Coolant for Kubota G1700

[hermit]

I have just bought a used Kubota G1700 diesel garden tractor (D662 engine) with low hours. I have no service history so I will replace all fluids etc. It will be used for mowing and light towing with low hours each year. I want to keep it for a long time and aim to change the radiator coolant every other year and flush now and again. I would really appreciate some advice on engine coolants. I have read around the subject and believe Kubota recommended basic green coolant J1034/J814c. This is getting less easy to source in UK so I am thinking of upgrading. I have contacted BASF and they insist that a G30 OAT formula is correct for my application. I am not keen. Its seems overkill and I am concerned about compatibility in an older engine. A lot of people seem to use a hybrid G05 formula which has low level silicates and nitrites. Despite what BASF say this seems to make sense as it is the next step up from green coolant? I understand that the D662 is not 'wet sleeve' but will the nitrites protect other areas like the water pump or are nitrites unecessary or detrimental in this application? I have a shortlist and would appreciate views:

1) Comma Xstream G05 http://www.commaoil.com/productsguide/view/6/354

2) Motul Inugel expert/ultra (contains silicates but NO nitrites)
https://www.motul.com/gb/en/products/oils-lubricants/inugel-expert
https://www.motul.com/gb/en/products/oils-lubricants/inugel-expert-ultra

3) Motul also do a classic which I assume is a nitrite free green coolant? https://www.motul.com/gb/en/products/oils-lubricants/inugel-classic
http://arizonamotors.ro/userfiles/product_files_shared/MOTUL%20INUGEL%20CLASSIC%20-25%C2%B0C%20ARIZONAmotors.ro.pdf


Thanks in advance

 

[Donald]

I would assume a G-05 or JD CG II would be fine for your use. You will need to do a good job of flushing the old green with distilled water before you add new coolant of a different chemistry.

 

[hermit]

Thanks for the reply Donald. Yes I can get hold of CGII at the local Deere dealership. What are your thoughts on silicates coming out of solution?

Are the OATs in CGII safe for this engine. I understand that 2-EHA is not present but what about the others?

 

[roadrunner1]

CoolGard/CoolGardII is not only safe for your engine, I am not aware of an engine it isn't safe for as Deere back-specced it in their legacy engines.

 

[doitmyself]

WOW, I feel for you hermit. There is only conflicting information out there.

According to this site, http://www.tractordata.com/lawn-tractors/001/4/5/1454-kubota-g1700.html your tractor was made between 1989 and 2000, so we are talking somewhat old technology in regards to OEM coolant? , gaskets, etc..

The boys at tractorbynet.com claim that all/most Kubotas are not wet sleeve and that the old conventional IAT green coolant is good enough? You say this is hard to find in the UK.

I agree that G05 is probably the next step up without going OAT and/or 2EHA. The Valvolene G05 has a light diesel rating. In my opinion, I would definitely stay away from the 2EHA.

Then we jump to the new JD Coolgard II which is nitrite free and heavy duty tri-OAT, designed for global use (no nitrite) and the newer HD egr engines, but back compatible with the older/lesser regular Coolgard. The Coolgard II states it is safe for ALL engines, including gasoline, making one think it is generally safe.

This old thread from 2009 questions the use of these heavy duty OAT formulas in "older" engines. http://www.bobistheoilguy.com/forums/ubbthreads.php/topics/1696012/1 It "suggest" that even being 2EHA free, the heavy oat formula might not be compatible with "older" engine designs.

Of course, it is all speculation, as indicated by my frequent use of quotes and question marks. I used the old Coolgard in a 25hp compact Kubota for about 10 years and a John Deere/Kawasaki engine commercial mower. It "seems" that you don't need to worry so much about cavitation, but that old BITOG thread speculates that the Coolgard II might be so much overkill (old engines) to maybe have a bad result too.

Whatever you do, flush that old stuff out REALLY well to avoid chemistry incompatibility. It's the age of your tractor that makes this more of a dilemma than it should be. That, and Kubota's lack of updating their fluid recommendations since forever.

I hope others chime in.

EDIT: I tend to overthink things...maybe roadrunner is correct!

 

[hermit]

Hi doitmyself, thanks for the reply. I think you have summarised things well. It is REALLY frustrating when there is so much conflicting information out there and the manufacturer is no help! I also overthink things but once decided on I can leave it alone and move on!

Anyhow, I'm a bit reluctant to switch to something radically different than old original green if that was ok. It seems to me the best way is to move up to the next level of coolant rather than leap to the latest OAT formulation. That is why I was unhappy with the BASF recommendation and am uneasy about CGII. I understand that CGII is a great coolant, but I doubt it was developed with other applications in mind even if Deere do say it is virtually universal. It would be a leap of faith. Also I have read that OAT formulations can take 5000 miles to fully protect. Well my Kubota will never get there so I prefer some silicates.

If cavitation is not an issue in any part of these machines, then I am leaning towards the Motul Expert Ultra above. I think it is a HOAT and uses both silicates and OATs. Maybe the OATs in it will cover cavitation issues due to the loss of nitrites? It says that it is fully compatible with other MEG coolants so no worries about cross contamination and it has a whole raft of approvals including Cummins, Volvo, Perkins, Case and MAN. Doesn't seem too shabby. Also if it has to go to a dealership for work then if some tech tops up with green I'm not looking at an incompatibility problem!

 

[Trav]

I have been using the CGII in a 1999 B20 without any problems, it has the 3cyl diesel.
I bought it in 06 and ran CGI in it till about 4 years ago when I switched it over to CGII. I will put the CGII in the new BX25 when the time comes.

 

[hermit]

As an update I have received some tech advice from both Motul and Comma. Motul say that both the Inugel coolants listed above are based on glysantin G48 and contain 2-EHA. That puts me off using them.

Comma provided the following comments on their G05 product:

"If the original handbook requested ‘green’ then this suggest a silicate type coolant should be used like the Xstream G48. Xstream G05 does indeed contain silicates and nitrites- the nitrites are there to help prevent cavitation seen with some heavy duty diesel engine applications. Considering your application, I suggest either the G48 or G05 would be suitable."

"we can confirm G05 does not contain 2-EH. Typically we do not recommend mixing our coolants with other brands as we cannot guarantee the performance. However, in theory G05 should be compatible with a silicate type coolants...we recommend flushing the system through with water."

I am now leaning towards the Comma product. Perhaps one of the experts on here could clarify:

1) Is nitrite desirable, undesirable or of no consequence in my application?

2) If someone tops up G05 with an old spec green or new OAT coolant what will be the consequence.

Thanks

 

[Garak]

I can't answer your first question, but I would avoid topping up with anything of a different chemistry, and would go for a very good flush before switching chemistries.