Kioti CK3510HST antifreeze?

[Amvcane]

wish I was smart enough to splain it to you Lucy.....all I know is that when working the snot out of the machine coolant is all over the outside of the overflow tank collecting pasture clippings and dirt.....heh...so that's about as scientific as ah can gets....
oh and when the unit cools the level is low....maybe some shade tree engineer can splain it to the both of us in layman terms.....lol....

YLee, does your expansion tank have a hose coming from the radiator to the bottom of the tank, and an overflow hose going from the top of the tank directed to the ground? Or does the tank just have a cap on it and the antifreeze overflows through the cap threads? A slot in the male threads of the tank, so the system breaths.
This is a pic of my CK 35 expansion tank. Just a cap. After getting tired of cleaning and filling the tank I went to my dealer and found that some tractors on the lot had a tank like mine and some had a overflow hose coming out of the tank neck.
I ended up letting the tank burp as much as it wanted till it no longer overflowed. It settled just a little bit above the minimum line and has been there for 5 years now.

 

[justman777]

wish I was smart enough to splain it to you Lucy.....all I know is that when working the snot out of the machine coolant is all over the outside of the overflow tank collecting pasture clippings and dirt.....heh...so that's about as scientific as ah can gets....
oh and when the unit cools the level is low....maybe some shade tree engineer can splain it to the both of us in layman terms.....lol....

Not sure this explanation is simple, but just about every liquid expands when it's heated. I've always called it thermal expansion. Believe this is because the atoms and molecules are more "excited" and move around more at higher temperatures. This increases the distance between them, and the liquid "expands". The lower the temp, the less "excited" the atoms and molecules are, so they're closer together and makes the liquid denser. When your radiator is full and your thermal expansion tank is filled appropriately, you'll notice the tank always has a bit more room in it. That's to leave space for the coolant to expand. As the coolant warms up and expands, it will also increase the pressure on the radiator. Your radiator cap has a seal/spring on it that opens when the pressure exceeds the strength of the seal/spring, and allows coolant to flow into the expansion tank. This allows the pressure in the radiator to return to normal. This happens continuously when the engine is running. When you stop the engine and it cools down, the coolant in the radiator starts to contract and creates a vacuum. The vacuum pulls coolant from the expansion tank back into the radiator.

If you get too much thermal expansion or something else is pressurizing your cooling system, you'll have more coolant flow into the expansion tank than it can handle and it'll overflow. That's how you get your low fluid levels. That is, if you don't have a leak somewhere else.

You may want to check your radiator cap to see if it's working properly. It should maintain a certain amount of pressure on the cooling system to keep the boiling point of the coolant higher. If it's weak, it may not be keeping pressure, and letting more coolant flow into the expansion tank than it should.

I know that's not terribly simple, but that's basically what happens...at least from my understanding!

 

[YLee Kioti]

YLee, does your expansion tank have a hose coming from the radiator to the bottom of the tank, and an overflow hose going from the top of the tank directed to the ground? Or does the tank just have a cap on it and the antifreeze overflows through the cap threads? A slot in the male threads of the tank, so the system breaths.
This is a pic of my CK 35 expansion tank. Just a cap. After getting tired of cleaning and filling the tank I went to my dealer and found that some tractors on the lot had a tank like mine and some had a overflow hose coming out of the tank neck.
I ended up letting the tank burp as much as it wanted till it no longer overflowed. It settled just a little bit above the minimum line and has been there for 5 years now.

View attachment 645525

Last August cut about 8 acres of an elderly rancher's place. The old cattle pen veggie was to the top of rear tires and the open graze area was about halfway up the rear tire. On the second day the temp gauge went past the normal op. indication. Let it cool off and then went back to work. by day's end indication moved towards the red zone again.
When offloaded at home the tank level was below the minimum line and the tank was covered with debris caked to the tank.
So that's what I based my comment on. (note, yeah forgot to take blower to keep radiator clean)

So mine has the radiator overflow hose to the cap and a second overflow to the ground.
The tanks look clean (well sorta) since I hosed it down hard after a cutting session.
You can see how it collects dirt/dust as coolant seeps around the cap. I thought it was normal since it's been that way since day one.
level is about an inch from the full line indicator.

Have not been able to work it hard enough to see it lose any level, yet.
Should close the loop with this.

 

[VictorW]

I just wonder if the overflow tank is just to small for the fluid expansion contained in the engine and radiator. I need to compare the fluid quantities between the tractor and my truck which has a tank that's at least 6 times the size. Just a thought as to why my tank might end up almost empty after a good workout.

 

[Amvcane]

Vic, with the tank I have there is a sponge under the cap that stays moist with all the sloshing around on my property. The pressure differential between the tank and atmosphere will push the fluid in the sponge out the slots in the tank threads. I think maybe a baffle in the tank would reduce this.
It is possible the tank is to small, though myself, I have never seen the level above the max mark when very hot after extended use.
Glad to see some of the chrome hood lettering CKs still going.

 

[PhantomOfHeat]

The one coolant I have been using for years in my TDI is sierra antifreeze. I ran it for two timing belt changes at 100% no water I added 2-3oz of water wetter the year I decided to keep the grill completely blocked only left the inter cooler uncovered. I'm still running 100% but no water wetter (it did make a difference in temps) just never added it and I have only kept the top blocked.

The nice thing about sierra antifreeze is it is non-toxic. They sell it at Ace hardware by me.