Hydraulic drive system: diagnosis, Cub cadet commercial z-wing – Cub Cadet Z-Wing User Manual
Page 54
Cub Cadet Commercial Z-Wing
50
23.8. The fluid will also drain out of the lines leading to
the pumps. See Figure 23.8.
23.9. The heavier hoses carry pressurized fluid
between the pumps and the wheel motors.
See Figure 23.9.
•
The right side pump and wheel motor are
plumbed “A” to “B” and “B” to “A”.
•
The left side pump and wheel motor are
plumbed “A” to “A” and “B” to “B”.
•
This is necessary because two identical pumps
are driven in the same direction, but mounted in
a mirror-image relationship to one another. The
mounting reverses the direction of the control
inputs to one pump.
23.10.The wheel motors are manufactured by White
Hydraulics. There is no financial nor managerial
relationship between White Hydraulics and
White Outdoor Power. They are a separate
company, and Cub Cadet Commercial is simply
a customer. See Figure 23.10.
•
White wheel motors feature a unique roller stator
design: The rollers reduce friction directly and
recover an oil film faster than a standard fixed
surface.
•
For more information, visit:
//WWW.Whitehydraulics.com
•
The model used here is of the CE Series.
24.
HYDRAULIC DRIVE SYSTEM: DIAGNOSIS
24.1. The method used for testing the pumps is called
a “Flow Droop” test.
•
The flow rate is tested at a pressure of 300 PSI,
and again at 1,100 PSI. The two flow rates are
compared to determine if the pump is damaged.
•
If the pump is determined good, and there are no
external factors hurting the performance of the
drive system, then the motor can be determined
to be at fault through the process of elimination.
24.2. Before condemning (or even testing) a pump or
motor, a variety of external factors should be
checked. These include:
•
Dragging brake
•
Wrong fluid or filter
•
Leak or fluid starvation
•
Partially open relief valve
•
Belt / tensioner issues
Figure 23.8
From filter
To other pump
NOTE: cooling
fan removed
for visibility
To tank (reservoir)
“S”
“T”
“B”
“A”
To Wheel
motor
Relief
valve
Figure 23.9
“B”
“A”
Figure 23.10