Automotive Air Conditioning Information Forum

Checking things and I had to add a little, and I forgot to purge my charge hose. I always purge but forgot one time.
Things seem to be ok, and I may be just too OCD about things, but how bad of a screw up is this?

Also I think I read once about how to NOT lose refrigerant in the hoses when just checking things.
It went like this and I may have gotten it off this forum.

To prevent refrigerant loss, this is what you need to do:
1.) Shut off car (safety)
2.) block the center port on manifold with a cap.
3.) CLOSE the valve on car end of high side. Disconnect from car.
4.) Star the car and A/C.
5.) Open both high and low valve on the manifold. This will flush the refrigerant trapped in high side hose back into the system and since the low side is the coldest part of the entire loop, liquid refrigerant will not become trapped in service hoses.
6.) Turn off the car, quickly shut off the car side valve and remove the low side connection. You will lose approximately 120cm^3 of gaseous refrigerant at 50psi or so from the system which amounts to 0.1 to 0.2oz by weight, which is negligible.

Question is....would I be introducing air into the system do this?
The hoses have some air in the lines when you connect them, that does not get to escape, so I feel like this procedure would be pulling that air inside the system.

Should I just not do that and let some waste just be waste?

digeratimvp wrote:Checking things and I had to add a little, and I forgot to purge my charge hose. I always purge but forgot one time.
Things seem to be ok, and I may be just too OCD about things, but how bad of a screw up is this?

I say if cooling performance is acceptable, then don't worry about it, leave it be.

The best type of quick connect fittings are the ones that have the knob valves built right into the connector to the system.
If using that type, connect up your gauge set hoses, but keep the knobs closed. Connect your charging can or jug to your yellow service hose.
Open the jug or can. Open both the red and blue handwheels on the manifold.
Then crack open the knurled knobs that attach to the quick connects. Wait for the gas to hiss thru, then tighten (snug up) the knurled fittings.
Now, the entire manifold set and all hoses are free of air and you can proceed with opening the knobs on the quick connects.

The engine can be off for the steps above.
It is easier to disconnect the quick connects if the AC is off. This reduces the pressure in the lines. Close the handwheels on the manifold.
Disconnect the high side (red) quick coupler first, but otherwise leave the red and blue hose connections alone. Leave the low side quick connector in place and do not mess with the low side hose.
Shut off the jug or can but don't remove. There will be high pressure liquid in the red hose remaining. Now open the blue handwheel. Now slowly crack the red handwheel. This will allow the high pressure liquid in the high side to bleed back into the low side. You will now only have low pressure vapor in all the lines, and all connections can be removed.
Unless you do mobile AC all the time, most of us do not leave a charge in the hoses. At least I don't.

The directions you posted seem unnecessarily complicated and because the units are not USA units I doubt you got them from this site, FWIW.