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Neglected Deere 850B service

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sawdustmaker

Well-Known Member
Joined
Jan 5, 2016
Messages
132
Location
South Carolina
I recently acquired a 1989 John Deere 850B LT dozer with 6400 hrs on the meter. It hasn't been used for 7-8 years. Owner passed. I'm Going through it and its been more neglected than just sitting for several years.
It was missing the front roller on the left side and 4 others were completely shot. I put some rollers on it so i could move it. Changed some fluids and filters. It seems strong but i havent been able to work it yet while the fan pulley is being rebuilt. I was told it had a new John deere rebuild engine not long before it was parked and the oil hadnt been changed since. It wont start without ether at 60F. The oil was really bad that i drained out, but i dont know if its got low compression or a fueling issue. Or both. The governor hunts(is sluggish. It revs up on warm startup and bounces off idle when throttled down) more than i think it should, but im not familiar with this motor. I have a leak at the parking valve and injector number 6. Do i have to have a special tool to pull this injectors?
 
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Shimmy1

Senior Member
Joined
Aug 14, 2014
Messages
4,374
Location
North Dakota
Someone pulled the rack magnet out of the fuel pump? I think you should try moving the throttle lever to full fuel before cranking, making sure to pull it back right away when it starts.
 
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sawdustmaker

Well-Known Member
Joined
Jan 5, 2016
Messages
132
Location
South Carolina
Thanks Ill get those O-rings replaced. I didn't know that parts catalog was public. That's a huge help. Thank you! I'm going to pull the parking valve off to see what parts I need for it.
What is the function of the "Automatic Control Valve"?
Does this dozer have a Cold Weather Disconnect Clutch? the repair manual says theres a clutch lever by the seat? I see nothing like this. Has the linkage been "deleted" or was that only on earlier models?
 
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sawdustmaker

Well-Known Member
Joined
Jan 5, 2016
Messages
132
Location
South Carolina
Shimmy1 said:
Someone pulled the rack magnet out of the fuel pump? I think you should try moving the throttle lever to full fuel before cranking, making sure to pull it back right away when it starts.
Click to expand...
So there's a magnet that holds the rack for starting? If I let it run at half throttle and move the throttle quickly to idle it will die. If I do it slowly it will not die.
 
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Diesel Dave

Senior Member
Joined
Sep 29, 2022
Messages
1,096
Location
Ontario Canada
sawdustmaker said:
Thanks Ill get those O-rings replaced. I didn't know that parts catalog was public. That's a huge help. Thank you! I'm going to pull the parking valve off to see what parts I need for it.
What is the function of the "Automatic Control Valve"?
Does this dozer have a Cold Weather Disconnect Clutch? the repair manual says theres a clutch lever by the seat? I see nothing like this. Has the linkage been "deleted" or was that only on earlier models?
Click to expand...
The Automatic Control valve controls the hydrostatic pumps and motors variable displacement to keep the engine from pulling down excessively when dozer is pushing a load.
The cold weather disconnect clutch was an option.
 
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