B5100 Belching Through The Puke Tube.

coondog · Sep 10, 2006

I don't know what's going on with this thing. About 15 minutes after I start it up antifreeze starts trickling out of the overflow pipe. It doesn't spew out like steam, just trickles. It doesn't have a temp guage so I can't tell if it's running hot but I wouldn't think it would after so short a run time. The fan belt is tight. The radiator cap is a STANT 7 lbs cap. Does anyone know if this is the correct lb cap? It may just need a new cap. Also, is there a thermostat inside of the gooseneck?
Thanks!!

Egon · Sep 10, 2006

I beleive you have what is called a Thermo Siphon cooling system. There is no water pump. The coolant circulates because of temperature difference. There is no thermostat.

The overflow tube may have a whistle on it to indicate high engine temperature.

If it is leaking fluid only look at the rad cap. If there is steam comming out of the over flow tube it will be overheated.

When was the last time the rad was drained and flushed and the surface cleaned of debri?

Thomas · Sep 10, 2006

Morning coondog.
What the mixture of your coolant 50/50??...for warmer temp useage.

coondog · Sep 10, 2006

Mixture is 50/50, or was, till I started replacing what had leaked out. I'm going to change the cap and drain the system, see if that helps. Unless somebody's got a better idea. There is no steam, just liquid dripping out.

coondog · Sep 11, 2006

Hey EGON, do you have any idea as to the appropriate pressure radiator cap to install?

LHoyer · Sep 11, 2006

According to the shop manual, it is a 13 # pressure cap. Kubota part # is 15021-7263

Inspector507 · Sep 11, 2006

coondog said:
I don't know what's going on with this thing. About 15 minutes after I start it up antifreeze starts trickling out of the overflow pipe. It doesn't spew out like steam, just trickles. It doesn't have a temp guage so I can't tell if it's running hot but I wouldn't think it would after so short a run time. The fan belt is tight. The radiator cap is a STANT 7 lbs cap. Does anyone know if this is the correct lb cap? It may just need a new cap. Also, is there a thermostat inside of the gooseneck?
Thanks!!

If you don't have a coolant recovery container and you fill the radiator completely, it will come out as the coolant expands. Especially with a 7 lb cap on a 13 lb system. The coolant recovery container will catch what comes out and as it cools down later, it will siphon back into the radiator.