Traction Circuit Testing − Piston Pump/Hydrostat (P3) Flow And Relief Pressure Test - Toro Reelmaster 3100-D Service Manual

Traction Circuit Testing − Piston Pump/Hydrostat (P3) Flow and
Relief Pressure Test
g345006
Reelmaster ® 3100-D/3105-D
20252SL Rev A
Model 03171 (shown)
The hydrostat flow test is the third in a series of tests recommended to determine
traction circuit performance. The final traction circuit test is verifying the hydrostat
relief valve operation. This test compares fluid flow at No Load with fluid flow
Under Load. A drop in flow under load of more than 12% indicates an internal
leak or malfunctioning relief valve in the piston pump/hydrostat. A worn hydrostat
or malfunctioning relief valve is less efficient. Eventually, enough fluid by−pass
will cause the unit to stall under heavy load conditions. Continued operation can
generate excessive heat, cause damage to seals and other components in the
hydraulic system, and affect overall machine performance.
Special Equipment Required:
•
Pressure Gauge
•
Flow Meter with Pressure Gauge that has at least an 68 LPM (18 GPM)
capacity
•
Phototach (non−contact tachometer)
1. Park machine on a level surface with the cutting units lowered and the reel
engage/disengage switch in the disengage position. The engine should be
off and the parking brake engaged.
2. Read Precautions for Hydraulic Testing (page
3. Make sure that the traction pedal is adjusted to the neutral position.
Figure 44
Page 5–37
5–27).
Hydraulic System: Testing