Toro GroundsmasterR 4300-D Service Manual page 85

4. Raise and support operator seat to allow access to
hydraulic pump.
5. Thoroughly clean both ends of the hydraulic hose
that connects gear pump (P4) outlet (Fig. 54) and lift
control manifold P4 port. Remove hydraulic hose. Ac-
cess to hydraulic hose at lift control manifold can be ob-
tained from below the machine.
IMPORTANT: Make sure that the oil flow indicator
arrow on the flow meter is showing that the oil will
flow from pump (P4), through the tester and to the
lift control manifold.
6. Install tester with pressure gauges and flow meter in
place of the removed hydraulic hose. Connect tester in-
let hose to the pump fitting. Connect the tester outlet
hose to the lift control manifold fitting. Make sure the
flow control valve on tester is fully open.
7. Make sure that the traction pedal is in neutral and the
parking brake is engaged.
8. Start engine and run at idle speed. Check for any hy-
draulic leakage from test connections and correct be-
fore proceeding with test.
9. Move throttle to full speed (3200 RPM). Use a
tachometer to verify that engine speed is correct.
IMPORTANT: The gear pump is a positive displace-
ment type. If pump flow is completely restricted or
stopped, damage to the pump, tester or other com-
ponents could occur.
10.While carefully watching pressure gauges, slowly
close the tester flow control valve until 1000 PSI (70 bar)
is obtained on gauge.
FLOW TESTER READING TO BE: A pump in good
condition should have a flow of approximately 3.2
GPM (11.9 LPM) at 1000 PSI (70 bar).
11. Open the tester flow control valve, stop engine and
record test results.
12.If flow is less than 2.8 GPM (10.6 LPM) or a pressure
of 1000 PSI (70 bar) cannot be obtained, consider that
a pump problem exists. Check for restriction in pump in-
take line. If intake is not restricted, remove gear pump
and repair or replace pump as necessary (see Gear
Pump in the Service and Repairs section of this chap-
ter).
NOTE: If the flow from gear pump (P4) is low, the opera-
tion of all lift cylinders will be affected.
Groundsmaster 4300--D
13.After testing is completed, make sure that engine is
stopped, then relieve hydraulic system pressure (see
Relieving Hydraulic System Pressure in the General In-
formation section of this chapter). Remove tester and
connect removed hydraulic hose to gear pump (P4) out-
let and lift control manifold P port.
14.Lower and secure operator seat.
1
2
1. Gear pump (P4)
Page 4 - - 53
Figure 54
2. Hydraulic hose
Hydraulic System