Toro GroundsmasterR 4300-D Service Manual page 79

3. Read Precautions For Hydraulic Testing in this sec-
tion.
CAUTION
Before opening hydraulic system, operate all hy-
draulic controls to relieve system pressure and
avoid injury from pressurized hydraulic oil. See
Relieving Hydraulic System Pressure in the Gen-
eral Information section of this chapter.
4. Raise and support operator seat to allow access to
hydraulic pump.
5. Identify suspected faulty pump section to be tested
(Fig. 48). Thoroughly clean junction of gear pump fitting
and hydraulic outlet hose. Disconnect hose from pump
fitting:
Pump section (P1) for rear cutting decks
Pump section (P2) for front cutting decks
IMPORTANT: Make sure that the oil flow indicator
arrow on the flow gauge is showing that the oil will
flow from the gear pump, through the tester and into
the hose.
6. Install tester with pressure gauges and flow meter in
series between disconnected hose and gear pump fit-
ting. Make sure the flow control valve on tester is ful-
ly open.
7. After installing tester, start engine and run at idle
speed. Check for any hydraulic leakage from test con-
nections and correct before proceeding with test.
8. Make sure the parking brake is engaged. Move
throttle to full speed (3200 RPM). DO NOT engage the
cutting decks. 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.
9. While watching pressure gauges, slowly close the
tester flow control valve until 1500 PSI (103 bar) is ob-
tained on gauge.
FLOW TESTER READING TO BE: A pump in good
condition should have a flow of approximately 13.6
GPM (51.2 LPM) at 1500 PSI (103 bar).
10.Open the tester flow control valve and stop the en-
gine. Record test results.
Groundsmaster 4300--D
11. If flow is less than 12.1 GPM (45.8 LPM) or a pres-
sure of 1500 PSI (103 bar) cannot be obtained, consider
that a pump problem exists. Check for restriction in
pump intake line. If intake is not restricted, remove gear
pump and repair or replace pump as necessary (see
Gear Pump and Gear Pump Service in the Service and
Repairs section of this chapter).
12.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 from
machine and connect hydraulic hose to gear pump fit-
ting.
13.Lower and secure operator seat.
1
3
1. Gear pump assembly
2. Pump P1 outlet hose
Page 4 - - 47
2
Figure 48
3. Pump P2 outlet hose
Hydraulic System