Sounds like a stuck expansion valve to me. Also, when charging the system, the interior fan should be on the low speed to have the lowest possible low side pressure to enable the charge to go in faster. Turning the interior fan on high increases the pressures on both sides and slows down the charging.

If the system has been open for any period of time, it contains moisture just like the atmosphere. Pulling a vacuum for an hour is typically sufficient. There are diminishing returns and the longer the time, the less air and moisture will come out. My experience shows that you can achieve a full vac...

I would recommend recovering the charge and again inspecting the system. As mentioned earlier, you are going to have to definitively determine if the compressor is seizing due to lack of lubrication or seizing due to high pressure. I would also recommend doing your system flush again and yes, replac...

I agree. Use two 12 oz cans and call it a day.

Regarding the 80% charge issue, if an old R12 system calls for 3.75lbs or R12, I will charge it to 3.0 lbs which is 80%. If the pressures and temperatures are not acceptable, I'll charge another .25 lbs or 4 oz. If no change, another 4 oz, and so on. If I see any degradation in performance along the...

The A6 is a great compressor, just not what is light and compact in today's vehicles. If you have an A6, stick with it.

Ultimately you are going to have to determine if high pressure is locking the pump or lack of lubrication. I believe you will find that it is high pressure.

I will agree with the above statement, but I would recommend CPSI hands down. Whatever you do, avoid Mastercraft as those units are junk.

Even if they pay you to take it, leave it on the shelf.

Sounds like you have a 70s era GM vehicle that has been converted to CCOT (cycling clutch orifice tube) system. They do work great but check two things. First, did you overcharge the system? Rule of thumb is to charge at about 80% of the R12 specs and go from there if needed. Second, most people on ...

I've had the same issues on the GM orifice tube systems of that era. You may be slightly overcharged and the orifice tube is the source of the groaning noise.

If the scan tool shows the evaporator temperature sensor to be 2 degrees F then there must be a sensor value. I doubt that it is an imputed value. On Mercedes, you typically see the evaporator temperature sensor inserted in the air duct close to the evaporator core but not in the evaporator core its...