did you use the hoat coolant when you changed it ?
I just found my info on how that cooling system works .At the bottom it mentions the steering control valve i was talking about .
Good luck ,
The hydraulic radiator cooling fan used on the 5.7L gasoline and 3.0L diesel engines
replaces both the electric fan and the engine driven mechanical fan. This provides 5.7L
and 3.0L equipped vehicles with heavy trailer towing capability while at the same time
reducing unnecessary power drain on both the engine and the vehicles electrical system.
HYDRAULIC FAN STRATEGY
The hydraulic radiator cooling fan is controlled by the Front Control Module (FCM). A Pulse
With Modulated (PWM) signal from the FCM controls the fan speed. There are three inputs
to the FCM that determine what percentage of fan speed is required by the vehicle. These
· Engine Coolant Temperature
· Transmission Oil Temperature
· A/C System Pressure
By monitoring the desired operating parameters for these three inputs, the FCM can
determine if cooling airflow is required. If airflow is required, the FCM will slowly speed up
the fan until the parameter(s) are under control. Once the temperature or pressure is
reduced to within operating parameters the fan will speed up, slow down, or hold its speed
to maintain the temperature/pressure requirements.
NOTE: Even if the FCM is not requesting fan on operation, the fan blade will usually
spin between 100 and 500 RPM when the vehicle is at idle.
ACTIVATING THE HYDRAULIC FAN WITH THE SCAN TOOL (StarSCAN®)
Under the Engine Systems test heading, there is a subheading. “Hydraulic fan solenoid
test”, that has the selections, on/off. Activating the fan with the StarSCAN® will run the fan
at 100% duty cycle, which will help troubleshoot any system problems, and also help with
the hydraulic system deaeration procedure.
NOTE: Engine must be running to activate the fan with the StarSCAN®.
RADIATOR COOLING FAN HYDRAULIC FLUID PATH
Hydraulic fluid is pumped by the power steering pump though a high pressure delivery line
to the fan drive motor. As fluid is diverted through one or both G-rotor stages, rotational
motion is created as fluid moves from the high-pressure (inlet) side of the motor to the
lower-pressure (high pressure outlet) side. Fluid exiting the drive motor is divided into two
paths. In path one, fluid continues through a high pressure delivery line to the vehicle
steering gear to provide steering assist. This fluid then exits the steering gear under low
pressure and travels through a low pressure line to the power steering fluid cooler to be
cooled before being returned back to the power steering fluid reservoir. In path two, excess
fluid travels through a low pressure line back to the power steering pump fluid reservoir
NOTE: There is a steering flow control valve located in the fan drive motor. This
valve operates like the flow control valve found in the typical power steering
pump. A failed pump and/or fan drive can produce contamination that may
cause the steering flow control valve to stick.
Proud owner : 05 WK Ltd 5.7 HEMI
90 YJ Islander 4.2 Cam'd & Decked
94 ZJ Ltd 5.2
00 WJ 4.0 - new to me Aug/13