Who has replaced their Hydraulic Fan/Steer Pump? Please share story/experience

[Larry Lee]

I read through all the hydraulic postings and didn't find the answers I'm looking for. Would really appreciate hearing from any folks that have had to replace their hydraulic (fan & steering) pump and why, how, where, who provided the service and at what cost. I would love to discuss the topic if at all possible over the phone too: Larry (949) 422-6018

I've been troubleshooting my hydraulic system and suspect my pump may be worn. Fan speed with solenoid dialed all in-fan not fast enough at idle. I live in Yucaipa CA 92399 ( San Bernardino) and am planning to have a flow test if I can find a reputable shop.

Much thanks in advance!!!

[Keith Moffett]

Larry, some questions
1) have you changed the hydraulic filter and checked hoses?
We had a hose from the fan to the filter go bad and it was weeping fluid through this outer skin.  This is the low pressure side so we assumed the plugged filter was putting pressure on the hose.  Right or wrong the new hose and filter did the trick .
2) is there a system description in your owners manual?  I believe that is where I found it.  The 07 doesn’t have the same controller as the 06.  It is variable speed through the fan motor as best as I recall but you want to confirm this pertains to your rig.
3) Any power steering issues?
4) any leaks at the pump?  Ours developed a leak in the separation gasket for the pump body.  I am told the pump and gasket can be replaced in about 1 hour shop time.  It is in for this right now.
Good luck

[Jerry Carr]

Larry I have been down this road, we had a catastrophic failure of our Hdy. system after a failure of the main pump 06PT after replacing both pumps, cooling fan. fan blade, power steering and the Danforth wax valve (3 of these).
 
 The wax valve may be your issue. The valve uses coolant temperature to regulate fan speed they are available in 5 degree increments from Source Engineering in Eugene, OR.

 We had the major work done in AZ after the breakdown and tow to Massey Diesel ( Tom is no longer with them a big loss)
What temp are you running has the coolant temps been getting higher?

The valve is not expensive and may be a good starting point. I remember that Tom did temporarily remove the valve to check for high speed fan operation. 

If you pump is really the problem you can have them rebuild it.     

[Larry Lee]

Hello Keith & Jerry! Thanks for your input. Jerry-I did come across your thread and couldn't start to imagine what you went through with that catastrophe. All hoses and connections are dry, the switching valve on my rig is controlled by the ECU and I can "unplug" the solenoid and take it out of bypass manually. When the rig is hot and sitting still power steering starts to go away due to low pump pressure. The slightest increase in RPM brings it back. Removed, inspected and tested the solenoid-all OK. I did turn the solenoid adjustment "in" to allow more flow. It has helped. Changed the fluid (AW46 5 Gallons) and scoured the tank for any debris-very clean but fluid looked discolored. Found Zero metal shavings. I'm planning to do some fan speed testing and will report back. At idle in my driveway- if I hold a paper towel against the outside radiator intake it will not hold the towel against the rig. As engine RPM's are manually increased it definitely does hold it so fan speed is increasing. At 1800 RPM's the fan does speed up and "roars" which is good. However I think the fan is still not spinning fast enough leading me to suspect he pump flow may be weak. Note: this testing is with the solenoid NOT in bypass mode-solenoid de-energized-so full pressure to fan.

Still Looking for referral for a  flow test in Southern California. Thank you again everyone!

[Roy Warren Co-Admin]

Larry,
Years ago we had good luck with Colton Truck Repair in Colton, CA.  Sorry have no other info, but I am sure you can Google it.
Roy Warren

[Larry Lee]

Hi Roy, Colton is very close to where I live and I've spied RV's there recently. Will check them out. Thank you!
PS: I think we met at the very first Rally at Newport Dunes about 8 years ago.......? Hope all is well.

[Eric Maclean]

Roy
In my opinion most truck repair facilities are not equipped or trained to make accurate diagnosis on complex hydraulic circuits.
As your coach uses a single pump to run both power steering and cooling fan it will have a priority valve in the system that gives priority to the steering system in the event of insufficient flow situations for safety reasons it also incorporates a fan motor with a bypass system which in your case is controlled via a solenoid valve by the engine ECM depending on coolant and air intake temperatures to control engine coolant temperature and charge air temperature .that's why these system requires a different approach to diagnosis.
I believe your on the right track with pump pressure and flow however there are several things that can effect those such as filter or hose restrictions and even cavitation caused by lack of hydraulic  fluid to the pump  or suction side  starvation.
Or even a stuck bypass valve or pressure relief valve at the fan motor dumping the system pressure back to the reservoir so you can see a good diagnosis is critical to avoid expensive unnecessary repairs.

My suggestion would be to contact a good hydraulic shop in your area and see if they could sent a mobile repair tech to your location to do a full diagnosis on the system and determine your course of action.
They will likely be able to remove and repair the effected component or have access to a new replacement as well

Before having anyone look at it it is important to get as much information as possible on your particular system so the tech can reference that information to understand what they are working on and more importantly how it's supposed to work.

Hope this helps
Eric

[Daniel Stricker]

I'm new here so forgive me if I break forum etiquette.  So Larry,  did you find anyone to assist you with your hydraulic pump issues?  I nearby in Coachella and I am having the same issues.  Thermal Truck and RV repair replaced hydraulic fluid,  found a seal leaking in the tank and checked hoses. I'm still overheating and having power steering problems so I need to get help.

Dan Stricker
2007 Contessa

[Rick Daniels]

My fan/steering pump went out while driving and after mega $$$$$$ in tow bills, the pump was removed to find that the spline was destroyed. My pump was driven off the CAT C-12 axillary drive. Managed to find a replacement pump but now need a monkey mechanic to put it back on because these old bones just cant do it myself anymore. Good luck.

[Chuck Jackson]

Another vote for Colton Truck Terminal. They are very knowledgeable on diesel pushers. They only work on chassis and generator but it’s not uncommon to see 4-8 high end coaches in there at any given time. I used to use them exclusively when I lived in SoCal.

[Larry Lee]

Hi Dan, sorry to hear you're having problems as well. Ironic we both have the same rig. I decided to order a new pump from the manufacturer in Italy ($1000). Once it arrives I'll make an appointment and take it in to Colton truck repair in Riverside CA. I ordered the pump over 2 months ago and supposedly it takes about 8-10 weeks to get here. I'm going to ask them to troubleshoot the problem first to see if we both came up with the same diagnosis before I produce the new pump for them to install. I'll update you hopefully soon with hopefully good news.

[Larry Lee]

FIXED! I ordered (3 months ago) a new pump from Cappassa and had it replaced by Colton Truck CA. Power steering pressure and fan speed has been restored!

[Jerry Carr]

Glad to hear about the repair, now go have some fun.