Ac leaks on 97 Ranger

[harlyrider66]

I pin pointed the leak I think to the valve stem on low side service port.After running ac for a while, when I shut off truck there is a hiss that lasts for a few seconds and it sounds like it's coming from cannister where I serviced ac. Is this normal sound when shutting of truck with ac running???

 

[BrooklynBay]

Welcome to this forum! Put some bubble solution on that spot to see if it starts to blow bubbles.