What is this? What does it do?

[Supra_UK_]

Hi,

Can anyone let me know what does the little grey valve/tap/screw top do? It's near the coolant area on a shiny silver pipe about half inch.
I kind of "accidentally" (idiotically) moved it slightly while doing an engine bay wipe down just going through motions, now my anxiety is like "did I mess something up"?
Is it supposed to be tightened up all the way?

Sponsored

 

[razorlab]

AC system. That’s where you charge/bleed the system

 

[Supra_UK_]

AC system. That’s where you charge/bleed the system

Thanks @razorlab. If I turned the knob a quarter turn anticlock wise do you think that might cause an issue? Anyway to know how it should be normally? (As I don't know the effect)
Thanks!

 

[razorlab]

Thanks @razorlab. If I turned the knob a quarter turn anticlock wise do you think that might cause an issue? Anyway to know how it should be normally? (As I don't know the effect)
Thanks!

It’s just a cap for the valve. No issue.

Sponsored