M48 tank – Cub Cadet M48 User Manual
Page 12

M48 Tank
8
5.14. Open the relief valve on the hydro pump that is
to be tested. This will relieve any residual 
hydraulic pressure. See Figure 5.14.
5.15. Confirm that the hydraulic pressure has been
relieved by rotating the brake drum / hub assem-
bly. If the it will not rotate, confirm that the brake 
is released and that the brake linkage is not 
bound.
5.16. If there is any possibility of fluid contamination,
drain and flush the system, and replace the filter 
before installing the new hydro pump.
5.17. Position a catch pan beneath the hydro pump to
be removed. Have four 1/2” JIC plugs and two 
1/2” JIC caps within reach.
5.18. Disconnect the feed line that runs from from the
front of the hydro pump to the filter manifold 
using a 7/8” wrench on the nut, and a 13/16” 
wrench to hold the fitting on the hydro pump. 
Plug the line, cap the fitting on the pump.
5.19. Disconnect the return line that runs from from
the outboard side of the hydro pump to the res-
ervoir using a 7/8” wrench on the nut, and an 11/
16”” wrench to hold the fitting on the hydro 
pump. Plug the line, cap the fitting on the pump. 
See Figure 5.14.
5.20. Disconnect the two lines that connect the hydro
motor to the back of the hydro pump using a pair 
of 7/8” wrenches. Plug the lines.  
See Figure 5.20.  
5.21. Remove the two O ring to JIC adaptors from the
back of the hydro pump. Replace them with the 
yellow shipping plugs from the replacement 
hydro pump.
5.22. Remove the 90 deg. elbow fitting that the return
line was connected to using an 11/16” wrench 
and a 3/4” wrench. Plug the port using a yellow 
shipping plug removed from the replacement 
pump. 
5.23. Remove the O ring to JIC adaptor that the feed
line was connected using a 13/16” wrench. Plug 
the port using a yellow shipping plug removed 
from the replacement pump.  See Figure 
5.23.
Figure 5.14
 
 
RETURN LINE
FEED LINE
OPEN
CLOSE
RELIEF VALVE
ELBOW
Figure 5.20
 HYDRO 
 MOTOR
HYDRO 
PUMP
PRESSURE LINES
BETWEEN PUMP 
AND MOTOR
ADAPTORS
Figure 5.23
