Cub Cadet 5000 Series - Manual (Page 13)

Domestic Series 5000 Hydraulics
9
5.8. The charge pressure should read at least 30 PSI
(2.07 Bars) @ 1,200 RPM. See Figure 5.8.
5.9. As the RPM is increased to the 3,000 RPM, the
pressure may increase somewhat. If pressure
goes down as engine speed increases, turn-off
the engine and determine the cause.
5.10. After confirming that the supply to the pump is
good, low pressure or a complete lack of pres-
sure at this port indicates:
• The auxiliary pump that is not working.
• Pressure from the auxiliary pump is not reaching
the charge port on the hydrostatic drive. The
steering unit may not be transferring pressure as
designed, or the return manifold check valve
may be failing to maintain 30 PSI (2.07 Bars).
• Pressure is being lost within the hydrostatic
drive, possibly because of a malfunctioning sys-
tem relief valve.
Figure 5.8
200 PSI gauge High pressure gauge
5.11. If the charge pressure is good, but drive has
been lost in one direction only, the correspond-
ing charge check valve may not be working.
• There is a charge check valve located in each
circuit: one for forward, one for reverse.
• These check valves enable the charge pump to
provide charge oil to the side of the circuit that
has the lowest pressure, while sealing-off the
side that has higher pressure.
• The one on the left side maintains pressure in
the forward circuit, the one on the right side
maintains pressure in the reverse circuit.
5.12. The charge check valves can be removed using
a 5/8” wrench. See Figure 5.12.
NOTE: The one on the right side (reverse) is
easy to reach. The one on the left side (forward)
can not be removed in the tractor. It may be
removed for inspection on the bench.
Figure 5.12
Charge check
valve cap
O-ring seal