Where is my thermostat?
Stupid question right?
Here's the problem. The Kubota L175 is overheating. Last time I mowed I started to hear a whistling noise that can easily be misinterpreted as a squeaking noise, like a deck bearing. I realize the noise continues when the clutch is depressed and the PTO and deck are not turning. I realize it is overheating. Unfortunately, there is no gauge or idiot light.
When I park it, I could hear water boiling in the engine for a little bit. So I figure the problem is not a bad radiator cap that is blowing off water too easily. However, now that I think about it, I guess in theory, it could blow out enough water, that it becomes low on coolant. THen it would overheat.
Anyway, I let it cool down. Wipe the grass off the radiator screen and add coolant. Mow for another hour and it starts to overheat and whistle again. I'm thinking thermostat. I go to look for it and can't find it. I look for a waterpump and cannot find that either. There is a radiator and fan but the fan is mounted to a bearing and that is it.
I look in the owners manual that has a parts breakdown, and there isn't a waterpump or thermostat.
WHAT THE HECK???
Radiator. Fan. No waterpump. How does water circulate through the 2 cylinder diesel engine without a water pump? Why is it overheating?
BTW, after looking at the parts list, I find there is a whistle at the end of the radiator overflow. So when it gets hot and blows off some stem, it blows the whistle.
Here's the problem. The Kubota L175 is overheating. Last time I mowed I started to hear a whistling noise that can easily be misinterpreted as a squeaking noise, like a deck bearing. I realize the noise continues when the clutch is depressed and the PTO and deck are not turning. I realize it is overheating. Unfortunately, there is no gauge or idiot light.
When I park it, I could hear water boiling in the engine for a little bit. So I figure the problem is not a bad radiator cap that is blowing off water too easily. However, now that I think about it, I guess in theory, it could blow out enough water, that it becomes low on coolant. THen it would overheat.
Anyway, I let it cool down. Wipe the grass off the radiator screen and add coolant. Mow for another hour and it starts to overheat and whistle again. I'm thinking thermostat. I go to look for it and can't find it. I look for a waterpump and cannot find that either. There is a radiator and fan but the fan is mounted to a bearing and that is it.
I look in the owners manual that has a parts breakdown, and there isn't a waterpump or thermostat.
WHAT THE HECK???
Radiator. Fan. No waterpump. How does water circulate through the 2 cylinder diesel engine without a water pump? Why is it overheating?
BTW, after looking at the parts list, I find there is a whistle at the end of the radiator overflow. So when it gets hot and blows off some stem, it blows the whistle.
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it's in the hall next to the bathroom! 0 -
On my L3400 the waterpump is right behind the fan pulley. I assume the thermostat is where the top hose enters the engine.
It has one... Make sure your belt has the right tension to turn it.
http://www.bare-co.com/files/kubota/kb4.htm0 -
I keep telling you, man.
They make special rectal thermometers. You can lose the other kind too easily.0 -
Cold water goes to the bottom of the radiator, hot water goes to the top of the engine. Natural convection current carries the water through the system (think of the old "gravity flow" hot air heating systems)
You might have a air bubble that's stopping the flow of water through the engine, or you might have a damaged headgasket (any sign of water in the oil, or white smoke from the exhaust?).0 -
quote:Originally posted by select-fire
On my L3400 the waterpump is right behind the fan pulley. I assume the thermostat is where the top hose enters the engine.
It has one... Make sure your belt has the right tension to turn it.
http://www.bare-co.com/files/kubota/kb4.htm
That would be the logical location if I only it was there.0 -
quote:Originally posted by Tailgunner1954
Cold water goes to the bottom of the radiator, hot water goes to the top of the engine. Natural convection current carries the water through the system (think of the old "gravity flow" hot air heating systems)
You might have a air bubble that's stopping the flow of water through the engine, or you might have a damaged headgasket (any sign of water in the oil, or white smoke from the exhaust?).
Natural convection is my guess. It doesn't sound like a good system to me.0 -
quote:Originally posted by select-fire
On my L3400 the waterpump is right behind the fan pulley. I assume the thermostat is where the top hose enters the engine.
It has one... Make sure your belt has the right tension to turn it.
http://www.bare-co.com/files/kubota/kb4.htm
Waterpump #2 looks like the style that is in the parts manual for Group 2. But Group 1 does not have a waterpump. Other than this difference, the Group 1 and Group 2 Engines are pretty much the same.0 -
Didn't you look at the link and see the part. It has a pulley on it. Pulley handles the belt. Follow the belt and find the pump. It is there you just haven't found it yet. Call your Kubota dealer. 0 -
Am I going to have to take a picture? 0 -
Trade it in for a newer one... 0 -
quote:Originally posted by select-fire
Trade it in for a newer one...
I turned that one down last month.
Besides My dad still mows with an Allis-Chalmers B. Grandpa bought it on an auction when it was 1 year old.
A Kubota from the 70's should be that old yet.0 -
IIRC, it's called a thermosyphon system. Some old tractors used this type- no water pump. I use a kubota occasionally thats the same style, can't recall the model #. Make sure that the radiator fins are not plugged.Lots of material can get thru the screen and cut airflow thru the radiator. I use a water hose to reverse wash out the trash fairly often. hope this helps. 0 -
That old Allis B will still be around when your Kubota is junked!
I love those old ACs......my dad has several.
Merc0 -
quote:Originally posted by Mercury
That old Allis B will still be around when your Kubota is junked!
I love those old ACs......my dad has several.
Merc
Father In Law had a Kubota L175 and L185. They are basically the same except the 185 is newer and has drop boxes at the end of the axles to the wheels. This allows higher ground clearance without raising the total tractor height. He sold the 185 and kept this one. He thought those gear boxes at the end of the axles are a weak design.
Allis-Chalmers B's are running strong and never have a problem with the same design.0
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