Cavitation.

[rja]

With large diesels there is a problem with bubbles in the cooling system that cause erosion of the block. There is an additive that used in the coolant to counteract this process. Does this Cavitation problem exsist in the small diesel motors? Rich.

 

[rbargeron]

Say more about this cavitation process - what causes it? Where is it known to happen (brand, application) I don't think I've heard of this on ag (slow-running) machinery.

 

[rja]

Do a search on this board. I found a lot of info. In short, I am going to call Kubota and ask them. The very least, I am going to change the coolant every year with their spces. Rich.

 

[nazud]

Cavitation erosion is the result of two dissimilar metals contained in the same fluid (coolant) where tiny bubbles will follow vibration, eventually eroding porous metals(i.e. cylinder liners, blocks, etc) creating pin holes in these items .I have seen this on many diesels Cat, Cummins, Mack etc. I dont know how prevelant this is in smaller diesels with wet or dry liners, but seen often in commercial applications. Our over the road tractors run a coolant filter which treats the electrolysis in the coolant neutralizing the ph imbalances. Some filters included a "sacrificial plate" which allowed the acids to eat at this softer metal instead of the cylinder liners. I have seen many arguments about coolant filters and treatments ,especially in diesel engines (about as popular as synthetic oils) but you be the judge and decide for yourself/w3tcompact/icons/smile.gif Fleetguard makes coolant filters, coolant additives and p.h. test strips to check the condition of your coolant. or you can read more at www.forddiesel.com, ot talk to any diesel part stores, they will stock nalcool and other cooling conditioners . Hope this helps you along /w3tcompact/icons/smile.gif.

 

[Anonymous Poster]

With the large number of older Kubotas around I thought that this is obviously not a common problem. I have always used a good quality antifreeze/coolant in my old thirty year old
Kubota and it does not appear to be suffering from any deterioration in its coolant system. If you are concerned about long term problems with Kubota products just look at the many machines that are several years old with many hours on the clock and you will find that problems encountered are rare once the teething problems are sorted out.

 

[allmobile]

In almost 14 years as a Kubota mechanic I've never seen it happen to a Kubota. It is fairly common in industrial Ford tractors. I'm a stickler for keeping fresh 50/50 coolant mixtures in the machine. I recommend changing it once a year and try not to use well water. It might be more common in the Fords because they see more abuse. The guys I've seen running those machines are more likely to keep topping it off with water than fixing their water consumpsion problems.

Brian

 

[art]

When I worked in a automotive machine shop what happens to the Fords was described as a forging problem and related to the sand causing thin spots that wore thru. I to have never seen the problem in a Kubota. Cavitation only happens in a wet sleeve engine to the best of my knowledge.

 

[cowboydoc]

It's definitely a problem with diesels and can effect any diesel. In all of my diesels I run the pre-charged fleetguard antifreeze that you can get at farm and fleet. Use this and change once a year and you will never see cavitation. If you really use your rigs alot do like I do get the testing strips to make sure that you are at the correct levels.

 

[allenb]

As some of the others have mentioned cavitation is a problem of air bubbles forming in the cooling systems, bursting, and chipping away the liners or water jackets. NAPA sells an additive called NAPA Kool that controls the PH and Nitrite levels of the coolant. They also have test strips to make sure you don't over or under charge the cooling system.