Automotive Air Conditioning Information Forum

I think we've established that.

How would you approach a tech. that is touted as a master auto. tech. but doesn't have a micron gauge? So far I haven't been able to locate a shop that uses an electronic vacuum gauge near where I live (Silicon Valley CA).
I've talked to the guy and he seems reasonable and willing to tackle the evacuation and charge instructions I got with my Porsche retrofit kit (hoses, evaporator, condensers, compressor, basically all new).
I'm thinking he might buy and use a micron gauge if I ask - he already agreed to change the oil on his vacuum pump and wasn't pissed that I asked re. that.
Maybe I'm worrying about too much and bringing this up will just confuse things, the analog gauges are good enough.
Thanks.

HC3 wrote:How would you approach a tech. that is touted as a master auto. tech. but doesn't have a micron gauge? So far I haven't been able to locate a shop that uses an electronic vacuum gauge near where I live (Silicon Valley CA).
I've talked to the guy and he seems reasonable and willing to tackle the evacuation and charge instructions I got with my Porsche retrofit kit (hoses, evaporator, condensers, compressor, basically all new).
I'm thinking he might buy and use a micron gauge if I ask - he already agreed to change the oil on his vacuum pump and wasn't pissed that I asked re. that.
Maybe I'm worrying about too much and bringing this up will just confuse things, the analog gauges are good enough.
Thanks.

No one needs a micron gauge for AC work, why you can't find a shop with one. The idea is that at ambient temperatures that moisture (and any residual flush solvent) will boil out of the system. With a traditional vacuum pump and gauge set, one can determine if decent vacuum is obtained, and let that pump 30-45 minutes. Whether a micron gauge or regular service valve gauge is used, VERY LITTLE air will remain in the system.

As Bill Shakespeare would've said: "Methinks you worry too much !!!"

By the time this thing gets repaired, its going to be winter.

No need to get mean! I'm planning on putting the compressor in today using DEC PAG 46. That's the last item.
Above we see bohica2xo recommend using a micron gauge and now it is recommended as not needed.
Maybe you two can hash it out while we watch/listen.

Sarcasm!

Micron gauge is great if you have one. But by no means is it needed!

OK - all is assembled. Multiple flushings of the new compressor and then filled with 5.75 fl. oz. of DEC PAG 45.
I spun the compressor in case we forget when doing the evac. and fill.
The shop loaned me a venturi pump and I bought a HF gauge set.
I'll try my hand at pulling a vacuum and see if I have any "obvious" leaks.
I can get an appointment during the first week in Aug. I'm sure you'all will be waiting for the results.
I don't want to wait until winter - I want the ambient as hot as possible.

Those venture pumps are a POS. If you're waiting a week or so, pull the best vacuum you can and place the system under positive pressure.

I can imagine the venturi pumps can't pull much of a vacuum.
Should I pressurize with compressed shop air? Should I get some nitrogen?
The system is "empty" at this point - only ambient air and oil in the compressor.
Thanks.

I can get a bottle of compressed Nitrogen pretty easy around here - not sure of the needed size but they are in the range of $35.
I assume when the shop hooks up to my system to evacuate the left over Nitrogen will not cause any issues.
I need to read up on purging with Nitrogen.