4720 Coolant Leak

[Red Horse]

My skidloader (2010 JD320D) uses the same engine and was leaking around the water pump. I had to remove it and reseal it with RTV (no gasket). It is easy to remove and replace the water pump. no problems after that.
My 2012 4720's water pump started squealing, so I had to replace that one (same engine). That kit came with a paper gasket. That also was an easy fix, but the pump was close to $300.00
You definitely should pressurize the cooling system when it's cold, so you can see where its leaking.
It also could be the timing chain cover like others said. Of course that is a fairly involved repair.

Thx Arlen-After about an hour + plowing, while I started out with the tank at the proper "cold" line I'm down to a half inch in the recovery tank. And it does leak when off...Nothing of course you can see source of just by tilting hood. I'm assuming at the very least this has to start with pulling radiator.......

Stay tuned

 

[arlen4720]

Thx Arlen-After about an hour + plowing, while I started out with the tank at the proper "cold" line I'm down to a half inch in the recovery tank. And it does leak when off...Nothing of course you can see source of just by tilting hood. I'm assuming at the very least this has to start with pulling radiator.......

Stay tuned

I would pressurize it first. On a cold engine, it becomes obvious where the leaks are.
There are many test kits to choose from, and they don稚 cost that much given how much work they save by pointing you to the source quick.
Amazon.com : radiator pressure test kit

 

[Red Horse]

UPDATE
Well I put about an hour on it today cleaning up from this weeks snowfall. I had filled recovery tank to cold level before I started and it was down a half inch when I parked it. I also tightened bottom hose before I started. The bottom radiator hose was wet and was steaming. I could also see steam coming off the back side of the pump-so I'm thinking the shaft seal is leaking and the fan is just catching it and it ends up on hose. The engine also has the "green" discoloration in that area below the pump. Went to JD Parts and looks like you can't buy the shaft seal. Shocker huh!

 

[arlen4720]

UPDATE
Well I put about an hour on it today cleaning up from this weeks snowfall. I had filled recovery tank to cold level before I started and it was down a half inch when I parked it. I also tightened bottom hose before I started. The bottom radiator hose was wet and was steaming. I could also see steam coming off the back side of the pump-so I'm thinking the shaft seal is leaking and the fan is just catching it and it ends up on hose. The engine also has the "green" discoloration in that area below the pump. Went to JD Parts and looks like you can't buy the shaft seal. Shocker huh!

You may just need to reseal the gasket surface. If you take the tension off the belt you will be able to tell if the shaft has play or is binding. You won’t like the price of thee new water pump! Mine lasted only 1300 hours.
It’s an easy repair at least.

 

[tom4120]

Oldtimer66,
I am right in the middle of doing this on my 4120. When you put the new metal embossed gasket on, did you put it on dry, or put any sealant/dressing on it? The kit I bought from Deere did not have any instructions.
Thanks

 

[jkflatt]

Hoping to resurrect this thread and get some advice. My JD 4720, cab tractor w 1300 hrs appears to be leaking from the water pump, almost appear to be leaking from the gasket area but not sure. i‘m wondering what has to be removed to access the bolts to replace the water pump? If it is just leaking at the gasket, given the time To remove and repair, should I just replace it w 1300 hrs on it? Also are the aftermarket water pumps decent quality compared to the OEM?

 

[beenthere]

Hoping to resurrect this thread and get some advice. My JD 4720, cab tractor w 1300 hrs appears to be leaking from the water pump, almost appear to be leaking from the gasket area but not sure. i‘m wondering what has to be removed to access the bolts to replace the water pump? If it is just leaking at the gasket, given the time To remove and repair, should I just replace it w 1300 hrs on it? Also are the aftermarket water pumps decent quality compared to the OEM?

jk
What is the difference in price between OEM and the aftermarket water pump you are looking at?

 

[jkflatt]

jk
What is the difference in price between OEM and the aftermarket water pump you are looking at?

$425 oem w core exchange from Deere, $150 aftermarket.

 

[oldtimer 66]

I would suggest you get new bolts. They are a torque turn design. Plus the gasket

 

[jkflatt]

I removed the water pump today. Had to remove the radiator, shroud, and fan to get one bolt on the pump removed. I thought it strange that there was no gasket on the old pump. (?) seems like I’ve read about others that didnt have a gasket either. the replacement pump and gasket should be at the dealer tomorrow. So should I use rtv sealant on the gasket also?