Service And Repairs 4 - Toro Groundsmaster 4000-D Service Manual

The PTO circuit relief pressure test should be performed
to make sure that the PTO circuit relief pressures are
correct.
Procedure for PTO Relief Pressure Test
CAUTION
Prevent personal injury and/or damage to equip-
ment. Read all WARNINGS, CAUTIONS and Pre-
cautions for Hydraulic Testing at the beginning
of this section.
1. Park machine on a level surface with the cutting
decks lowered and off. Make sure hydraulic oil is at nor-
mal operating temperature, engine is off and the parking
brake is applied.
2. Locate PTO (deck) manifold to be tested (Fig. 38).
Disconnect hydraulic hose at PTO manifold port (M1).
NOTE: An alternative to using manifold port (M1) would
be to disconnect the inlet hydraulic hose to the deck mo-
tor.
3. Install tester (flow and pressure) in series with the
disconnected hose and PTO manifold port (M1) (or mo-
tor inlet if hose was disconnected at deck motor). Make
sure the flow control valve on tester is fully open.
CAUTION
Cutting deck blades will rotate when cutting
decks are lowered with PTO switch in ON posi-
tion. Keep away from cutting decks during test to
prevent personal injury from rotating blades. Do
not stand in front of the machine.
4. Start engine and increase engine speed to high idle
speed. Release the parking brake.
5. Watch pressure gauge carefully while slowly closing
the tester flow control valve to fully closed.
6. As the PTO relief valve lifts, system pressure should
be approximately:
2900 to 3100 PSI (200 to 213 bar) for the center and
left decks
1900 to 2100 PSI (131 to 144 bar) for the right deck
Groundsmaster 4000--D/4010--D
7. Fully open tester flow control valve and disengage
cutting decks. Shut off engine and record test results.
8. If relief pressure is incorrect, remove PRV valve on
mow manifold and clean or replace valve (see PTO
Manifold Service in the Service and Repairs section of
this chapter). Also, if pressure is still low after PRV valve
service, check for restriction in pump intake line. The
front gear pump section (center cutting deck circuit) and/
or the second gear pump section (side cutting deck cir-
cuits) could also be suspected of wear, damage or
inefficiency (see Gear Pump Flow Test in this section).
9. When relief pressure testing is complete, disconnect
tester from PTO manifold and hydraulic hose. Recon-
nect hydraulic hose that was disconnected for test pro-
cedure.
RIGHT
FRONT
1
1. Center PTO manifold
2. LH PTO manifold
LEFT PTO MANIFOLD SHOWN
1
1. PTO manifold
Page 4 - - 57
3
2
Figure 38
3. RH PTO manifold
2
Figure 39
2. PRV valve
Hydraulic System