Evacuating an all new AC system question.

[565bbchevy]

Wait- they sold you a complete system and didn't specify the amount of oil? Yikes! What if you weren't curious and just hooked it all up, oblivious. Contact them immediately. Last time I used my vacuum pump it was low on oil. NO ONE had any in stock. I fianally located a tiny 8oz bottle at an Auto Zone many miles away that got me by. I have since bought a gallon of Black Gold so I don't get caught with my pants down again.

No one sold me a complete system, for my Regal the parts are all new factory replacement parts and are mostly Four Seasons brand and the condenser I believe is a Spectre I got the best price from different vendors Amazon, Summit, Rock Auto and bought everything over the past couple years.
And since the Monte is a completely custom set up there is no kit , I started with a polished Sanden 508 from Vintage Air just to see if I could make it fit somewhere and I am finishing making brackets to mount it on the passenger side of BBC above the alternator and I have my pulley set up done with a serpentine belt for the AC and the rest of my V-belts will remain.
I just ordered the trunk mount unit also from Vintage Air and I think I am going to go with Old Air Products for the remote condenser to have more mounting options.
Once the main components are in place I will start making lines and have already ordered a beadlock crimper for the fittings, as you can see it is pieced together.

 

[565bbchevy]

I do not know much about AC systems so I am doing as much research and asking questions to learn as much as I can before I get to the point of charging both systems. I still have a lot of work to do on both cars before then and the Regal I have to install the SBC before I do this.

 

[Bonnewagon]

Oh, OK, I thought it was a kit or something. Yeah the Regal is easy to get specs but the Monte I think you need some professional help. I don't know enough to make any sort of recommendation. At the very least you could look up and see what car uses that same Sanden and see what the amount of oil is.

 

[565bbchevy]

I sent an email to Vintage Air Friday night just to see if they can give me a recommendation for the oil based on the components I bought from them.
Worst case scenario there is a place that does custom AC installs near my work so once I finish the install if I don't have enough info I can take it there for recharging.

 

[fleming442]

I'll throw this out there: when I first did the system in my Bonne, it was all new or reman parts, except for the lineset, for a 2002 Firebird. Upon installation, I poured 6oz of oil into the low side line from the drier to the compressor as I thought it should flow down to the compressor inlet. That was in complete disregard of the instructions that said to install said oil into the compressor via the fill plug under the bright pink sticker. I had nothing but problems- all self inflicted. Each time the system was opened (and installed), it was pulled down to 30in of vacuum. The compressor eventually failed.
This last go-round, I filled the compressor as instructed, and spun it over by hand to make sure it didn't hydrolock. I also installed a new drier and orifice tube. I did not add oil to any other components. It has been going well for about a week and a half <knocks on wood>. Now, I don't know Jack Schitt about A/C systems, but results are results.
I thought the drier (accumulator?) had dessicant to pull the moisture out, not the oil. I realize that the PAG I am using may be different hygroscopically than whatever goes in an R12 system. Are the 2 that much different?
I'm just adding to the conversation- not trying to hijack, but would like to learn something.

 

[Bonnewagon]

I thought the drier (accumulator?) had desiccant to pull the moisture out, not the oil.

Yes, it does. But it takes the moisture out of the entire system and stores it. Also once a system has been opened for any length of time the dessicant will be so saturated no amount of vacuuming will dry it. That is why it is always recomended to replace it. The oil is hygroscopic but that is not it's primary purpose. It is to lubricate the compressor which is the only moving part. But any moisture it picks up will circulate through the system with the oil. Any moisture that ends up at the orifice tube or expansion valve will freeze and block the flow. That is why some systems cycle regularly to allow it to defrost and to prevent that. The engineers have calculated how much oil the system needs to lubricate the compressor while allowing for puddling in the accumulator, evaporator, and condenser. That amount will be listed in the AC specs of the factory manual. When replacing an entire system it is advised to add specific amounts of oil to the components so upon startup there will be enough oil where it is needed. Putting it all into the compressor and not hand turning it gets you what you described- and possibly hydrostatic lock. 565bbchevy has an engineering problem because his system is custom and the components are so far from each other. Actually his system is not that different from a ductless home AC system. You know, where the condensor is outdoors and the hard lines go into the home where the evaporator is located. That is why I said professional advice is indicated.

 

[565bbchevy]

So Vintage Air emailed me back for my question:
So I have your new Sanden 508 compressor and I will be installing your trunk mount 685000-VUY and a remote condenser and drier and then making lines for everything.
So the compressor comes with oil so do I have to drain it and reinstall it after the system is evacuated? What is the procedure for this.

And the response:
Do not drain the oil from the Vintage Air provided Sanden compressor. The compressor has a full oil charge of 7.2oz of SP-20. Any oil that may have been removed during evacuation, must be measured and returned to the system. You can use PAG100 as a substitute.

 

[79 USA 1]

Just did the system in my 88 Monte Carlo SS, so this may work on your Regal. New AC Delco R4 compressor which came filled with assembly lube.(Pink warning tag on compressor) Had to drain compressor and add 3oz of new oil for type of refrigerant used then allow compresssor to sit clutch side down for 3+ minutes to allow oil to lubricate the front seal . Rotated the compressor by hand after the 3 minute wait and once again after mounting it in the car. New condenser took 1oz and accumulator took 5oz per the 1987 Chevy manual.

 

[Bonnewagon]

Save that email for future reference in case something goes south. They didn't advise adding any oil to the components? I guess they are expecting the freon to carry it along and deposit it where it will. Be sure to do as 79USA1 said and spin the compressor by hand to make sure it isn't going to hydrostaticly lock up. As for your question, no, you will not be evacuating anything. On a regular system that contains freon you are supposaed to evacuate the old freon into a reclamation machine. It is illegal to evacuate any kind of refrigerant into the atmosphere. If any oil gets out the machine will separate it. Sealers will damage the machine so if a shop suspects that they may refuse to evacuate your system. You normally install all the components adding the specified amount of oil to each. Then you make all the connections with new "O" rings and seals lubricating them with some oil. Once everything is in place and double checked, then you begin vacuuming the system down. First you try to get to 30" vacuum for 5 minutes, and then you shut the valve and watch the gauge. You need for the system to hold vacuum for at least 5 minutes. If it won't then you have a leak. I have seen systems hold vacuum for half an hour and still leak later on. Water boils at 29" vacuum so they specify 30" to be sure. So any water vaporises and gets carried out by the vacuum pump. They recommend doing a deep vacuum (30") for at least an hour. I sometimes go and have lunch or do something else for several hours and just let the pump run. Especially on a system that I did not replace the accumulator. After vacuuming then you are ready to add the freon. Did they advise how much to add? On most cars there is a spec, usually a sticker under the hood, but in the manual for sure. R134a requires a specific amount- no more- no less- for optimum performance. The old R12 way of adding more until it gets as cold as it can won't work with R134a. I use a digital scales to get the exact amount. I place my 30lb can of freon on the scales and slowly add while watching the digital readout. Then I check the low and high side gauges to see what they are doing. At this point you will know if the system is functioning properly or if there are any problems. If you can't get the specific amount of freon to add, then you will at least need the low and high side pressures @ what ambient temperatures recommended. Then you can slowly add freon while watching the gauges and stop when you are getting the right results. It only takes several ounces of freon to close the low pressure cut-off switch so don't be fooled- you must watch the gauges.

 

[565bbchevy]

After vacuuming then you are ready to add the freon. Did they advise how much to add?

I don't have the evaporator yet but the instructions say add 2 lbs of R134a.