Hydraulic fan blasting away

[llib enad]

Stakealot

My wife and I have a 99 Allure that we took factory delivery November 24,1998 and have been fulltiming in it since. We boondock about 85% of the time. When we pulled off the pavement a HUGE dust cloud would follow us. Cut a piece of cardboard to fit the grill trying cut down on the dust. with the engine at idle when the cardboard was within 3 inches ,it was sucked to the grill. After about 3 months of this ,my wife contacted Doug Rutherford at CC. Seems the air conditioning company wanted a high volume of air over the radiator.Doug said the remedy was to enlarge the male orface that connects the hydraulic hose to the fan controller. Both the in and out units were drilled. can not remember the size bit that was used but was only a small increase in size. No more dust and still going strong after 130 thousand plus. Hope this will help.

Bill

[chasfm11]

Thanks for the additional description. It is a shame that the maker of the control doesn't give you more information. For example:

- Is the difference between the "cold" and "hot" sensing done by the thermovalve just a reduction in volume or a corresponding increase in pressure? If it was the latter, you could try putting some sort of a pressure gauge after the valve to see the exact effect that it was having on the fluid. I'm sure that there are fluid engineers on this forum that could explain how that actually make the fan run faster. My poor little mind cannot wrap itself around that, given the understanding that I have so far.

Part of the problem here, like in several other parts of RVs, may be that the manufacturers involved don't want to give away any "trade secrets". I was having a problem with my RV speedometer and went to Allison to find out where the speed sense data left their transmission controller. It was like pulling teeth but they finally gave me the pin coordinate. If someone actually knew the different pressures or flow rates after the thermovalve in your system, they might be able to steal the design. The lack of that kind of information is what makes parts swap jockeys of the techs who work on our stuff.

Charlie

[Stakealot]

Bill,Thank You so much for responding to this thread! I can't tell you how good it is to hear from someone with a CC that has experienced the same problem!! I KNEW there was some sort of restriction!! This makes perfect sense, If I tried to bypass the thermovalve, using the existing hoses, the fitting on the switching valve would restrict the flow!!! The orifice on the fitting, on the switching valve is VERY SMALL, as is the fitting on the thermovalve itself. So if I bypassed the thermovalve, using the existing hoses, IT WOULD STILL BE RESTRICTED!..I can't hardly sleep... Thank YOU Bill! and you're welcome to stay in my yard in NORTHERN Minnesota (with 50amp) if you're ever in the neighborhood. S