Gjac wrote:
...Try the simple things first before you change the fan clutch.
The fan clutch isn't simple???
It's already out. I either have to clean it and put it back in or put in a new Hayden in for about 55 bucks delivered.
Also...
if it were the radiator, thermostat or anything else... if not completely blocked... wouldn't I see the heat register on the gauge?
I know this rig like the back of my hand. I noticed this change in clutch behavior on easy driving in fairly mild weather on straightaways. It has never acted this way before. Yes, it would come on when we hit the hills on a warm day, just like it should, and the gauge reacts accordingly... like clockwork. Until now.
So even if the gauge was failing, I know by history when the clutch would normally engage. And now it's engaging much earlier and sometimes remaining engaged for long periods even after the gauge has dropped way below normal levels.
And it was a sudden change. It didn't do this on the 5 hours to the campground and the 5 days of driving around. It only made this dramatic change about a third of the way back home. I would think a dirty or dirty-ing radiator would cause a more gradual change in the clutch behavior. This was sudden.
Also... Hayden calls fluid in the bi-metal spring an "obvious sign of failure."
http://www.haydenauto.com/upload/HaydenAuto/Documents/Cat_Hayden/Hayden%20Fan%20Clutch%20Design%20Types.pdfAnd...
My research indicates that the fluid loses viscosity over time and the clutch may spin too slowly when disengaged, i.e. the engine may run a little hotter than it should and the fan may be forced to cycle under more moderate driving conditions when it may not normally need to engage at all..... possibly.
Another expert says they basically last forever. Hence my lack of a decision as of yet.
Thinking out loud...
Perhaps the call is to buy a new Hayden and install it. As usual, I will keep the old unit on the rig as a spare. It's a relatively simple roadside procedure. And what's another bloody knuckle or three among friends.
