Chet P Posted May 11, 2021 Share Posted May 11, 2021 Help!! Last Saturday when we started out from Erie, PA, the coach started to overheat. I managed to limp to Buffalo, NY to Pacific Power products, the Detroit engine shop in the area. (I have a Detroit series 60 powering our Monaco Signature.) First the thought was stuck thermostat - wasn't a problem. Then the water pump was suspect - wasn't a problem. Then we replaced the wax valve that controls the radiator hydraulic fan - wasn't the wax valve. It turns out the fan hydraulic motor turns at slow speed when the system is cold, but will not speed up when the system gets hot. This was after 10 days on the road in route to Rochester to see our son and PA to see daughter. Naturally Monaco used several different hydraulic motors, so the failed one must be removed to get the part numbers off it. Calling around and talking to some knowledgeable folks hasn't been encouraging. Seems the main source of these pumps has been England. Colaw in MO says they have no used pumps. They are always getting calls for them. Visione says maybe,( have some on the shelf) but wants a photo and part number, which means removal of the existing pump. For the record, the coach is a 2004 Signature that has the 500HP Detroit series 60 motor. If anyone has had a similar experience, I'd sure appreciate any comments, thoughts, or ideas where we might get a pump in a reasonable time. I would love to hear from you. Chet P 2004 SIG towing a Tesla in a trailer Link to comment Share on other sites More sharing options...
bpperk Posted May 11, 2021 Share Posted May 11, 2021 White House hydraulic in Scotland is where I got mine for my 2004 signature. I have the old pump and a rebuild kit. I can supply you with a photo of the pump for the part number or I can provide the used pump. It was working fine when I took it off proactively. With the rebuild kit it should be fine. 3 Link to comment Share on other sites More sharing options...
Frank Bergamo Posted May 11, 2021 Share Posted May 11, 2021 (edited) Chet, there is a switch valve on the fan motor that may be your problem. I replaced the switch valve on my 02’ Marquis when having problem with fan turning wide open at cold running temperatures. It turned out that the thermo/wax valve was bad and not the switch valve. The part number for the fan motor is 551-1-01303-210. White House Products is where I got both the thermo/wax valve and the switch valve. I still have the old switch valve if you can not locate a new one. Hope this helps. Edited May 11, 2021 by Frank Bergamo Correction on part number Link to comment Share on other sites More sharing options...
timaz996 Posted May 11, 2021 Share Posted May 11, 2021 I agree with Frank. I also had to replace my wax valve when my fan was not running correctly. It’s easy to test by disconnecting both small hydraulic lines off of the valve and capping them with brass plugs. Running the engine with these two lines capped will run the fan wide-open. Good luck with solving the issue. Tim Link to comment Share on other sites More sharing options...
John Haggard Posted May 12, 2021 Share Posted May 12, 2021 Your advice above is right on. If your hydraulic motor is not leaking and runs slow when cold. It's probably good. Change your hydraulic fluid and hydraulic fluid filter if you haven't recently. I change mine annually. Yes, overkill. But I have never had any pump or hydraulic motor issues. I have two hydraulic motors with two fans. Good Luck Keep us posted. Link to comment Share on other sites More sharing options...
waterskier_1 Posted May 12, 2021 Share Posted May 12, 2021 I agree with Tim. Test the fan first before ordering a new one. Remove the two hoses from the wax valve on the radiator. Cap each hose and start it up. Fan should run max speed. Then couple the two hoses hoses with a double ended fitting, the fan should run at minimum speed. If this works, it is likely the thermo-wax valve that is bad. They are known to fail, but when they do they are designed to fail with maximum fan speed, not minimum. Link to comment Share on other sites More sharing options...
David K Posted May 12, 2021 Share Posted May 12, 2021 We have the Cummins engine in our Scepter (2003 40PST). Last fall we started the engine to leave and had no power steering. The cooling fan would run fine. We have the Sauer Danfoss hydraulic pump. After much testing, we determined the two stage pump was not putting out any pressure from stage two. Using a cosmetic mirror and a cell phone for photos (and the bathroom mirror to reverse the backward image), we were able to get the part number for the pump. After much research, I ended up connecting with John Davis (contact information below). As you said, the pump is manufactured in the UK. John has a special relationship with the manufacturer which speeds up customs considerably. The rebuild kit for the pump had a longer lead time than getting a new pump. We ordered a new pump. It took over six weeks to get the pump even with overnight shipping and expedited customs. When we removed the old pump and took it apart, we found the second stage had failed. I am afraid our experience was a very long wait for a pump. John Davis RV Services Inc PO Box 3564 Lapine, Or. 97739 cell 1-541-693-3015 Office 1-541-306-6473 jdrv1@yahoo.comhttp://www.jdrv1.com/index.html Link to comment Share on other sites More sharing options...
Paul J A Posted May 12, 2021 Share Posted May 12, 2021 (edited) 17 hours ago, Chet P said: Help!! Last Saturday when we started out from Erie, PA, the coach started to overheat. I managed to limp to Buffalo, NY to Pacific Power products, the Detroit engine shop in the area. (I have a Detroit series 60 powering our Monaco Signature.) First the thought was stuck thermostat - wasn't a problem. Then the water pump was suspect - wasn't a problem. Then we replaced the wax valve that controls the radiator hydraulic fan - wasn't the wax valve. It turns out the fan hydraulic motor turns at slow speed when the system is cold, but will not speed up when the system gets hot. This was after 10 days on the road in route to Rochester to see our son and PA to see daughter. Naturally Monaco used several different hydraulic motors, so the failed one must be removed to get the part numbers off it. Calling around and talking to some knowledgeable folks hasn't been encouraging. Seems the main source of these pumps has been England. Colaw in MO says they have no used pumps. They are always getting calls for them. Visione says maybe,( have some on the shelf) but wants a photo and part number, which means removal of the existing pump. For the record, the coach is a 2004 Signature that has the 500HP Detroit series 60 motor. If anyone has had a similar experience, I'd sure appreciate any comments, thoughts, or ideas where we might get a pump in a reasonable time. I would love to hear from you. Chet P 2004 SIG towing a Tesla in a trailer Contact; sourcerv.com for their resolution to your problem. I know it's not the wax valve, but they may be able to help . If you have a coach with the Sourer-Danfoss hydraulic fan drive and have experienced failures related to the electronic control unit known as the "FDCA" we have an economical answer to the problem. When these controllers fail, the fan typically will go to full speed and will not modulate; creating several undesired effects. The pilot valve (wax valve) system in this kit is time tested, extremely reliable, and more efficient than the electronic FCDA. http://sourcerv.com/images2/conversion.png Edited May 12, 2021 by Paul A. Link to comment Share on other sites More sharing options...
timaz996 Posted May 12, 2021 Share Posted May 12, 2021 When my wax valve failed the fan ran slow. That's why I had the over temp problem. Link to comment Share on other sites More sharing options...
Chet P Posted May 14, 2021 Author Share Posted May 14, 2021 This has sure been a costly experience for me. The first diagnosis was stuck thermostat, then water pump, then wax valve, then fan motor and finally the hydraulic pump shaft coupler and pump. Turns out the pump and shaft stripping was the whole problem. I now have a complete rebuilt fan motor, a hydraulic pump, a wax valve, and a Detroit 60 water pump. as spare parts. After 10 days in the shop, we hope to get back on the road Monday or Tuesday next week. 1 Link to comment Share on other sites More sharing options...
Recommended Posts
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 accountSign in
Already have an account? Sign in here.
Sign In Now