Weird air conditioning issue
 

I had two problems, and I believe one is fixed and the other has me scratching. Background: driving my 'burb, the A/C wasn't keeping up with the St Louis heat and humidity...well, mostly the heat. Refrigerant pressure was on the low end of good, and after a shot of 134 with some sealant, the rear blows ice cold. However, the front (dual-zone) does not.

I had suspected the door actuator because there have been a couple times when it had a kind of its own, and maxed the heat regardless of its setting, even though it was only once or twice. But that doesn't explain the passenger zone. While the rear blows ice cold, the front zones are mediocre at best, and inadequate at 90+ degrees (not to mention humidity over 70% at times). I pulled the dash to check the driver's side actuator, and it wants to turn continually, so I am going to replace it (I count it fixed because it appears to be an easy install). But even when I manually turn the A/C door by hand to each extreme, the heat works perfectly, but the cold is still pathetic.

So I'm stumped, an I'm hoping someone else can give me some advice.

Zac

I wonder if you clogged your expansion valve with the stop leak. I don't know why they sell that crap.

They sell it to gullible home mechanics like me, I guess. I'm guessing that this is probably beyond my own abilities because of the HVAC certifications needed. Or is there something that a regular home mechanic can do?

You can get a full gauge set and work on the A/C yourself, but it requires specialized skill and knowledge. If you don't have any idea what's going on it may be best left to the pros. It can veey easily ruin your day if you make a wrong move.

Which he already did. Now he will have to recover the system, disconnect lines from the compressor, flush the entire a/c system with a/c flush, replace the receiver drier and replace the expansion valve. Then refill the system.

Several hundred just in that project alone.