Gilera 633721 Workshop Manual page 335

Nexus 500 euro 3
- Visually check that the thermostat exhibits no
mechanical faults.
- Prepare a metal container with approx. 1 litre of
water.
- Immerse the thermostat, keeping it in the centre
of the container.
- Immerse the multimeter temperature probe close
to the thermostat.
- Warm up the container using the heat gun.
- Heat the water and periodically pull the thermostat out until its opening becomes visible.
- Insert a thin copper wire between the seat and the thermostat closing plate.
- Keep the wire into position until locking up is perceived.
- Let water and thermostat cool down.
- Progressively heat the water keeping the thermostat immersed by the wire.
- Check the opening temperature when the thermostat is released from the wire.
Opening starts temperature approx. 82° C
Specific tooling
020331Y Digital multimeter
020151Y Air heater
- Heat up until the thermostat is completely open:
N.B.
HEATING SHOULD BE GRADUAL.
N.B.
AVOID CONTACT BETWEEN THERMOSTAT AND CONTAINER FOR A CORRECT TEST PER-
FORMANCE.
- If incorrect values are detected, replace the ther-
mostat.
- Repeat the filling and bleeding procedure.
diagnosis
Excessive system pressure
1 - Check the expansion tank cap efficiency.
Cooling system
COOL SYS - 335