The 2006 Beaver Monterey utilizes a Sauer Danfoss wax valve to control the hydraulic fluid which drives the side radiator cooling fan .  Mine started leaking hydraulic fluid, slowly at first and grew worse over time.   Had it replaced and found the valve is now out of production.  The part number is:
Sauer Danfoss 5553/1/09857/210.  In order to procure one, it had to be pulled of the Monaco production line.  Sounds like many of the coaches will in time need this wax valve replaced.  We'll need to come up with an alternate replacement.

Tom Crowley