Service Manual

HYDRAULIC SYSTEM
5-39Toro Z Master G3 3000/5000/6000 Series Service Manual
5
5. Completely open the restriction valve on the ow
tester.
6. Start the engine.
7. Slowly bring engine up to maximum operating
speed.
8. Move the vehicle’s motion control lever on the side
that is being tested all the way into the forward
position. Have someone hold the motion control
lever to prevent false readings.
9. Continue to operate without any load to allow the
system oil temperature to rise.
Note: Raising the temperature of the oil will make a
difference in your readings. To complete the
test accurately, the oil temperature should fall
between 110º and 140º F (43.3º and 60º C).
10. Tighten the restriction valve until the difference
between the pressure gauge readings is 300 psi (21
bar). Record the ow reading from the bidirectional
ow meter.
11. Tighten the restriction valve unit the difference
between the pressure gauge readings is 1000 psi
(69 bar) and record the ow reading again.
12. The maximum allowable ow rate change is shown
below. If the difference exceeds this level, the pump
is unacceptable.
13. When testing is complete, re-install the motor port
plugs. Torque to 35 to 50 ft-lbs. (47.4 to 67.8 Nm).
Series
Displacement
cc/rev (nominal)
Max. Allowable
Flow Rate
Change* (gpm)
UHT 12 to 16 1.0
*Max. Allowable Flow Rate Change is equal to the ow
rate at 300 psi minus the ow rate at 1000 psi.
EXAMPLE:
First Reading 300 psi (21 bar) 5 gpm (19 I/min)
Second Reading 1000 psi (69 bar) -3 gpm (11 I/min)
Difference 2 gpm (8 I/min)
By subtracting the second reading from the rst, a
defective pump can be identied. In the example above,
2 gpm indicates a defective pump.