Kubota L3940 HST - Radiator Capacity vs Cooling System Capacity

[artf]

Doing coolant replacement yesterday, I realized Kubota published specs for L3940 cooling system is 8.7 quarts, but radiator is less. This is an issue trying to get 50/50 coolant/water mix when you can't completely empty the cooling system. After the flush, I added just under a gallon of coolant, topped off radiator with water, and then filled small overflow tank with water to "High" mark.

What is the L3940 HST radiator capacity?

I'm happy with the tractor, just trying to get squared away for next year's maintenance. It was easy to service except for refilling SuperUDT. I did not get to the fuel filter change before dark and did not want to try bleeding it by flashlight. I'll replace it when I get it back in the shed.

 

[YLee Kioti]

Do you have access to the T-stat?

If yes, then drain fully. Maybe even place a rag around the T-stat housing and insert a blower nozzle at about 5 or 10 psi to push water out of the cooling jackets down to the lower radiator hose and to finally drain out.

Seems all machines have Initial fill capacities that we will never attain in routine drain and refill maintenance activities.
Example, for my machine hyd. fluid is 11.8 gallons, but a full drain and refill was 10 gallons.

So as long as you did a good flush and fill then run machine long enough to heat up and cycle T-stat.
Monitor for a few days to see where level sits and adjust accordingly.
I just did wife's 4Rnr and it was the same drill, stated capacity not even close to drain and refill.

 

[Leejohn]

I think you had better run the tractor for 20 to 30 mins then re check to see how low of temp the cooling system is set for. By reading you post and you using 50/50 mix and adding water to top off I would guess the temp is not set low enough for where you are at. The only time I would even use 50/50 mix would be if I had also drained the block or just to top off a system that was set below freezing. Do you have a anti-freeze tester?

 

[4570Man]

The exact mixture isn’t critical. Just use a cheap tester to make sure the mix is suitable. Be sure to run the tractor to circulate the mixture before testing. Put some in your freezer if you don’t trust the tester. I’d bet there’s another gallon in the block. Assuming you flushed it and what was remaining was straight water I don’t think you have enough antifreeze. Also make sure you’re using straight antifreeze not that pre diluted crap.

 

[SDT]

Doing coolant replacement yesterday, I realized Kubota published specs for L3940 cooling system is 8.7 quarts, but radiator is less. This is an issue trying to get 50/50 coolant/water mix when you can't completely empty the cooling system. After the flush, I added just under a gallon of coolant, topped off radiator with water, and then filled small overflow tank with water to "High" mark.

What is the L3940 HST radiator capacity?

I'm happy with the tractor, just trying to get squared away for next year's maintenance. It was easy to service except for refilling SuperUDT. I did not get to the fuel filter change before dark and did not want to try bleeding it by flashlight. I'll replace it when I get it back in the shed.

I drain all that I can (most engines no longer have block drains, but certainly look for one) and refill with concentrated anti freeze and distilled water.

I estimate the amount drained and refill using a quart graduate. One quart anti freeze, one quart D water, etc., until full. I usually remove the surge tank for cleaning and refill it to the full mark with concentrated anti freeze.

SDT

 

[YLee Kioti]

For those that perform as much maintenance as possible this is a worthwhile investment.

Amazon.com: 4-in-1 Refractometer Ethylene Glycol, Propylene Glycol in antifreeze liquids freezing point temperature and freezing point concentration, automotive and industrial battery liquid,by Hamh Tools: Home Improvement

The cheap auto retail shop tester with a simple float is well a rough estimate.
So decided to upgrade to this. Used it on 4Rnr recently and satisfied.

It's the same type we used in our motor pool to maintain our fleet.

 

[mikester]

Unless you have a lot of machinery to service Pre-mixed coolant saves a lot of time

 

[SDT]

Unless you have a lot of machinery to service Pre-mixed coolant saves a lot of time

Agreed, but I am yet to see any premixed coolant that labels distilled water on the label.

I do not put tap water in any of my cooling systems.

SDT

 

[4570Man]

Agreed, but I am yet to see any premixed coolant that labels distilled water on the label.

I do not put tap water in any of my cooling systems.

SDT

It cost the same amount per jug which in the end cost you twice as much. And if you’ve got a gallon of straight water in the system adding another 8 quarts of 50/50 antifreeze isn’t going to be enough.

 

[gimmodog]

trying to get a 50/50 mix after adding unmixed antifreeze to you tractor is only a guess at what mix you will have. When you buy a gallon of unmixed antifreeze use an empty antifreeze gallon jug and premix to 50/50 before putting any into the tractor. This will take the guesswork out of your mixture.