When coolant expands from heat, the expansion reservoir takes up excess coolant.
"LOW" and "FULL" level marks facilitate coolant level inspection and top-up; see 2.10.1.
See 1.3.1 for more details on coolant.
1. Cylinder thermistor; 2. Expansion reservoir connection tubing; 3. Plain radiator cap (no breather); 4. Radiator to thermal expansion valve tube; 5. Centrifugal pump (intake); 6. Expansion reservoir; 7. 70° thermostat; 8. Breather union; 9. Radiator breather; 10. Radiator; 11. Cylinder head cover