PIAGGIO 500 cc, Руководство по обслуживанию

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11 - 8
Cooling
System seal control
- Check adequate seal of the circuit when it is under pressure and heated;
- For a more complete control wait until the system has cooled because small leaks, invisible due to evaporation
phenomena, may occur;
- The water pump has a drainage hole for any leaks resulting from mechanical seal of the cooling system or of the
oil seal from the spindle seal;
- On discovery of coolant or oil leaks, proceed with overhaul of the pump (see Chapter 5-FLYWHEEL COVER).
N.B. : During repairs on the cooling system, do not use grease or oils. Failure to respect this regulation causes
permanent deformation of the gasket seals.
Diagnostics guide
Eccessive system pressure
Check condition of the expansion tank plug.
N.B. : The plug has an overpressure valve calibrated to 0.9 bar.
There is also the valve which must allow entry of air during the cooling phase.
Check gasket seal of the head (see Chapter 7-
THERMAL UNIT AND TIMING SYSTEM)
Replace the plug.
NO YES
Coolant consumption
Check external seals of the system as described previously.
Check gasket seal of the head (see Chapter 7-
THERMAL UNIT AND TIMING SYSTEM)
Proceed to repair of the damaged seals.
NO YES
On discovering water leaking into
the engine oil, check
the head cooling circuit pad.
Presence of oil in the coolant.
Check of the head gasket seal (see Chapter 7-THERMAL UNIT AND TIMING SYSTEM)