JD 870 Yanmar 3TN84 diesel in oil

[a1953mdl]

Hate to start my membership with questions, but it is what brought me here.
I have a John Deere 870 that has a Yanmar 3 cyl 3TN84 (iirc).
It is getting diesel in the oil.
I have been told this is probably from the lift pump or the injection pump.
Any ideas on how to verify which it is or which is more likely?
I started pulling the injection pump off but didn't realize you had to pull the front cover to pull the gear off the front of the pump first.
I have the factory service manual for the 870 but it doesn't cover the injection pump.
Can y'all help me.
Lee

 

[AKfish]

I have the factory service manual for the 870 but it doesn't cover the injection pump.
Can y'all help me.
Lee

Welcome to TBN, Lee. Fuel in the wrong places... fairly well sucks! I bought the JD OEM 70 series Technical Repair manual from eBay when I owned a JD 970 TLB.

Great book - extensive coverage and pretty cheap - as I recall.

But that'll take some time... so, I'd go here to get started -- https://jdparts.deere.com/servlet/c...ervlets.searchcontroller.EquipmentModelSearch

Get registered and you're off! kennyd on the John Deere Owning/Operating forum has a brief tutorial linked to his ID that is very helpful. A quick search will turn up his avatar.

AKfish

 

[paulinkansas]

I've got a Deere 830. a 3 cylinder diesel. Last year I had the same problem as you. Changing the diaphragm and gasket ($20 + 30 minutes) didn't work. Had to remove the injector pump (1 hour), have it rebuilt ($80), and reinstall it and bleed the system (1 hour). The radiator hose was in the way, and had to be replaced ($20 and 30 minutes)

My girlfriend at the time would help me with these projects on a Saturday night. We're married now, and she'd wants to learn how to operate the tractor.