Thermostat; Fan - Toro 500 EFI Service Manual

INSTALLING
1. Place the radiator into position making sure the grom-
mets are correctly installed; then secure to the mounts
with the two shoulder bolts and nuts. Tighten securely.
2. Connect the upper and lower coolant hoses to the
radiator and secure with the appropriate hose clamps;
then connect the cooling fan wire connector to the
main harness.
3. Open the high-point bleed screw on the thermostat
housing to allow trapped air to escape. Tighten
securely after filling.
4. Pour the recommended coolant into the radiator and
secure the radiator cap.
5. Start the engine and warm up to operating tempera-
ture; then verify the coolant level is at the bottom of
the stand pipe in the radiator neck. Add coolant as
necessary.

Thermostat

REMOVING
1. Drain approximately one quart of coolant from the
cooling system.
2. Remove the two cap screws securing the thermostat
housing to the cylinder head. Account for a thermo-
stat with seal.
INSPECTING
1. Inspect the thermostat for corrosion, wear, or spring
damage.
2. Using the following procedure, inspect the thermostat
for proper operation.
A. Suspend the thermostat in a container filled with
water.
B. Heat the water and monitor the temperature with a
thermometer.
C. The thermostat should start to open at 71.0-86.0° C
(160-187° F).
D. If the thermostat does not open, it must be replaced.
3. Inspect all coolant hoses, connections, and clamps for
deterioration, cracks, and wear.
PR184A

NOTE: All coolant hoses and clamps should be
replaced every four years or 4000 miles.
INSTALLING
1. Place the thermostat with seal into the thermostat
housing; then secure the thermostat housing to the
cylinder head with the two cap screws.
When installing the thermostat, make sure the bleed
holes are straight up and down or air will remain
trapped causing engine damage due to overheating.
PR183A
2. Fill the cooling system with the recommended
amount of antifreeze. Check for leakage.
REMOVING
1. Remove the radiator.
2. Remove the fan assembly from the radiator.
INSTALLING
1. Position the fan assembly on the radiator; then secure
with existing hardware.
CAUTION

Fan

PR281A
123