B7400 green sludge

[a3dhunter]

First off, brand new to the forum. Had this kubota b7400 for about 4 months. Use it mostly for mowing 2.5 acres.
Today while mowing a bunch of white steam burst from under the hood.
I shut it down immediately and it hissed steam for about a minute and i could see green antifreeze on the front axle. I figured a blown hose, but when inspecting I couldn't find a hole/split in the hose.
I pulled the lower hose off and found a thick green sludge in the hose and coming out of the radiator.
I'm thinking this is just a radiator failure and only had about 15 minutes to look around for problems.
It appears there may be a trans cooler in the radiator? Anyone familiar with these?
Could an internal failure have caused the green sludge and problem?
Appreciate any input, thanks.

 

[Russell King]

Could that be oil that was mixed with the radiator fluid?

Did you check what the crankcase oil looked like?

 

[a3dhunter]

Could that be oil that was mixed with the radiator fluid?

Did you check what the crankcase oil looked like?

Yes, oil was black and full, no contamination and not low.
Thanks.

 

[NorthwoodsLife]

The older Kubotas didn't have a water pump. Only thermal physics or dynamics cycled water (anti-freeze) from the engine to to radiator.

The radiator fins and radiator dust cleaning is of utmost importance.

Check your radiator. Spray it clean.

 

[Russell King]

I have never seen that type of stuff in any radiator before and really have no idea what it is but…

If the tractor has been running fine for the four months and this is the first cooling system problem here is how I would proceed:

1) get some containers that fit below the radiator hose you have removed and then pour water into the radiator top opening. See what happens with the sludge and if it dissolves in the water or if it stays “sludgy”. See how clean the outlet pipe looks after you have run a couple of gallons through it.

2) if the sludge is cleaning up then just con to pour a few gallons of water through the radiator.

3) take the thermostat out if it has one. Replace the thermostat housing.

4) put hose back on the radiator and fill it with water and see if it will stay full for a good bit of time or if it is just draining out somewhere. Look for a overflow tank if you have one and check if it’s full or empty. If empty, put water in it also and see if it holds. I would probably let it sit for overnight.

5) start tractor and make sure it is not dumping the water out. Loo in radiator opening and see if you see any bubbles or water movement through the radiator.

6) drive tractor towards the storage area and keep an eye on the temperature.

7) if it doesn’t overheat then drive it all the way to a good place to work on it and let it run for a while to see how it goes.

8) drain the water and see what it looks like. Make a decision based on that. Check the crankcase oil.

9) if it is going well (no overheating and the sludge is dissolving and the coolant drain looks okay, I would recommend getting some radiator cleaner and run it through the radiator then flush it with water a few times.

10) replace the thermostat and fill with water again and see if it runs fine and doesn’t overheat and then start to use it as normal for some of the normal chores you have been doing.

11). If all is well then you can replace the water with coolant and continue to use the tractor.

post back with more details and results as you go.

 

[North Idaho Wolfman]

That looks like someone has put stop leak (lots of it) in the system.
Flush it all out, fill it with water, and see if it overheats.

FYI: The hydraulic oil cooler is in front of the radiator not inside of it.

 

[a3dhunter]

All right guys, found the problem once i removed the radiator and turned it upside down. The upper radiator hose neck was rotted away.
I flushed the engine and radiator to see how much green jelly was there and it wasn't much.
I'll replace the radiator and move on.
Thanks