AC Recharge - low pressure valve issue

[MikeB63]

Has anyone ever had an issue with "activating" the low pressure valve on their AC system? I connect the hose with the gauge to low pressure connection, but can't add fluid. The gauge on the hose does not register any pressure when I connect it and if I try to add fluid, it just seems to pressurize the hose. It was very difficult to connect the hose, but when I finally did, I couldn't charge the system. Any suggestions would be appreciated.

[Digger]

The same valve set on millions of cars, not just Saab's. If valves never went bad, they wouldn't make special tools to replace bad valves without dumping Freon into the air.

[MikeB63]

Thanks Digger. I never knew they made these tools.