familiar with using the JD Parts Catalogue Online?

You will be looking at:

Manual: 1876 - 850 ( -16000) & 950 ( -20000) Compact Utility Tractors - 18Jun17

"Section Index"

Section: 20 - ENGINE

Page: 20 - Cylinder Head Valves and Rocker Arm (3T9OJ) (950) ( - 090299)


I give you this reference to make sure you get the correct valve stem seals.

Drop down to
Page: 29 - Piston, Rings and Liner (3T90J) (950)
to get the Liner O-Rings and Piston Rings.

Also noted rust in your waterways in the pic of the head.

Make sure you clean as much rust scale out as possible and fill with JD Coolgard Corrosion Inhibitor.

:wrench:

 

[Spanner]

Yes difficult to tell from damaged gasket. Thanks for pics though.
These new composite gaskets are a one-use-only job. (I say 'new' with some poetic-licence. They have been around for a while.)

Just wondering: You say it had about an hours running after head gasket replacement. (?)

From scraping the combustion chambers and piston tops would you say that was 1-2 hours carbon?

Also, as I mentioned above, rusty waterways is not a great look either - so soon after a head job. :2cents:

:wrench: