Which fitting do I need to adapt to hose guage manifold?

[Johnds]

Hello, I bought a can of refrigerant from autozone.(second picture below). It has the female R134a low side connector at the end of its hose that attaches to the male R134a port on the car. Instead of hooking it directly to the car, I want to attach it to the hose of my refrigeration gauge manifold first so that I have plenty of hose to work like a gentleman. I know I need to buy an extra R134a low side port to be able to accomplish this, but the problem is, I dont know what size male NPT x male flare fitting I need to come out of the other end.

1) What size male NPT x male flare do I need to fit in the fitting in the first picture below that would allow me to attach my hose guages? (First picture below)

2) I also am going to purchase fittings that allow me to hook my guage hoses to the car's R134a high side and low side ports(last picture below). With that said, am I able to pull a vacuum on the system through the high side and low side ports? I dont know if there is something inside the ports themselves that would not let it operate in reverse? Like the shrader pin maybe? Would it stop me from pulling a vacuum?

[JohnHere]

Your pictures didn't appear, but I think I know what you mean.

Why not make it simple? Return the can with the attached hose and purchase a can of R-134a (pure refrigerant only...no sealer or other additives), a valve for the self-sealing can, and connect the valve directly to the yellow hose from your manifold gauge set.

Bear in mind that you can't gauge the amount of refrigerant in a system by pressures alone.

[JohnHere]

The correct adapters fitted to the red and blue hoses, connected to the system, will depress the Schrader valves when you rotate the thumb wheels fully clockwise.

[Tim]

Your pictures didn't appear, but I think I know what you mean.

Edited. Just a huge image of one of the hose and can products.