Question about coolant system

[new2diesel]

Hello community,
On my farmpro 2420 with the TY290 engine I keep having an issue with my antifreeze coolant dripping/flowing out of the overflow tube on the radiator. I don't have a ton of info to give other than I assumed it was the thermostat so I replaced it. The closest I could find was actually a couple degrees C cooler than the previous. The problem seemed better but after an hour or so of mowing with my 5ft finish deck behind me coolant is gushing out again. I tried taking the thermostat out altogether but no change. I'm fairly certain the fan is working properly because when it starts to get warm the temp gauge creeps up and goes back down in cycles. I do not have this issue when pulling a non PTO attachment. So one thing I was wondering was when I fill the radiator I fill it cold until I can see fluid near the top. There is no overflow tank. Is this correct? Is there anything else I should be looking at?
Thanks for the feedback.

 

[HankC]

There is no overflow tank, you are correct. Therefore if you fill the radiator to the top and the coolant heats up from tractor use it will overflow as it expands. It has no where else to go except overflow. Expansion is a function of temperature so the hotter the engine/coolant gets the more it expands and the more it will drip out. As long as you're not loosing all the coolant I wouldn't worry about it. Check the level of the coolant after the engine cools down following some heavy work and make sure it stays at that level after subsequent tractor usage. The only other thing that can make coolant blow out the radiator is a blown head gasket, but this would happen pretty quickly.

 

[Bob Rooks]

You can install what is correctly called a coolant recovery system (available at auto parts stores for about $12.). This allows the coolant that was expelled due to expansion to automatically be drawn back into the cooling system when it cools down. The whole point of this is to eliminate air in the system and increase cooling efficiency. Air does not carry away heat from the cylinder and head components like coolant does. "Coolant" is the term used for a water/anti-freeze/anti-boil mix, or a water/phosphate additive mix.

 

[greg_g]

If you've got an OE radiator cap, it can't hurt to replace that too. The OE caps weren't known for a good seal, which also contributes to "burping" issues like this.

//greg//

 

[RonMar]

Yep, replace the thermostat(one for the correct temp) and add a coolant recovery tank. Here is how I did mine, but I combined it with an air filter re-location, so you will have to find a different mounting location scheme. The tank I used is from napa and is a good one I have used for several generator projects.

AirfilterCoolantRec

The thermostat is important in a diesel. Too cool a running temp will cause excessive carbon buildup and can also cause excessive lube oil dilution as unburnt fuel condenses on the cylinder walls more easilly in a cold/lightly loaded engine, and gets past the rings to collect in the crankcase. With the thermostat installed, the temp gauge should warm to the thermostat temp and stay there. Two exceptions to this are:
1. In really cool temps, the ammount of coolant leaking past the thermostat and the abundance of cool air passing thru the radiator will keep the temp gauge from reaching the thermostat temperature. That is why big rigs have coats zipped up over the grill in the winter, to tailor the available cooling to the heat generated so the engine runs at the correct temperature to avoide the aforementioned issues. I hang a hand towel over part of my radiator when working in the winter to keep the temp gauge up at normal thermostat op temp.
2. You say you were mowing? Are the radiator air passages clear? These will clog with fine grass and dust and reduce the ammount of available cooling to the engine. You will start out mowing at normal temp then the gauge will slowly creep up above the normal thermostat temp as the radiator cloggs and looses cooling. To make this easier to clean I wrapped the radiator guard with aluminum window screen to act as an easy to clean pre-filter and catch the fine stuff. When mowing in the dry, I have to knock the junk off this screen every couple of houres. For a more indepth clean I use an air blowgun with a 2' long air pipe made from an aluminum arrow shaft. It has a hole drilled in the end to blow air perpendicular to the pipe. I can slip this pipe down behind the radiator to blow the dirt and dust back out the front, as the radiator shroud on mine has little openings at the top rear corners that allow me to reach the entire radiator rear surface. You can see pics of the screen wrapped inlet guard plate in the above link. Try some compressed air, I think you will be amazed at how much crap comes out of your radiator from brushhogging, I get a bunch out of mine, even with using the screen so I use the air every so often during the mowing season or if I have trouble maintaining thermostat temp.

P.S. do not use water to spray out the radiator air passages. The mass of water under any real velocity can bend and really mess up the delicate air fins in the radiator core...