A/C Capacity?

What's the charge capacity of oil and refrigerant (R12 or R134) for the factory system on a GS?

 

http://www.v8buick.com/showthread.php?87884-freon-capacity-for-70-GS-455-AC-system

 

Thanks for the link. What about oil capacity?

 

What should the pressures be?

 

I usually add the whole 8 oz bottle of oil into the compressor while I turn it by hand. Any extra ends-up in the filter/dryer. The pressures depend on the outside temperature. At 90 degrees you should be 275 psi on the high side and that's with a full load, windows down, fan on high. With the windows up fan on low you should see 175 to 200.

Are you running R12 or 134? If you change to 134 you need a POA valve and expansion valve calibrated for 134. Make as much air as possible go through the condenser by sealing your fan shroud to the radiator and the radiator to the core support and the core support to the condenser. I use pipe insulation for 1/2" pipe and fill the voids so ALL THE AIR goes through the condenser.

 

r12

 

According to the 1971 service manual for 43-44000 series (Skylark and derivatives) the charge volume is 3-3/4 lbs.