G5200 Overheats Help!

[w4bss]

Hello to all, I hope someone can help me with my Kubota.
I have a 1990 G5200 with 480hrs on it. It started running hot back in the summer. Since then I have replaced the Waterpump, Thermostat, Radiator, Radiator cap, Radiator Hoses, Head Gasket and Head checked for cracks etc. We did pressure tests and checked the timing. After all the new parts and a very empty wallet, it still runs hot. It runs right at the edge of the red on the gauge and will sometimes push water out the overflow hose. This has been a great mower over the 20 years we have owned it but im fighting a losing battle.
Im open to all suggestions.

Thanks for the help,
Brandon

 

[leonz]

Did the cooling system get flushed?

Is the thermostat of the right temperature range?

It sounds as if the cooling galleries are plugged with sediment.

How tight is the water pump belt? The water pump should
have an 1/8 of slack.

 

[xtruckerbob]

We have a G3200 that we bought new in 1983 and it does the same thing. I have found on ours that if I slow the RPM down just a bit (maybe 250 or so) it will cool down to 3/4 on the gauge. It has been this way since 1990. It still mows its share of 7 acres a week alone side our L160 John Deere. :thumbsup:

 

[Redneck in training]

Check the temperature gage. Buy $15 infrared temp meter and check the temperature of the block in visinity of the sensor.

 

[Gator6x4]

Sorry about your problem. My only suggestions would be to check the belt that drives the water pump, is it slipping? Another item to check is the fan. Was it re-installed correctly? I had a friend that chased a heating problem for two weeks one time and in the end found he had inadvertently reversed the fan when installing.

 

[jinman]

If all belts are tight, I think I'd be looking at replacing the water pump. At least take it off and inspect it for excessive vane wear. Here is water pump illustration from Kubota's illustrated parts catalog.

EDIT: Oops! I don't know how I missed that the water pump was first on your list. Disregard. . . .

 

[RaisedByWolves]

Guages and senders can be inaccurate as **** and I would not replace parts simply by trusting a $15 25yr old guage.


Unless your blowing steam or large quantitys of water out of the overflow you may not actually have a problem.


I made an overflow tank for my G4200 to keep the rad filled and to check levels before startup as I didnt like Kubotas cheap steam whistle setup.