Aston Martin DB 9 2010 Manual page 218

Engine Coolant Level Check
Warning: Do not remove the filler cap until the coolant
system has cooled. Scalding can be caused by escaping steam or
coolant.
Use a cloth or glove to protect hands and protect face and arms
adequately.
1. Remove the pressure cap to check the coolant
level. The correct coolant level is to the top of
the reservoir tank. Top up with the correct anti-
freeze mix (Refer to 'Fluids', page 12.12), if
required.
11.12
2. Make sure the filler cap is secure after topping up.
Do not over tighten.
If required to remove the pressure cap before the engine is cold, use
gloves or a protective cloth and slowly loosen the pressure cap.
Allow residual pressure to slowly drop. Continue to turn the pressure
cap until it is released.
Power Steering Fluid Level
Make sure power steering fluid does not contact the paint
work during topping up. Serious paint work damage can result. If
a spillage does occur, immediately flush any power steering fluid
from the paint work with clean fresh water, then wipe with a
clean damp cloth.
Always check the reservoir level when the engine is
cold and with the front road wheels in the straight
ahead position.
Wipe the reservoir cap clean before removing to
prevent an ingress of contaminants.
1. Remove the reservoir cap and wipe the dipstick clean with a lint
free cloth. Replace and remove again. The fluid level should
read between the Min. and Max. marks.
2. If required, top-up fluid level. Do not overfill.