2 year radiator maintenance question

[NEPA Guy]

I was looking for some clarification, on flushing the radiator and refilling.

On page G-34 of the service manual on line 4 It says to fill with clean water and cooling system cleaner, etc etc.

On page G-36 on line 6 it says When the LLC is mixed, do not employ any radiator cleaning agent….if mixed sludge may build up.

I don’t understand how it says to use a cleaning agent at first, and then it says don’t use it if I’m using a LLC. Does it come from the factory as LLC, if so should I not use the cleaning agent? Is there a way to tell if a coolant is LLC or not? I don’t get it.

I also have a question about what percentage I should use to mix. On page G-35 It says it must be under 50%, and shows a 40% info box.
So whats the best percentage to use? 40%? Is there a graph of different percentages people use to gauge the ratio?


On a side note a 1/2” flathead screwdriver worked to remove the drain bolt safely. I ended up damaging the drain bolt tip a bit originally with a 3/8” screwdriver. I ordered a JIS #3 screwdriver as some had said and it wouldn’t grip well enough on my damaged bolt head and proved unreliable. I managed to remove the damaged plastic drain bolt by pinching it with my fingers just past the grooves. It came out without any problem and replaced it with the new OEM bolt.

See attached pics of the manual for reference.

Thanks!

 

[Daren Todd]

I personally, only flush a radiator if there is an issue, such as noticing some gunk when changing the fluid. If no junk or gunk, I just refill the system with fresh coolant and move on

 

[SDT]

I was looking for some clarification, on flushing the radiator and refilling.

On page G-34 of the service manual on line 4 It says to fill with clean water and cooling system cleaner, etc etc.

On page G-36 on line 6 it says When the LLC is mixed, do not employ any radiator cleaning agent….if mixed sludge may build up.

I don’t understand how it says to use a cleaning agent at first, and then it says don’t use it if I’m using a LLC. Does it come from the factory as LLC, if so should I not use the cleaning agent? Is there a way to tell if a coolant is LLC or not? I don’t get it.

I also have a question about what percentage I should use to mix. On page G-35 It says it must be under 50%, and shows a 40% info box.
So whats the best percentage to use? 40%? Is there a graph of different percentages people use to gauge the ratio?


On a side note a 1/2” flathead screwdriver worked to remove the drain bolt safely. I ended up damaging the drain bolt tip a bit originally with a 3/8” screwdriver. I ordered a JIS #3 screwdriver as some had said and it wouldn’t grip well enough on my damaged bolt head and proved unreliable. I managed to remove the damaged plastic drain bolt by pinching it with my fingers just past the grooves. It came out without any problem and replaced it with the new OEM bolt.

See attached pics of the manual for reference.

Thanks!

I stopped using commercial radiator flush chemicals 35 or 40 years ago because I found it quite common that the water pump seal would fail shortly thereafter.

Haven't changed a water pump due to a leaking seal since.

SDT

 

[rjcorazza]

Sometimes Kubota manuals are worded very poorly. In this case I believe they are saying :
If using a flushing / cleaning agent, do so by mxing with water only, not with the old coolant or newly replaced coolant.

Don’t mix coolant types

Concentration should be max 50% and min 40%

I have never heard an oem refer to 2 year interval coolant as LLC as in your manual. My last 4 Kubotas came with standard green coolant, which was replaced with a longer interval coolant (HOAT is my choice)


Sent from my iPad using Tapatalk Pro

 

[NEPA Guy]

Thanks for the replies that clears things up a bit. I'm going to use the Kubota LLC brand to do the refill.

Cheers

 

[redfernclan]

I stopped using commercial radiator flush chemicals 35 or 40 years ago because I found it quite common that the water pump seal would fail shortly thereafter.

Haven't changed a water pump due to a leaking seal since.

SDT

Especially in cars. I have seen half a dozen heater cores start leaking in older cars that someone just had to add the cleaner and then back flush. All that build up was plugging the leaks. Drain and refill. I even have gone as far as buying the premixed stuff from the dealer. Requirements have changed through the years and the manufactures have a lot more additives to the coolant now a days. Anti corrosion, anti foam, stabilizers, modifiers, lubricants and the list goes on.
Any more, every couple of years I drain what's in the radiator and top off with factory coolant. I don't back flush or add a cleaner unless there is a problem and I have not had a problem for the last 30 years. It does not get all the coolant out but if I do it every couple of years, it changes enough of it out so that I keep the right additive mix.

 

[SidecarFlip]

Just curious... What is Kubota LLC?

 

[Bulldog]

Just curious... What is Kubota LLC?

long life coolant

 

[dlundblad]

2 year radiator maintenance with a flush is a bit of an overkill.. But I guess that depends on what the manual says too. I want to say my G's want yearly changes.

If you feel the need for a flush, I highly recommend food grade citric acid crystals. I did this to my truck after replacing the heater core since the rest of the system was so neglected by the PO. I did bypass the new core during this process though since there was no need to clean something new.

That said, chances are if you have future issues you would have had them at some point regardless. It was just rust plugging the holes after all.