what level
do i top it up to?

 

The 'atmospheric catchment tank' needs just a few inches of coolant level.
Leave room for expansion coolant as the system adds and subtracts coolant as required.

The reservoir cap and temperature/pressure does all the work.

 

Thank you.

 

It has an overflow so you don't need to worry much about overfilling it, your car will do a little wee if it needs to go.

 

Half filled is the usual recommendation.

Richard

 

I’ve only had to fill mine once, and repair the split hose that leads to the tank.

after that it’s been self regulating with no spills and no liquid variation more than an inch or two.