Toro Groundsmaster 4500-D Series Service Manual page 182

Procedure for Engine Cooling Fan Circuit Test
Hydraulic System: Testing
The engine cooling fan circuit test should be performed to make sure that the
engine cooling fan circuit has the correct system pressure and fan speed.
Prevent personal injury and/or damage to equipment. Read all
WARNINGS, CAUTIONS and Precautions for Hydraulic Testing at the
beginning of this section.
1. Make sure hydraulic oil is at normal operating temperature by operating
the machine for approximately ten (10) minutes. Make sure the hydraulic
reservoir is full.
2. Park machine on a level surface with the cutting decks lowered and off. Make
sure engine is off and the parking brake is applied.
g308527
1. Fan control manifold
2. Test fitting (port G1)
3. Raise and support hood to gain access to fan control manifold
Connect a 345 bar (5,000 PSI) gauge with hydraulic hose attached to test
fitting in port G1 on rear of manifold.
4. Start the engine and increase engine speed to high idle speed.
5. While monitoring the pressure gauge and using a phototac to identify the
cooling fan speed, disconnect the wire harness connector (white/violet and
black wires) from the proportional relief valve solenoid at fan control manifold
(port TS). Both fan speed and pressure should increase and stabilize after
the solenoid is disconnected.
PRESSURE GAUGE READING TO BE approximately 207 bar (3000 PSI).
PHOTOTAC (fan speed) READING TO BE approximately 2800 RPM.
6. Stop engine and record test results.
7. If pressure rises to approximately 207 bar (3000 PSI) but fan speed is low,
consider that the hydraulic fan motor is worn or damaged. If pressure and
fan speed are both low, consider that final gear pump section is worn or
damaged (see Gear Pump Flow (Using Tester with Pressure Gauge & Flow
Meter) (page 5–82)).
CAUTION
Figure 89
3. PRV solenoid
Page 5–80
3
1
(Figure 89).
Groundsmaster ® 4500-D/4700-D
19245SL Rev A