Coolant temp sensor

RF57

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I have a Gravely Promaster 460 with the Kubota v1305 diesel engine. The temp gauge has been reading 220 degrees or so when I mow, no matter what the air temp is. I replaced the thermostat and cleaned the radiator last year with little improvement. I may need a temp sensor or new water pump. What is the best source for those parts?
Thanks,
RF
 

Forest#2

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You might consider checking the temp with a Infrared thermometer.
 

Forest#2

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You can also use a regular thermometer and heat a pan of water to around 200F with most sensors and see what the gauge reads.
A IR thermometer is really handy for such and other things and will take fast temps tests.
I use one on Autos, Central heat air, etc.
If it's electronic type make sure that battery voltage is being regulated correctly.
Some dash gauges on equipment have a regulator that keeps the voltage at around 8-10 volts to the gauges so they don't go up and down as the voltages changes.
 

RF57

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The mower has a pusher style cooling system, where the fan draws air from the engine side and pushes it through the radiator. I wasn't getting much airflow, so I ended up making some spacers to move the radiator closer to the fan. It dropped the temp by 15 degrees or so. I'll see how it does when the weather warms up. I have pics, but they won't upload for some reason.
 

mechanic mark

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Your Kubota V1305 Diesel Engine needs attention immediately. Please do yourself a favor & not run engine until overheating issue is resolved. How many hours are on engine & year manufactured? Approximately how long was engine run at 200 F or over? Is Kubota V1305 original engine in Gravely Promaster 460?
Problem may be bearing & impeller on water pump shaft, worn out/ slipping, maybe some of you folks have seen this before. Keep us informed, thanks Mark
 
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RF57

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This is my fourth season using the mower. The Kubota V 1305 is the original engine. It doesn't have an hour meter, but based on the history I was told when I bought it, it has 3000-4000 hrs on it. I didn't notice any overheating problems the first two seasons I used it, but last year it went over 220 on the temp gauge, so I shut it down, cleaned the fins on the radiator, and installed a new 180 degree thermostat. After that the gauge would steadily rise as the mower warmed up, fluctuate around 195 as the thermostat opened, then steadily climb to 220 (which I assume was 205, since the gauge isn't reading correctly). After moving the radiator closer to the fan, it has been reading 205 (190). I pulled the water pump, and the impellers were in good shape. I'll plan on having the radiator rodded out over the winter. I wasn't able to find a temp sending unit at a reasonable price, so I'll try to rig up an aftermarket one.
 
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