Jump to content

Recommended Posts

I've noticed the fan running all the time now and  after reading several posts, I'm pretty sure it's the "wax valve" and before I order a new one I'd like to make sure I get the right one and I want the engine to run at the correct temp.  Mine dosent have any numbers on it. 2001 Exec 500 cummins....normally runs around 185° , as far as I can tell on my gauge.  I'm just repairing one thing at a time as money is kinda tight right now. 

Link to comment
Share on other sites

My fan runs at a low/idle speed at startup, not sure what RPM it is but a pretty good clip.  There's a pretty good description of how the system is suppose to work in my manual.

"When radiator temperature rises above 185° F, the wax thermovalve slowly closes
off the bypassing hydraulic fluid from the switching valve. A spool valve
begins to move in the switching valve. This directs the pressurized hydraulic
fluid to the fan motor. The higher the radiator temperature, the further the
spool valve is moved in the switching valve, providing a higher volume of
pressurized hydraulic fluid to the fan motor. Fan motor speed is increased to
meet the demand for cooling."

When I had a problem with my thermovalve the fan was running WAO, it sounded like a jet plan, when I walked outside the coach I could hear it an knew something was wrong.  I contacted Monaco tech support and they had me do two tests

  1. I plugged both lines and the fan ran wide open. 
  2. I then put a union in between both hoses and the fan ran at an idle.

Based on this they thought the it was the thermovalve, which I replaced and that fixed my problem.  I bought my thermovavle from Whitehouse products, it 2015 it was $168, it is much higher now.   The part I ordered was this. 553/1/09857/210, I have the parts page from my rig.  This may be different then yours.

Here is one listed from NWRVsupply, you might contact them and confirm if it will work on yours. http://www.nwrvsupply.com/product/553109857210.html

Link to comment
Share on other sites

24 minutes ago, jacwjames said:

My fan runs at a low/idle speed at startup, not sure what RPM it is but a pretty good clip.  There's a pretty good description of how the system is suppose to work in my manual.

"When radiator temperature rises above 185° F, the wax thermovalve slowly closes
off the bypassing hydraulic fluid from the switching valve. A spool valve
begins to move in the switching valve. This directs the pressurized hydraulic
fluid to the fan motor. The higher the radiator temperature, the further the
spool valve is moved in the switching valve, providing a higher volume of
pressurized hydraulic fluid to the fan motor. Fan motor speed is increased to
meet the demand for cooling."

When I had a problem with my thermovalve the fan was running WAO, it sounded like a jet plan, when I walked outside the coach I could hear it an knew something was wrong.  I contacted Monaco tech support and they had me do two tests

  1. I plugged both lines and the fan ran wide open. 
  2. I then put a union in between both hoses and the fan ran at an idle.

Based on this they thought the it was the thermovalve, which I replaced and that fixed my problem.  I bought my thermovavle from Whitehouse products, it 2015 it was $168, it is much higher now.   The part I ordered was this. 553/1/09857/210, I have the parts page from my rig.  This may be different then yours.

Here is one listed from NWRVsupply, you might contact them and confirm if it will work on yours. http://www.nwrvsupply.com/product/553109857210.html

I got mine from the same place back in 2017. It was all done online and including shipping via DHL it was about 200 bucks and I had it in a couple days. Great service. Although my valve failed in a different mode. It seem to be seized with the valve completely open so the fan only idle. I did the same test that Jim did to confirm it was the valve. I also keep a couple brass plugs with me so I can plug off those lines if my valve ever fails in the same mode  until I can replace it. As a note, it has worked flawlessly since I changed it out. 

Link to comment
Share on other sites

Did you or the previous owner convert it to a mechanical wax valve?

Most Cummins engines come with a Sauer Danfoss electronic controller for the hydraulic fan.  Detroit and Cat come with a mechanical wax valve controller.  

Some of us have converted from the electronic controller to the mechanical.  White House products in the UK sells an adjustable Sauer Danfoss wax valve.  You use an Allen wrench to adjust the hydraulic flow which in turn speeds up or slows down the fan.  

This is a link to a thread with lots of great information:

https://www.irv2.com/forums/f115/fan-stuck-wide-open-376611.html

Link to comment
Share on other sites

Sorry I should’ve listed the specs on my wax valve. It runs the fan wide-open starting at 195°. And I’ve never seen my engine get past 197 and normally will only reach that in the heat at the end of a long climb.

Link to comment
Share on other sites

3 hours ago, Flyinhy said:

I've noticed the fan running all the time now and  after reading several posts, I'm pretty sure it's the "wax valve" and before I order a new one I'd like to make sure I get the right one and I want the engine to run at the correct temp.  Mine dosent have any numbers on it. 2001 Exec 500 cummins....normally runs around 185° , as far as I can tell on my gauge.  I'm just repairing one thing at a time as money is kinda tight right now. 

sourcerv.com can help you.

 

Link to comment
Share on other sites

On 7/28/2022 at 11:18 AM, Flyinhy said:

I'm pretty sure it's the "wax valve"

Charles - as mentioned by some, you may want to visually check if you actually have a wax valve.  My manual said I did, but I discovered I actually had the Sauer Danfoss Controller.  If you do have the SD Controller, mine was bad and I have just retrofitted it and I can share what I did without having to install a wax valve.  All the best.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...