4720 Coolant Leak

[Red Horse]

My 2007 4720 has 1892 hours and after a heavy session running my chipper a few months ago I noticed a slight coolant leak. It was dropping down on tie rod and could not really see the source. Plowing snow this morning and it is getting worse. with engine running I can see coolant being blown up the top of the bottom radiator hose. Hose connection seems tight. My concern is this is coming from water pump. Looks like an expensive repair if in fact that is it and I take it to my dealer.

Anyone have any experience with a similar problem?

Sad fact is I have known the owner for a long time and he just sold all three of his locations to one of the megadealers. Not looking forward to taking it to them so if it is the pump, I may get a buddy of mine who just retired as a heavy equipment wrench and take it on myself- or should I say, I'll get him and I'll be the helper

 

[Rebeldad1]

"Hose connection seems tight. "

What does that mean? did you try to tighten them? if so was the engine cold? try tightening the clamps when the engine is hot.

clean off the area thats wet with a rag and pressurize the radiator. the leak should be easy to see if its the hose or water pump.
if you dont pressurize it it may not leak when its not running.

 

[Beaver Cove Deere]

It is well documented that the front cover attachment to the block leaks from the expansion of different materials. Mine leaks and I think they all will or do. Someday I'll have the dealer do the job but until then I keep an eye on the coolant.

 

[fried1765]

My 2007 4720 has 1892 hours and after a heavy session running my chipper a few months ago I noticed a slight coolant leak. It was dropping down on tie rod and could not really see the source. Plowing snow this morning and it is getting worse. with engine running I can see coolant being blown up the top of the bottom radiator hose. Hose connection seems tight. My concern is this is coming from water pump. Looks like an expensive repair if in fact that is it and I take it to my dealer.

Anyone have any experience with a similar problem?

Sad fact is I have known the owner for a long time and he just sold all three of his locations to one of the megadealers. Not looking forward to taking it to them so if it is the pump, I may get a buddy of mine who just retired as a heavy equipment wrench and take it on myself- or should I say, I'll get him and I'll be the helper

Get him,..... and you be the helper !!!

 

[Tinhack]

Get him,..... and you be the helper !!!

Oh man, that was cold. :laughing:

 

[Rick Gent]

My 2007 4320 had less than 1000 hrs. when the water pump let go. You can check the pump by releasing the belt tension and check pump shaft for play. My pump shaft was so loose it destroyed the impeller. All I found were pieces inside. It's not a bad job to replace if that is your trouble. Check all the easy stuff first though!

 

[oldtimer 66]

I had the same problem with my 4320 with the JD Power Teck engine 2.44L. I posted several times about this problem. The forward end cover is aluminum and the rest of the engine is cast iron. They don't like each other. It also has to do with the factory using Hylomar and not a gasket to seal these two items and the last problem is the design. There is a kit, only a couple of hundred dollars at that time /2015/ and I did this repair at about 1000 hrs ? and I now have 2100 hrs without any more coolant issues. Now it could be something else but that was not my experience. I will post a couple of pictures to show you how involved it was. It wasn't hard to do but you need to keep everything clean during this process. The oil pan weighs 55 lbs. so that part is 2 man operation. It supports one end of the front axle trunnion. If you do the work don't install the brass shim/ .020 thick, between the forward end cover and the cylinder head at the coolant connection. That just adds another possible place for the coolant to leak and this is the place where this coolant leak originates from. A couple of other things. You will probably want to replace the synthetic bearings for the front axle trunnions, one large in the oil pan and one small. All of the bolts to attach the forward cover are torque turn so you will need all new hardware and a torque turn tool dial. Last item about the design, the forward end cover should have been made of a similar type of iron, probably ductile iron. That's all I have to say for now unless I think of any thing else.

 

[oldtimer 66]

I forgot one other item about the leaking. The rubber gasket that goes up at the top of the forward end cover does not seal properly to the forward end cover. Note the cast finish where this rubber gasket locates. This is the connection point to the cylinder head. I hand filed this area flat to remove the as cast surface. This rough as cast surface I think had a lot to do with the leak at this location. You cannot file the surface down in the groove but you can file that area around it. And with the design of the rubber gasket and it's wing type of cross section this should help seal this area better. This is the area I said to not install the brass shim/ spacer that just adds another surface to leak. Also you need to check and see if you cylinder head is degraded where it connects to the forward end cover . If the cylinder head is pitted it could compromise this repair. My theory is that when the forward end cover was machined new this side of the casting was not indexed to the machine spindle. I think the forward end cover was machined on one setup, (when you look at it it can be machine on a 3/4 axis machine with a turn table), where it actually needed to be setup to machine this side of the casting. It could also be that engineering said we don't need to machine that area, it will seal with the rubber gasket. Well when you get this all apart you will understand why it leaks at this location.

 

[Red Horse]

Guys, thx for all the responses. Another good example of why this site is the best!

Oldtimer66-Nice shop!

 

[arlen4720]

My 2007 4720 has 1892 hours and after a heavy session running my chipper a few months ago I noticed a slight coolant leak. It was dropping down on tie rod and could not really see the source. Plowing snow this morning and it is getting worse. with engine running I can see coolant being blown up the top of the bottom radiator hose. Hose connection seems tight. My concern is this is coming from water pump. Looks like an expensive repair if in fact that is it and I take it to my dealer.

Anyone have any experience with a similar problem?

Sad fact is I have known the owner for a long time and he just sold all three of his locations to one of the megadealers. Not looking forward to taking it to them so if it is the pump, I may get a buddy of mine who just retired as a heavy equipment wrench and take it on myself- or should I say, I'll get him and I'll be the helper

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.