09-21-2022, 05:49 PM
Two year delta... (update):
Today is Wednesday September 21, 2022. We have been parked at the Tiger Run Resort since Sunday afternoon. This is the first time we've been back in Colorado since 2020 when I originally discovered I had a cooling issue which has now grown to include the hydraulic system. A significant amount of time has been spent on this journey by several people and I believe we are slowly zeroing in on the problem or should I say problems.
When we conclude this journey I will provide more detail about paths taken. I can tell you this, I know more about this coach than I ever expected to in less than four years of ownership. If you've seen my post about the ZF Suspension I will tell you that is one of the paths we've been down.
Here's some info I gathered recently that might be interesting to some of you.
Specific to the 2004 Cat-13 Acert.
The engine ECM controls a 12v DC relay that controls the hydraulic fan solenoid in the hydraulic manifold block. When the coolant temperature rises above 217* F the ECM removes the 12v supply to the relay. The solenoid piston moves to FAN High or max speed position for the engine RPM and hydraulic pump flow and pressure. The ECM will apply the 12v to the relay when parameters return to normal. The engine ECM will also call for FAN High if other parameters are out of limits such as intake temperatures or loss of inputs from sensors.
In the normal fan operating mode, the fan speed is approximately half of the engine RPM. A few examples I recently recorded using a photo tachometer are:
Engine idle 600 rpm/Fan rpm 251
Engine 1000 rpm/Fan rpm 491
Engine rpm 1500/Fan rpm 758
When fan is in the High mode
Engine idle 600 rpm/Fan rpm 580
Engine 1000 rpm/Fan rpm 1012
Engine 1500 rpm/Fan rpm 1428
This is how the system was designed to run as explained by a engineer at Tulsa Oklahoma HydraQuip.
A quick phone call to the CAT RV Hotline 877-777-3126 provided the following coolant temperature information:
Max coolant temp is 225*. Damage may start when engine coolant temperatures exceed 225*. C13 heads can warp.
Normal upper operating range is 220*.
Ideal operating temperatures are 195* to 212*.
The coolant regulator (thermostat) starts to open at 190* and will be full open at 212*.
I can tell you that after I replaced the regulator, flushed the coolant system, replaced with CAT ELC coolant, thoroughly cleaned the radiator... the engine ran consistently at 195* most of the time. WHY??? because the fan was always on HIGH! Please check out your system to ensure proper operation. I've been told some owners want the fan on high always but that is their choice not a system that is not set up properly.
Here's a few picks of the manifold "block" and the solenoid "piston"
Today is Wednesday September 21, 2022. We have been parked at the Tiger Run Resort since Sunday afternoon. This is the first time we've been back in Colorado since 2020 when I originally discovered I had a cooling issue which has now grown to include the hydraulic system. A significant amount of time has been spent on this journey by several people and I believe we are slowly zeroing in on the problem or should I say problems.
When we conclude this journey I will provide more detail about paths taken. I can tell you this, I know more about this coach than I ever expected to in less than four years of ownership. If you've seen my post about the ZF Suspension I will tell you that is one of the paths we've been down.
Here's some info I gathered recently that might be interesting to some of you.
Specific to the 2004 Cat-13 Acert.
The engine ECM controls a 12v DC relay that controls the hydraulic fan solenoid in the hydraulic manifold block. When the coolant temperature rises above 217* F the ECM removes the 12v supply to the relay. The solenoid piston moves to FAN High or max speed position for the engine RPM and hydraulic pump flow and pressure. The ECM will apply the 12v to the relay when parameters return to normal. The engine ECM will also call for FAN High if other parameters are out of limits such as intake temperatures or loss of inputs from sensors.
In the normal fan operating mode, the fan speed is approximately half of the engine RPM. A few examples I recently recorded using a photo tachometer are:
Engine idle 600 rpm/Fan rpm 251
Engine 1000 rpm/Fan rpm 491
Engine rpm 1500/Fan rpm 758
When fan is in the High mode
Engine idle 600 rpm/Fan rpm 580
Engine 1000 rpm/Fan rpm 1012
Engine 1500 rpm/Fan rpm 1428
This is how the system was designed to run as explained by a engineer at Tulsa Oklahoma HydraQuip.
A quick phone call to the CAT RV Hotline 877-777-3126 provided the following coolant temperature information:
Max coolant temp is 225*. Damage may start when engine coolant temperatures exceed 225*. C13 heads can warp.
Normal upper operating range is 220*.
Ideal operating temperatures are 195* to 212*.
The coolant regulator (thermostat) starts to open at 190* and will be full open at 212*.
I can tell you that after I replaced the regulator, flushed the coolant system, replaced with CAT ELC coolant, thoroughly cleaned the radiator... the engine ran consistently at 195* most of the time. WHY??? because the fan was always on HIGH! Please check out your system to ensure proper operation. I've been told some owners want the fan on high always but that is their choice not a system that is not set up properly.
Here's a few picks of the manifold "block" and the solenoid "piston"
Kristi & Jeff King
Bentonville, Arkansas
#744 2005 45’ Newell Coach
ZF Suspension/Active Steering Tag Axle
CAT-13 ACERT KCB Engine 525HP 1642 ftlbs Torque Cat Compound Turbocharger 43.5 psi
Allison HD4000MH Transmission with PTO drive.