Hydraulic wax valve fan

[Jeff753]

Is there a way to test the functionality of these fans? It seems mine might run full speed all the time. Hard to tell. When I first start up its running quite fast. Can you test it with the engine off by checking resistance or continuity?

[jacwjames]

I had the same problem, I have a 2002 Windsor with a 350 HP 8.3 ISC.

Jeff, do you have the thermovalve controller that is mounted on the radiator??

It looks like this & has 2 #6 hydraulic lines to it.
Sauer Danfoss Thermal Valve 553/1/09857/210**: nwrvsupply.com

If so yes it can be tested so you can tell if the valve is working correctly and/or the motor speed controller isn't working correctly.

If you have the thermo valve go buy 2 plugs and a union.

Take the lines off and plug both lines and see if the fan runs wide open.

Then put the union in the 2 lines and see if the fan runs at ideal.

If does this the motor speed controller is working as it should and chances are your thermo valve is bad.

I purchased my thermo valve from White House Products, cost was ~$265 including freight and exchange rate.

The part # was 553/1/09857/210, took ~1 week to get after ordering. There should be a tag on your thermo valve with part #.

[oldmattb]

Is this a change from previous behavior?

Our 98 Windsor fan seemed to run very fast on start-up. Source Engineering explained that there was an intentional restriction in one fitting, to make the fan run on start-up. This is to allow cooling air to the dash AC condenser to reduce back pressure.

We rarely use the dash AC when we start. On the advice of Source, I drilled out the restriction. It was in a removable brass fitting, and had a small pathway inside.

I removed our wax valve and bench tested it. It was very hard to get to. I had to grind a socket to paper-thin, and grind away some of the radiator to get it out. All-in-all about a half day job just to get the valve removed.

Matt B

[Jeff753]

Originally Posted by jacwjames

I had the same problem, I have a 2002 Windsor with a 350 HP 8.3 ISC.



Jeff, do you have the thermovalve controller that is mounted on the radiator??



It looks like this & has 2 #6 hydraulic lines to it.

Sauer Danfoss Thermal Valve 553/1/09857/210**: nwrvsupply.com



If so yes it can be tested so you can tell if the valve is working correctly and/or the motor speed controller isn't working correctly.



If you have the thermo valve go buy 2 plugs and a union.



Take the lines off and plug both lines and see if the fan runs wide open.



Then put the union in the 2 lines and see if the fan runs at ideal.



If does this the motor speed controller is working as it should and chances are your thermo valve is bad.



I purchased my thermo valve from White House Products, cost was ~$265 including freight and exchange rate.



The part # was 553/1/09857/210, took ~1 week to get after ordering. There should be a tag on your thermo valve with part #.

I seemed to recall a posting from Mike C about doing this with the hydraulic lines. I can do that when I get home. I wondered if there was an electrical test to see if it was functioning without disconnecting hydraulic lines. Does fluid run out when you disconnect these lines?

Having said that I have the 3 filter Nelson hydraulic reservoir and it is about due for a filter change. What do we use for hydraulic fluid for these fans/power steering systems? I will get the filters and change them when I check out the motor speed controller using the method you suggest.

How do you test the thermo valve? I don't know if my fan is running full speed or not.


Jeff
2001 Dynasty Regent tag axle
Cummins 350 8.3 ISC
2012 Jeep Grand Cherokee Overland
FMCA U60 Task Force Chairman

[jacwjames]

I had a radiator replacement last year, road debris punched several holes in it. Crosspoint Cummins did the work.

When I got the coach home I noticed that the fan was running WAO, I could hear the roar. In the past it would only run at high speed when I was pulling a good hill and temps climbed, and only noticed if I pulled off the hwy and did a walk around with the engine running. It did not run high RPM much.

I have a Silverleaf monitor and I started looking at what temp the fan would start to run at high speed, and it started as soon as the thermostat opened at 180 F. It was not suppose to start running higher RPM until temp reaches 185 and the ramps up to WAO once it reaches 197F.

I contacted Monaco and they recommended doing the tests, which basically show that the speed controller on the motor is working correctly. If it is working correctly then it narrows it down to the thermo valve. Don't know of a way to test, I guess you could connect some lines to it with water flowing through and put it in a bucket of water and heat up and see at what temp it opens/closes.