If they're not badly pitted, the joints should seal okay with a good cleaning like you did on one already, plus new o-rings. Be sure to keep any debris out of the ports and hoses. To ensure a nice tight seal, put a little Nylog Blue Label (available from this site's sponsor) on each o-ring prior to ...

You've been through a lot with this A/C already. In my humble opinion, the sound is normal for a variable displacement compressor. The compressor itself is new, the oil amount is correct, the pressures are good, it's charged with the specified amount and type of refrigerant, and vent temps are in th...

Easiest way is to drain the compressor, measure what comes out, and refill with same after repairs are completed. Otherwise, I'd figure one ounce each for the condenser and evaporator, one-half ounce for the accumulator/dryer, and maybe another one-half ounce for the lines, which of course is alread...

You also need a refrigerant scale to charge this accurately. Modern vehicles don't hold very much refrigerant and are very sensitive to the amount of charge. Just an ounce or two either way can and will cause problems. Charging with a manifold gauge set and a 30-pound cylinder is just a guessing gam...

The first one you received sounds iffy. If the second one seems questionable as well, this site's sponsor can provide a quality part that you won't have to worry about.

The high pressure sounds a little low, suggesting it's a bit low on charge. Drive it for a while and see whether it shows symptoms of evaporator icing. If not, leave it alone and enjoy the "cool."

Right off the bat it sounds to me like a clutch problem. The coil could be gradually failing or the clutch gap might be too wide.

What vehicle is this and what year?

When evacuating using a vacuum pump, you won't see much of anything coming out except for maybe a little oil. The refrigerant is long gone by that time. The idea is for the vacuum pump to lower the boiling point of any moisture in the system and to remove it by boiling it off. If after evacuating th...

The hose/manifold assembly is prone to leakage on your vehicle. Part of the assembly can rub-through on the timing cover and cause a loss of refrigerant...probably what happened here. We don't know the vehicle's history, but hopefully, that's the only major part that will need to be replaced. I also...

As you suggest, anything with dessicant in it should be well sealed so that it doesn't absorb moisture in storage. Every OEM receiver/drier I've ever installed has been tightly capped, and some are even vacuum sealed. I once purchased an aftermarket R/D that came with the sealing caps loose in the b...