Generator Antifreeze change-out

[Gunni]

Was going down my list of spring commissioning tasks and noted that my generator engine (Kubota Z482) freshwater antifreeze had never been changed (installed 2009, <300hrs). Called the distributor and was told most people never change their antifreeze Really?

Apparently there is no provision to drain all of the AF on this little diesel. I am astonished. I thought AF flush and replace was a bedrock principle of good engine maintenance.

Any one have experience with the the Kubota Z482? I know some of you guys have forgotten more about diesel maintenance than I ever knew.

 

[Benny17441]

It is OK to mix new anti-freeze with a little of the old one. It will do the job it was intended for just as well.

 

[Steve Dion]

but don't be mixing different types of antifreeze. It can turn to a gel if you use the wrong type.

 

[Don S/V ILLusion]

It is OK to mix new anti-freeze with a little of the old one. It will do the job it was intended for just as well.

Be careful mixing different types.

There is a good write-up on the Yanmars web site as well as discussions in the archives showing how adverse consequences occur unless they are compatible.

 

[Benny17441]

Yes mixing different types of antifreeze can be harmful so follow the engine's manufacturer recommendation. I was referring to old and new of the same type. Good call fellas.

 

[seadaddler]

Manufactor

I know the engine is a Kabuta but do you know who actually makes the unit,if
it is a fisher Panda I could look in my manual that is on my boat and see what they say about the cooling part.
I know my manual does talking about the cooling and antefreez section but
off hand not sure what the complete instructions were,same type of cooling
system I am pretty sure.
Nick

 

[Johnb]

When I had to deal with not knowing what the previous anti freeze was I changed it with 100% distilled water the changed it again with the new mixture after running the engine for about 10 minutes.

After that I don't worry too much about not being able to drain all out since I change 5 year anti freeze every 2.5 years anyway.

 

[Gunni]

I have the manual and it has nothing in it about coolant flush and fill, that is why I called the guys who build it into a genset. What they told me was to "use the green stuff". Which I assume means the universal silicate, borate, phosphate free ethylene glycol AF. The existing AF is green, so...

The generic Kubota engine manual is equally vague.

I like the idea of multiple flushes with distilled, but the process is messy because the flush process requires removal of the freshwater hose coming out of the water pump.

 

[Don S/V ILLusion]

"Messy" or difficult shouldn't preclude doing it right. You asked...

 

[Benny17441]

I was reading up a bit and it seems like the problems of chemical reaction or gelling from mixing different types of antifreeze are being overblown. I had heard about possible problems in the late 90's but it now seems that all types of antifreeze are sold without any special warnings and the incidence of reported problems is nil. It seems the worst that can happen is that the long life of the 5 year antifreeze can be reduced to two years when mixed with the shorter life one. There is really no color standard that manufacturers are obligated to follow and I can understand why some may be tempted to dye their cheaper products yellow or red to get away from the usual connotation of green being the traditional cheaper product. I still thought like many that it was really bad to mix different types but things change over time.

 

[Gunni]

Think you are right Benny. I have a recent jug of Prestone 50:50 Pre-mix in the garage, tradition green ethylene glycol that claims to be a 5 year antifreeze. Got it to top up das auto when we were stranded with low AF far from the autohaus. They insist on blue stuff, but when push went to shove they owned up that the Preston is just fine, if not Bavarian blue.

 

[Stu Jackson]

Blue and green maybe OK. I've read some horror stories of pink and green causing severe clogs. Anyone else remember those stories, not so long ago either.

 

[petersea]

I may be wrong but I would be very very surprised if there is not a engine block drain somewhere and in a last case resort remove the lower coolant hose to drain.
Use a shop vac to drain into and maybe mess won't be so bad. Maybe use the shop vac itself to drain the system from the fill if you can, not sure how good that will work but it may be worth a try............Just a thought........


OK found a link to kubota engine manual for z482 shows a engine block drain located near dip stick. This was a pump application not a generator but I would think very similar as it is same model. http://www.fire-pump.com/pdf/engine-manuals/Kubota/21hp-DSL-MR(Kubota-engine).pdf

see section 10 manufacture advises not to mix types of coolant, further down is service section with diagram of engine and will show engine block drain.

 

[Steve Dion]

I would not mix'um.

http://autos.aol.com/article/coolant-color/


I also would only use what the mfg. suggests. There had been some issues in the past (don't know if it is still an issue).

 

[Gunni]

I may be wrong but I would be very very surprised if there is not a engine block drain somewhere and in a last case resort remove the lower coolant hose to drain.
Use a shop vac to drain into and maybe mess won't be so bad. Maybe use the shop vac itself to drain the system from the fill if you can, not sure how good that will work but it may be worth a try............Just a thought........


OK found a link to kubota engine manual for z482 shows a engine block drain located near dip stick. This was a pump application not a generator but I would think very similar as it is same model. http://www.fire-pump.com/pdf/engine-manuals/Kubota/21hp-DSL-MR(Kubota-engine).pdf

see section 10 manufacture advises not to mix types of coolant, further down is service section with diagram of engine and will show engine block drain.

Thanks Peter, the generator builder removed the Kubota block drain in order to shoe-horn the raw water plumbing into place. My only option is to remove the water pump hose, and catch the coolant before it drains to my bilge. I plan to use the shop vac to manage the situation, and will start with my oil extractor up top.