Toro Groundsmaster 4100-D Service Manual page 105

Procedure for Engine Cooling Fan Circuit Test
1. Make sure hydraulic oil is at normal operating tem-
perature by operating the machine under load for
approximately ten (10) minutes. Make sure the hydrau-
lic tank is full.
2. Park machine on a level surface with the cutting deck
lowered and off. Make sure engine is off and the parking
brake is applied. Raise and support hood.
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.
3. Raise seat to gain access to fan drive manifold (Fig.
48). Connect a 5,000 PSI (345 bar) pressure gauge with
hydraulic hose attached to test port on top of manifold
(Fig. 49).
4. After installing pressure gauge, start engine and run
at idle speed. Check for hydraulic leakage at gauge
location and correct before proceeding with test.
5. Move throttle so engine is running at high idle speed
(2870 RPM).
6. While monitoring the pressure gauge and using a
phototac to identify the cooling fan speed, disconnect
the wire harness connector (white/green and black
wires) from the PRV solenoid on fan drive manifold. Both
fan speed and pressure should increase and stabilize
after the solenoid is disconnected.
PRESSURE GAUGE READING TO BE approxi-
mately 3000 PSI (207 bar).
PHOTOTAC READING TO BE: fan speed should be
at least 2800 RPM.
7. Stop engine and record test results.
8. If pressure rises to approximately 3000 PSI (207
bar) but fan speed is low, consider that the fan motor is
worn or damaged. If pressure and fan speed are both
low, consider that the gear pump is worn or damaged
(see Engine Cooling Fan Circuit Gear Pump Flow Test).
NOTE: If pressure and fan speed are both low and gear
pump flow proves to be correct, suspect that seals in fan
drive manifold are leaking or faulty (see Fan Drive Man-
ifold Service in the Service and Repairs section of this
chapter).
9. When testing is complete, remove pressure gauge
and reconnect wire harness to PRV solenoid.
Groundsmaster 4100--D/4110--D
1. Fan drive manifold
2
1
1. Fan drive manifold
2. PRV solenoid
Page 4 - - 67
2
1
Figure 48
2. Test port G1
3
RIGHT
FRONT
Figure 49
3. Test port G1
Hydraulic System