Toro Greensmaster 3120 Service Manual page 106

Steering/Lift Circuit Testing – Gear Pump (P3) Flow and Circuit
Relief Valve Test (continued)
Hydraulic System: Testing the Hydraulic System
Gear pump (P3) is designed to satisfy both steering cylinder and lift cylinder
needs simultaneously (at full speed throttle). The Gear Pump (P3) Flow Test
compares fluid flow at No Load with fluid flow Under Load. A drop in flow under
load of more than 15% indicates the gears and wear plates in the pump have
worn. Continued operation with a worn pump can generate excessive heat and
cause damage to the seals and other components in the hydraulic system.
The relief valve for the steering and lift circuit is integrated into the steering
control valve. If both steering and lift operations perform poorly, perform the gear
pump (P3) flow test and the circuit relief valve test.
If machine steering is sluggish or otherwise performs poorly, refer to
Circuit Testing – Steering Control Valve and Steering Cylinder Test (page
If cutting deck lift operation is unsatisfactory, check lift control cartridge valves
and/or lift cylinders. Additional information on these components is available in
the Service and Repair section of this chapter.
Special Equipment Required:
•
Flow Meter with Pressure Gauge that has at least a 16 LPM (5 GPM) capacity.
•
Phototach (non−contact tachometer).
1. Park machine on a level surface with the cutting units lowered. Make sure
engine is OFF and the parking brake is engaged.
2. Read and adhere to the information provided in
(page 4–35).
3. Measure and record the system charge pressure (without load). Refer to
Traction Circuit Testing – Charge Pressure Test (page 4–38)
information.
Page 4–60
Steering/Lift
4–67).
Testing the Hydraulic System
for additional
Greensmaster 3120
17230SL Rev C