Fan / Thermostat

Barryh · Jan 31, 2016

I have been slowly doing maintenance to my PT getting it ready for spring. I Just cleaned out the gas tank and installed new filters and gas hose. I am cleaning the carb and have a new fuel pump on the way. Also just bought a new marine water separator with filter the same setup that came with the Kohler. Of course could not get the original they stopped making them but the new one works perfect.

I have been watching for the hydraulic cooler fan to come on while the tractor sets idle. So far have not seen it kick in. How long before it is suppose to come on after the engine is running idle?

I hooked the old fan up directly to make sure it still works. It does so if it's not coming on guessing this is the thermostat and I will need to order a new one..

How many of you have just wired the fan up directly so it is always on.. I would think the fan would burn out quicker this way but would keep the hydraulics and engine cooler thinking I like that idea better.

Any one done this and how did work out. Not sure where I can get another fan, my guess I will have to modify with an upgrade this one when it burns out..

davesl708 · Jan 31, 2016

The hydraulic fluid may not get hot enough to need the cooling fan when at idle. Working the hydraulics should warm the fluid up and you can test the temp sending unit to see if it is still working.

cqaigy2 · Jan 31, 2016

Maybe hit the sensor with a heat gun?

Barryh · Jan 31, 2016

davesl708 said:
The hydraulic fluid may not get hot enough to need the cooling fan when at idle. Working the hydraulics should warm the fluid up and you can test the temp sending unit to see if it is still working.

I checked it after using it for a few hours lifted the steel lid and it was not spinning. Not sure if it had been running and cut off or not wouldn't be able to hear it with the tractor running.. Not a big deal though, as long as I know the fan still works. I'm sure I can find the part somewhere.. Thanks for the reply

Barryh · Jan 31, 2016

cqaigy2 said:
Maybe hit the sensor with a heat gun?

I took apart the wire connectors and they were fairly loose. I cleaned them and put them back on tight. Waiting on a fuel pump right now as soon as I get her back up and running. I might try that if it still does not come on. Thanks..

joshlee · Jan 31, 2016

I have the subaru engine and the White Rodgers heat relay opens up at 110 degrees, I think. To run the fan continuously I don't think would be a good idea, because that oil temp has a sweet spot. Being too cold causes more friction, so the oil heating up isn't a bad thing. So having the fan turn on at the right time according to how the engineer designed the hydraulic system would seem the way to go, to me.

Barryh · Feb 1, 2016

joshlee said:
I have the subaru engine and the White Rodgers heat relay opens up at 110 degrees, I think. To run the fan continuously I don't think would be a good idea, because that oil temp has a sweet spot. Being too cold causes more friction, so the oil heating up isn't a bad thing. So having the fan turn on at the right time according to how the engineer designed the hydraulic system would seem the way to go, to me.

Think I will just pull it out and find another one online.. Makes sense thanks..

Scrambler82 · Feb 1, 2016

As said even the new electric fans in cars don't run all the time.
If they do then you need to check them out.
Find out what the working temp is and get some water, heat it to that temp and see if the thermostat conducts electricity, if so then it isn't the it.
Then find out working temp of oil, see if it matches the working temp for the thermostat.
Why buy new if what you have is working.
Also, if the working temps of the thermostat and the oil are not matched or you want to lower the on temp, then consider getting a thermostat with a different working temp range.

woodlandfarms · Feb 1, 2016

I don not have your machine but in the winter I am hard pressed toget the cooler fan to run unless I am stump grinding or something serious with the hydrualics (which would be a million post holes or mowing).

joshlee · Feb 1, 2016

Yeah, same here. Mine doesn't turn on hardly at all. One of the things I would like to ask an engineer down at tazewell is, what is the leveling off temp for the hydraulic oil on the PT-425s ? Just out of curiosity.