Thermostat: Drilling hole/jiggle valve, ideal size for bit and how many holes?

[reinvent]

Originally Posted by S14DB

How do you plug in a clutch fan?

I think he means the silicone has drained out. I wish these fans were not on all the time. The so called slow speed must tax the electrical system during idle.

The air temperature coming through the radiator is sensed by the bi-metal thermal spring on the front of the thermal fan clutch. It expands and contracts with the change in air temperature operating a valve inside of the clutch. When cold, the silicone drive fluid is pumped from the working area to the reservoir. When hot, the valve opens allowing fluid from the reservoir to be transferred to the working area thereby increasing the fan speed. The clutch disengages as the air temperature decreases, closing the valve and allowing the silicone fluid to be pumped back into the reservoir.