Master cylinder caps

[Mog-nuts]

Hi, A simple question i'm sure someone out there will be able to answer.

In what situation would you use a non vented filler cap on the master
cylinder.

Thanks in anticipation

[charlie_morris_minor]

where you have a remote reservoir fitted as the remote is mounted higher up than your master cylinder it will empty out through the vent.

[Mog-nuts]

Thanks for that Charlie,common sense really. I thought there'd be a simple answer !