[AT] Back (D Case stuck)

[Spencer Yost]

*********** REPLY SEPARATOR  ***********
On 11/12/2004 at 9:05 AM bwhdon wrote:
>on the coolant, being no expert on it at all I was wondering does
>anit-freez allow rusting? I know water can cause oxidation . Hopefully
most of us are
>using anit freeze in our tractors in the winter?


Not pure antifreeze obviously but any anti-freeze that has had water mixed
with it(all of us a 50-50 I suspect) will rust metal if the water gets
separated(mainly) or rests on naked steel and exposed to open air.
Cooling systems are not exposed to air and the rust inhibitors are for
tying up available oxygen in the water - they will not prevent contact rust
in situations exposed to air.  You can see coolant mixtures causing rust
very nicely when you remove a cylinder head and don't remove/wipe up any
splashed coolant.  Splash a few drops of 50-50 coolant mixture from the
head into the cylinder, think nothing of it and you will have a rust spot
tomorrow.

In rust lock-ups caused by coolant leaks, here is what happens:  An engine
is turned off and a leak starts slowly dripping into a warm cylinder.  The
warm cylinder evaporates a bit of water from the coolant mixture.  Then the
air in the cylinder reaches 100% humidity as it cools and the metal
surfaces then condense the vapor and the water is now separated.   The
condensation runs back down and either stratifies under the coolant or runs
away from it if the amount of coolant mixture is small and doesn't cover
the entire top of the pistons and rings (other side of the piston or
whatever).  The water runs down along the pistons and viola.  Rust and
galling start.

Very small leaks and running-only leaks combined with a regularly used
tractor don't exhibit this but a head gasket leak that is more than tiny on
a tractor that sits may exhibit this.   Again, it would take a while to
really lock it up but enough to make it "pop" loose?   Might not take too
long.

Of course, now that we know the valve situation I doubt it is anything but
the valve.

Spencer Yost
Owner, ATIS
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