Vauxhall CORSA Owner's Manual page 194

192 Vehicle care
Caution
Only use approved antifreeze.
Coolant level
Caution
Too low a coolant level can cause
engine damage.
Different coolant reservoirs are used
depending on engine variant.
If the cooling system is cold, the
coolant level should be above the
filling line mark.
Top-up if the level is low.
9 Warning
Allow the engine to cool before
opening the cap. Carefully open
the cap, relieving the pressure
slowly.
To top-up, use a 1:1 mixture of
released coolant concentrate mixed
with clean tap water. If no coolant
concentrate is available, use clean
tap water. Install the cap tightly. Have
the coolant concentration checked
and have the cause of the coolant
loss remedied by a workshop.