a/c charging with 134a

[leford4]

Does anybody know the correct amount of 134a I need to charge my system for a 85 Supra? I had a rebuilt compressor and new dryer installed and the shop said their book said it takes between 22 to 28 ounces. Thats what they put in it, but it still has bubbles in the sightglass. It gets cold but I think it should get colder, and I don't think the bubbles are supposed to be there. They are afraid to add more.

[zuprax85]

book says (1.4-1.7lb) thats for the r-12, but you need to put less when u charge the system with r-134, i put 1.2lb in my system and works great, what are the gauge readings??? for how long did you vacuum the system? whats the temperature comig out of the vents???

[leford4]

I had somebody else do this, since I'm not very good on a/c. He said he put a vacuum on the system to make sure it held and put 2 cans of 134a. The bubbles in the sight glass are normal, according to him. He said he checked with a Toyota shop and they said thats normal. Is that true?

[zuprax85]

how many oz were those cans? where did you get the drier with the sight glass?

[leford4]

16oz., Advance Auto. Temp is 48 degrees at the vent.

[zuprax85]

TSRM says bubbles are not normal.

http://www.cygnusx1.net/Supra/Librar....aspx?S=AC&P=5

[Pwner_Guy]

If there are bubbles it means that somethings not right. Sight glass should be clear. It you change your drier when you charged it?

[leford4]

yes, new dryer. 48 degrees not cold enough? how cold should it be?

[zuprax85]

48 is pretty good, 40 should b the desire temperature.

[leford4]

OK, he vaccumed it out again and charged it again, still bubbles!!! Any idea whats going on? New dryer and remanufactured compressor. This guy wonks on a/c's all the time and he's stumped.