No bubbles in radiator when engine is cold but bubbles when hot.
Is there a manner to determine if it is a blown head gasket
or liner perforation due to cavitation without tearing hte engine.
% chances head gasket ?
% chances cavitation ?

Thanks in advance

Bart

Blown head gaskets are extremely rare on those tractors. Cavitation is not likely on a 2000. If it really was cavitated, it would likely be turning the oil into mayonnaise.

The bubbles could simply be from coolant agitation, or possibly even a leak on the inlet side of the water pump. I would confirm any pressurization theories with a cooling system pressure tester before I started tearing the head off.

Another way to see if it's really pressurization is by routing the overflow tube into a jar of water and looking for bubbles. You will get some as it warms up, but should stop once it reaches peak temp.

Hi Bern, Thank you for your reply...your replies to me were very helpful in the past
I greatly appreciate.

When cold: antifreeze is 2 inches below the radiator neck.
I already installed an overflow container same as in cars. When warming up the thermostat opens so I can feel warm upper radiator hose
and the temperature gauge indicates around 185 no bubbles no overflow.
Suddenly when blowing snow the temp gauge falls to 0 and antifreeze
begins to go slowly to the overflow jar in 15 to 20 minutes the jar is full
and there are bubbles and the upper radiator hose is cold.

It is the symptom of a stuck closed thermostat so last summer I intalled a new
thermostat and before installation I boiled it in water and checked with a candy thermometer
to be sure it opens a the right temperature a new radiator was also intalled.

Some days I can clean my driveways and farm yard with the snow blower the temperature gauge stays normal and no overflow. I'm realy lost on that one.

Thank you for reading

Bart

Sounds like a thermostat issue to me. If it was a blown head gasket, it wouldn't decide on which day of the week to act up, it would do it all the time.

I got to thinking more about this. Given that you have an early model, chances are greater it could be a head gasket. I would not rule it out. If you had a 2600/3600, my original thinking would stand.