A good cleanse for the radiator and engine is granulated CITRIC acid. Mercedes recommends this for their cars. I used it on my B7400 that I had and the radiator and block came out spotless. It is also NOT harsh on any of the metals or radiator tubes.
Thermo-siphon systems, cooling systems with out water pumps, can work pretty well. You putting 50/50 coolant actually hinders the heat dissipation of the coolant via the radiator. Research about coolant ratios with thermo-siphon systems and I believe the maximum recommendation of coolant is 20%, 80% water. There are products out there called "Water wetter". Other important factor is not over loading the tractor and keeping the engine RPM up in the higher ranges to keep the fan working well. Make sure the fan drive belt is properly adjusted.
I had an old B5200D 4x4 the the 500cc two cylinder diesel. I used it to run a 48" bush mower and it did quite well. It would occasionally spew some coolant while working it hard. So I would stop, disengage the mower, bring up the RPM and let it cool down. I believe some of the real early Kubotas had a whistle on the radiator overflow so when they steamed, the whistle would alert the operator.
Thermo-siphon systems, cooling systems with out water pumps, can work pretty well. You putting 50/50 coolant actually hinders the heat dissipation of the coolant via the radiator. Research about coolant ratios with thermo-siphon systems and I believe the maximum recommendation of coolant is 20%, 80% water. There are products out there called "Water wetter". Other important factor is not over loading the tractor and keeping the engine RPM up in the higher ranges to keep the fan working well. Make sure the fan drive belt is properly adjusted.
I had an old B5200D 4x4 the the 500cc two cylinder diesel. I used it to run a 48" bush mower and it did quite well. It would occasionally spew some coolant while working it hard. So I would stop, disengage the mower, bring up the RPM and let it cool down. I believe some of the real early Kubotas had a whistle on the radiator overflow so when they steamed, the whistle would alert the operator.
