Review on 🔌 High/Low Side Quick Couplers R134a Recharge Kit - Lu-Hawk Automotive with Self Sealing and Single-Use Can Tap Valves, Plus Valve Core Removal Tool by Amador Buckenmeyer

I'd appreciate any feedback on how link valves work. That's the deal. I have an old set of gauges and would like to upgrade with these fittings. I would like to flush the hoses with refrigerant R-134 before installing them in the vehicle. I received the connectors, I decided to practice a little before connecting. I found my hose seals were bad, ordered new ones, but was surprised I couldn't open any of the ports and bleed the R-134. I have both divider valves and link valves fully open, no gas. I got gas in the connecting hose fittings. I removed the connectors and tried cleaning them, nothing. I expected them to work like a water valve. what am i missing (I rated them high based on other reviews)