Pushing antifreeze

[ShadyShag]

I bought a B7100 hst-d new style at auction.
Anti freeze was low, I added 1 quart so I thought the radiator was leaking but it’s actually pushing it out of the overflow tube.
do these 16hp 3 cylinders blow head gaskets, or is it likely to have a cracked head?

 

[North Idaho Wolfman]

Could be as simple as a bad radiator cap.

These aren't known for "blowing" the head gasket.
And a cracked head will not normally just push it back to the radiator.

If your not getting white smoke and / or very hard starts very unlikely a head issue.
Pull the radiator cap run it and look for bubbles, lots of bubbles.

You can also pull out the injectors and know right away if you have a coolant issue.

 

[Runs With Scissors]

Love that exhaust

 

[Lencho]

How full was it after you added the quart? They need a little room for expansion. If
I fill mine to the top it spits out the excess. If you look inside after it cools, is it back to the level it was before you added? Welcome, and good looking tractor by the way.

 

[ShadyShag]

Love that exhaust

Stock one was rusted out and the old StreetGlide take offs fit the bill! Just high enough I done get smoked out.

How full was it after you added the quart? They need a little room for expansion. If
I fill mine to the top it spits out the excess. If you look inside after it cools, is it back to the level it was before you added? Welcome, and good looking tractor by the way.

How full was it after you added the quart? They need a little room for expansion. If
I fill mine to the top it spits out the excess. If you look inside after it cools, is it back to the level it was before you added? Welcome, and good looking tractor by the way.

It always looks full but after work it.. I can usually add over a quart
Someone spliced an inline water heater, so if that is gummed up it could boil the antifreeze in the head.

 

[Russell King]

Not sure if this applies to your tractor but…

Kubota used thermosiphon systems (with no water pump) on several of their engines. Then people would add in line pumps to “help” that system. That was not needed and usually made things not operate correctly. All that was needed was better maintenance on a clean radiator (inside and outside). Some people added overflow bottles but not the correct type of radiator cap.

That system WILL eject fluid from the radiator overflow hose until it is happy, usually the upper tank is about half full (or empty) and then no more fluid is ejected.

So see if that is really a heater or a pump in your hose. If a heater that is fine, if a pump then you should consider removing it and restoring it to thermosiphon.

There are illustrated parts list at KubotaUSA (or whatever country you may be in should have one available) that are very helpful in seeing how your tractor was originally.

NONE of this could be applicable to your tractor though!