@flintknapper You sir are a saint. Thank you for taking the time to type all that out, especially on a Saturday. I had already done a little work previous to reading your post, but for the most part I followed it to the letter.
The good news is that I have AC in my car! Its a weird feeling riding around in the summer with the windows up! The less-than-good-news is that its still not as cold as I think it should be based on my research. Currently in the peak of the heat today (about 87F with 48% humidity) the lowest it registered was about 49F at the center vent. It would cycle between about 49 and 54 consistently. Now, that was still pretty chilly, but based on what I've read its not as cold as it should be, and I want it to function as intended. Please correct me if Im wrong on this, and these temps look correct.
If I am correct, and it could be colder, then I think the problem is the following.
1. I didn't vacuum long enough. Because this was a learning process there were several instances where I pulled a vacuum, messed something up and pulled again. It always pulled to -30, but I think that what I really needed to do was pull to -30 and leave it for like 5 hours to get rid of all of the moisture and air in the system.
2. As
@mellowdave has said, I probably could have been better about purging the lines of all air. I attempted this, but may not have been as careful as I could.
@flintknapper I would love to know what you think about this, and especially what the normal vent temp should be. I can always buy some more freon and try again tomorrow. Third time's a charm! (hopefully)
Meanwhile, thanks to everyone who has chimed in. It goes without saying that this community is invaluable.
P.s.
@mudgudgeon Do it! The repairs themselves only took about a day and were straight forward. If I had to do it all over again I could probably do it in less time than that, and Im no mechanic.
Well.....you're getting there, and I applaud you for sticking with it.
To address a few of your questions, yes...I believe there is still some additional cooling to be had. But we must be careful NOT to assign a specific target number that applies universally. There are just too many variables (weather conditions, vehicle condition, etc). Generally speaking, if you can achieve vent temps 35°-40° F. degrees below ambient you're doing pretty darn good.
Vent temps are going to fluctuate with conditions of course, but the 'spread' will normally be fairly consistent. If you were sitting in traffic, idling on hot blacktop with 95° F. ambient, I'd be tickled to death to see 50°-55° vent temps (fan on high w/recirculate). Now...lets change the environment: Nightfall, 80° F. ambient, highway speed 70 mph. If I didn't see 40°-43° F. vent temps, I would be looking at the engine cooling system. We expect the actual 'vent temperature' to change, but I also want to see that 'spread' (difference between ambient and vent temp) maintained (roughly 35-40°, sometimes a bit more).
But this is isn't always practical, one vehicle to the next, so I throw those numbers out there as a general guideline only. You might have a perfectly charged, leak free system, but if your engines cooling system is not 'tip-top', then your A/C will suffer for it. A perfectly charged and functioning system A/C system only insures that a good heat exchange is 'possible'. IF there isn't sufficient air moving through the condenser, performance will be poor (or at least not as good as it could be). If your fan clutch is weak, it not only isn't pulling all the air it could through the condenser, but also not your radiator. Once the engine/trans/radiator and engine compartment get good and heat soaked, it will make it tough for your A/C system to work at its best.
Solar gain (sunshine coming in through windows) will have an effect. There are lots things working with (or against) your A/C system depending on circumstance. So....chasing down those last few degrees of cooling can be challenging, but usually worth it.
Back to YOUR vehicle: Yes too much oil in the system will have an effect on its ability to transfer heat, but a small amount (an ounce or so over) isn't going to be that concerning. Moisture and air are to be avoided. Likewise flushing agent. Many folks suppose they removed all the flushing agent because they see none while blowing compressed air through the lines/components. And depending upon which agent you used (some evaporate quickly) you may of may not have it all out.
When blowing out the lines it is important to block the escape route of line/component with your finger and let pressure build up. Using a blowgun with a rubber tip apply air at one end while blocking the other, then quickly remove your finger. This will cause a very forceful release of the air pressure and will carry any liquid and debris with it.
Once you no longer see a 'mist' discharging, you should be good to go. But make sure to drain your air compressor frequently as you go, water from the compressed air will build up in it. We don't want that in the lines or components.
Pulling a vacuum: It is easy to think that if your compound gauge is showing 28-30 inHg, that you have satisfied the need to have a vacuum on the system. And for that purpose alone, you have. BUT...the other purpose for pumping the system down (and the MOST IMPORTANT) is to remove moisture. This can take time. I won't even consider pumping down a system for less than an hour, usually two and more if the system has been flushed or I suspect some moisture might still remain (turn your manifold valves off with the pump still running when you are ready to quit). If you use a traditional pump, be sure to use FRESH pump oil each time you pull a vacuum.
Purge your lines: ALWAYS purge your lines each time you connect to a can of refrigerant and before opening any valves. If you don't you are introducing air and moisture right back into the system you just worked so hard to remove it from. Small amounts....yes, but we don't need any. Do it right!
So...with a new or completely evacuated system, we need:
1. A CLEAN system (all lines and components)
2. A leak free system. For obvious reasons.
3. Properly working components (TXV, Condenser, Evaporator, Compressor, Clutch, Pressure switches)
4. Proper charge of oil and refrigerant.
If you do this....you will have a properly operating, long lasting A/C system. Don't take short-cuts, its not worth it.
Putting in an all new system or charging a completely evacuated system is the easiest of all scenarios. We are dealing with known quantities and components.
Diagnosing or charging a faulty/partially charged unit is where things get dicey and you need to know your stuff.
Folks, when doing A/C work, go slow, be thorough, do it ONCE (the right way) and you will be rewarded, I promise.
