JD 450C General cooling system info

[DSK]

Some various questions as I move on to addressing the coolant system next, as part of my quest to get the old crawler running again. Would appreciate any feedback.

First, what type coolant to use for this engine? The former owner used green, but I'm planning to put in Final Charge Pro Series (POAT type). Seeing this is sold for "heavy duty diesel engines" it's my best guess.

2. Thermostat - the previous thermostat is missing from the engine. I seem to remember complaints on this machine that coolant would overflow from the radiator after working a while. I'm guessing someone thought it was overheating and removed the t stat. The rad did leak slowly (which is now sent off for repair. I can't find a new unit for under $1k).
The parts diag shows 3 separate temp thermostats, 180, 192 and 205. In the end, the dealer parts rep and I decided on the cooler of the 3 as they were out of the 192 stat. It's not too late for me to return and exchange, I just don't know which it should have. So to summarize:

-Thoughts on coolant overflow after heating up?
I read on a previous post this was due in one case to an blocked elbow fitting off the water pump, but I've been able to get air through all the piping to verify it is clear. What else could I check for this problem?
-What temp thermo to use?

3. With the front of the engine accessible now that the rad is off, are there maintenance items here that should be addressed that relate to the cooling, or other, systems? I am planning to change the old fan belt. Upper and lower rad hoses are in good shape, as they were replaced not too long before the machine went dormant.

After draining the old coolant, I've run the Prestone flush thru and done multiple flushes with distilled water to get the particulates out.
This machine was sadly neglected, as evidenced by the bad state of the cooling system, so I want to get it as close to spec as reasonable.

Many thanks to whomever might lend some thoughts and help me learn more about these machines.
GJ

[LeonardL]

Your thermostat depends largely on where you are located. The colder the climate then the hotter you want your stat to be. But generally the 180 is fine and you shouldn't have any issues with using it. As for your coolant type, I would use the regular old green stuff. Mostly out of cost but if you want to go with the higher cost coolant then go for it. It's certainly not going to hurt anything.

Since you think there may be an issue with it loosing coolant, then I would use plain water first after you get your radiator back and that way if you do have an issue then you're not out of pocket for expensive coolant. Once you have established the health of your system then you can go from there.

As for thoughts on what may be causing it to loose coolant, I would replace the radiator cap for sure. These engines only run somewhere around seven pounds at the cap so since you will have a good radiator I would replace the cap at the same time. These engines tend to get rid of some coolant for some reason and I was never completely sure why but they do. I've seen guys install overflow jugs but I was never really impressed with the results. A couple of the guys had good results and the others didn't work at all. So that is up to you if you want to try it or not.

More importantly, you will need to do a system check for exhaust getting into the system. Just to make sure you don't have a bad head gasket or some other issue. Again just use plain water until you see what you have going on.

You asked about maintenance items to look at while the radiator is out? You said you will replace the fan belt and that is always a must thing to do if the belt is showing signs of being bad. You will also want to look at your water pump and make sure the bearing and seal or okay on it. Also if your machine has an oil cooler then you will need to check the lines connecting it to the water pump and the cooling system. You also need to look at the radiator mounts to make sure they are not dry rotted and or broken out at the centers.

Also a good thing to check is your hydraulic fittings at the hydraulic pump and the lines leading to and from it. It is also a good time to check anything that connects up front. Because it is a booger to get to once you have it all back together.

Other than that, it's a really good time to give the front a really good pressure washing. Dirt and debris are the worst enemies of these machines.

Hope this helps and keep us posted on your progress.

[DSK]

Thanks very much for this info.

Ok, I will keep the 180 stat.
I already have the POAT coolant on hand, but good to know that green is acceptable.
My thought exactly, I was planning to add some more flush and just fill up with water for testing.
Rad cap, check. So this coolant loss is a known problem...I will experiment with coolant levels. The manual says halfway between the core/tubes and the neck so I'll get it there and proceed with the result.
I presume you are describing the test for exhaust gases in the coolant? I will check this.
Front of the engine: yes, the fan belt is in horrible condition. I'm guessing no one wanted to change it because of the work involved.
Water pump: other than a visual inspection for damage, how can one tell if the bearing or seal warrants replacement without running the engine, with the rad being gone?
I wish I had access to a power washer. My plan is to get a pail of soapy water and scrub brush like mad all the front. It wouldn't be the first time I've Amished something like this.
Was planning on getting new rubber lines for the hyd oil cooler connections.
Rad mounts, haha I previous cut pieces of an old tire and used in place of the upper mounts. I would much prefer to have the correct equipment...

This is very helpful...Thanks again.
GJ