R410a
 

By the way , you all probably already know this . But , on the off chance some one does not , I will throw it in .

I read R410a is a blend / mix of 2 types / kinds of refrigerants . Instructions say to always charge with liquid ( tank up side down ) .

On my leak , I was fortunate enough to catch it while it still had a little pressure in the system . I valved off both service valves , so I did not have to worry about air / moisture entering the system .

Of course , it did when I re-flared the small line . When I vacuumed the system down , I was really only pulling a vacuum on the lines and the indoor fan coil unit .

I have read of the 3rd world method of just purging the lines with a little R410a gas . With the equipment , copper , insulation , tooling , etc. , plus the labor that went into the install . I was not about to take a chance on that method !

Besides , I had already made one dumb mistake ! :-( And , I had long ago acquired the tooling to evacuate the system .

By the way , my unit has only a 1/4" service fitting , on the large service valve . But not on the small service valve . I have since learned not to call them high pressure and low pressure valves / lines . I read that , in heat pump mode , the high side becomes the low side , and vice versa ?

I have read there MAY be a service fitting on the small line , inside the condenser cabinet ?

I am surprised , I figured the mini split would use the service fittings found on automotive R134a systems ? But mine does not .

God bless
Wyr

Nylog Blue also works on R22 and R12.

Good to know , Thank you . :-)

I did not know if it would contaminate the mineral oil ?

I have read that Nylog is polymerized refrigeration oil ? In the case of Blue , I guessed it was POE ester oil ?

Before I start up my central A/C condenser , next spring / summer , I need to swap out the Schrader valves . ( I have the tool to do this w/o discharging the R22 . )

The system has a very slow leak , that I have not found anywhere else in the system & Schrader valves are a likely suspect ?

I had planed to coat the new Schrader valves with mineral oil , but from what you have told me , Nylog Blue would be OK , too ?

God bless
Wyr

Service valve leaks are very common, especially if the installer didn't remove the valve cores while brazing the connections.

Huh???
 

Brazing connections? Why would you ever braze a flare connection? Please help, I don't get it.

Most central units in the US use brazed connections.