Excessive System Pressure - Gilera Nexus 500 Workshop Manual

Nexus 500
- Visually check that the thermostat does not have
mechanical failures.
- Prepare a metal container with ~ 1 litre of water.
- Immerse the thermostat, and keep it in the middle
of the container.
- Immerse the multimeter thermometer probe
close to the thermostat.
- Warm up the container using the thermal 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 releases from the wire.
Opening starting temperature ~ 82° C
Specific tooling
020331Y Digital multimeter
020151Y Air heater
- Warm 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 venting procedure.
diagnosis

Excessive system pressure

1 - Check the expansion tank cap efficiency.
N.B.
THE CAP IS EQUIPPED WITH A PRESSURE RELIEF VALVE CALIBRATED AT 0.9 BAR.
Cooling system
COOL SYS - 9