Engine Coolant

[37chief]

About 15 years ago I purchased my JD 401B. The head gasket was replaced by the guy i got it from, and had water in the oil. After some detective work I found one of the cylinder liners had a pin hole. I replaced the liners, and pistons. now I am using JD Cool Guard coolant. Was the original hole in one of the liners from no coolant? I have heard of clavation. What causes that? After a complete motor rebuild it has been a great tractor. I would hate to see water in the oil again from something that could be prevented. Stan

 

[used red MN]

Read this
Cylinder cavitation
Your JD dealer and probably NAPA will have a test kit to check if the protection level of the coolant is adequate, it can degrade over time. They will also have the additive to restore the strength of it.

 

[moresmoke]

The additives in coolant that prevent cavitation, and corrosion for that matter, are depleted by chemical reactions over time. As said above, the coolant can be checked and replenished. You can also change out the coolant and start over. Be sure to use a coolant that is designed for diesel applications. Deere Coolguard is good, has been replaced with a newer formula. Be cautious of mixing different coolant chemistries.

 

[Janicholson]

Cavitation is a physical property of liquids in high velocity interaction with solid objects. A simple example is a boat propeller that is turning faster than water can stay in contact with the front surfaces of the blade. This actually causes a high vacuum to be formed as the water is pulled away. This vacuum is now (remember this is a high speed thing) pulling on the surface the water went away from. this can actually pull molecules of metal away from the surface, As the "bubble" of nothing (vacuum) collapses, it allows the water to smash back into the metal with smacking force. This again causes atoms of material to be dissociated from the parent propeller blade. The cylinder sleeves in an engine (especially diesel) are subjected to high pressure pulses from diesel fuel combustion. This pressure is transmitted from inside to outside of the sleeve. as sound. The sound we hear standing next to a diesel is a remnant of that noise. The sound transmits through the Iron liner at almost 5000 meters/second. In air sound travels 340m/s. This actually has the effect that the sleeve vibrates (bigger and smaller) with every firing impulse. This motion is capable of creating that same Bubbling cavitation discussed in the video. The damage is intensified by the fact that the cavitation bubbles form in the same location over and over resulting in the creation of holes completely through the sleeve. The conditioners mentioned in the other threads are designed to eliminate, or radically limit, the formation of the bubbles of vacuum. I hope this helps. Jim

Propeller Cavitation
Cylinder in cavitation.

 

[rustred]

and i will add, in caterpillar class years ago they highly specified to make sure u have a good rad cap and keep the coolant under pressure was the biggest thing. keep them bubbles tiny caused by the exploding diesel fuel on the power stroke.