Cub Cadet 5000 Series - Manual (Page 17)

Domestic Series 5000 Hydraulics
13
6.10. Set the parking brake, place the gear selector in
neutral, open the flow valve on the gauge set all
the way, and confirm that no unsafe conditions
will be created by starting the tractor engine.
6.11. Start the engine, allow the engine and hydraulic
system to warm-up. See Figure 6.11.
6.12. Performance:
• The SKP1/4.3 S auxiliary pump does not contain
a relief valve. It is capable of producing roughly
3,600 PSI (250 bars) at engine speeds beyond
1,200 RPM.
• This is far in excess of the needs of the rest of
the system, which is designed to operate at
1,500 PSI (103 Bars).
• For our purposes, it is not necessary to test the
pump to its full capacity, only to establish that it
produces enough flow and pressure to operate
the hydrostatic steering and hydraulic lift cylin-
der.
• The auxiliary pump was observed to move about
4.6 GPM (15 LPM) at an engine speed of 3,000
RPM, with no load applied.
• Flow will vary with engine speed, but pressure
tests can be done at lower engine speeds:
1,200-1,500 RPM.
• Set the throttle to maintain an engine speed in
this range, and note the reading on the flow
meter.
Figure 6.11
To P port on
steering unit
From auxiliary
pump
Valve
open
5 GPM
6.13. Close the flow valve until the pressure gauge
reads 1,500 PSI (103 Bar). Note the flow read-
ing. See Figure 6.13.
6.14. As soon as the flow reading is noted, open the
the flow valve completely, relieving pressure
from the system. Turn -off the engine.
6.15. The flow readings noted at zero pressure and
1,500 PSI (103 Bars) should not vary signifi-
cantly. Flow is more related to engine RPM than
to pressure.
Figure 6.13
1,500 PSI
5 GPM
Valve
partially
closed