Any a/c gurus out there-problem with mine?

[Botietruck]

Anyone familiar with the stock a/c system? I am having a few problems with mine and I am looking for some guidance.
The system has everything new. Condensor, evap. core, dryer, POA valve, expansion valve has been reconditioned & tested, new hoses, fan clutch, etc. After pulling a good vacuum and charging it with 134a -about 44oz., the ambient temp @ 85-88, I am getting 255 on the high side, 38 on the low side and vent temp is running 52 degrees. The engine is running at about 1500 rpm. The sight glass is milky. I was hoping to get about 45 degrees out of the vents. Here's my problem, after running the engine for about 30-45 min. I shut it off for about 30 min. to eat dinner. Came back and the compressor acted like it had pressure on the system, It would barely turn over by hand. I left it sitting for about an hour or so and came back and the compressor would turn free. Any thoughts?

[ChevLoRay]

If the sight glass is milky, seems to me that you would need to pull a vacuum on it and completely evacuate the system and recharge it. The milky appearance says it has some air in the system.

Beyond that bit of info, my part in this play is over. Since you did a switch to R-134a, without knowing any more about what got changed, like the drier, and the P.O.A. valve, it may be hard to offer additional assistance. I guess I'm happy I still got 5 cans of R-12....I was saving for my old age.

[truckdude239]

yup but 38 and 255 is a good reading sounds like you still have air int he system i recommend pulling a vacuum on the system for 45 mins to an hour and pull it down to -30psi after vac close your gages and watch them for 10-15 mins if they dont move your system is leak free

[stope4]

I jacked around with 134a for a couple years. My pressures were always good but my temperatures were terrible and even worse at idle. I had a leak so I decided to see if I could get this thing to work right. I did a little research which took me to the forum for ackits.com. Read a bunch and decided to give the below a try. I'm convince it works because my ac is downright cold. Don't know what temp it's blowing but it's just as good as any R12 ac i've ever owned and blows just as cold as my new vehicles.

Here's what you need to do. Adjust your POA to open at 26.5 psi. Factory for R12 is set at 29 psi. Look into both ends of the POA. One end will have a little adjustment screw. That is the screw that needs to be turned. I think counterclockwise lowers the opening pressure and clockwise raises the opening pressure. You'll have to use your ac manifold guages, buy a fitting that will allow you to blow air at 60 psi into the suction end of POA using an air compressor. The low guage will tell you the pressure. Once you get it adjusted, reinstall, evacuate and recharge. If you want to get it even better, buy one of the newer condensors called a parallel flow. I recommend Classic Auto Air because they have one that bolts right in but it's more expensive.