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OEM capacity w/new condenser r12-134

Vetteman61 on Thu August 28, 2014 8:30 PM User is offline

I am almost finished with the 134 conversion on my '71 Pontiac Grand Safari station wagon. So far I have:
-New Pro6Ten compresser
-Rebuilt POA and calibrated for 134a
-Aftermarket 28.5" parallel flow condenser
-New evaporator core
-New dryer of course
-All new lines being made

I've read a lot of threads and from what I understand, because I have changed the old tube and fin compressor to a parallel flow, I can recharge the system back to the OEM capacity for refrigerant instead of the typical 90% rule for 134a.

The Pro6ten compressor came with Pag 46 oil and said it may require more depending on the ratio required by my system. If more is needed will I simply buy a can of 134a with pag46 oil in it and add the correct amount when charging the system? (I'm not currently sure what the correct ratio is. I'll need to do more research to find it for a '71 Pontiac Grand Safari).

Also, I want to coat the O-rings with oil as recommended on this site. If the oil I buy is in pressurized cans how can I add it to the o-rings? Would I have to buy an entire can in a liquid, non-pressurized just to coat the O-rings?


Edited: Thu August 28, 2014 at 8:39 PM by Vetteman61

mk378 on Thu August 28, 2014 9:40 PM User is offline

Do not put PAG oil on o-rings. Use mineral oil or Nylog for that. PAG oil exposed to the outside world absorbs water and foments corrosion. It should be used in the closed system as a compressor lubricant only.

If you need more PAG, buy it as liquid in a tightly sealed container that is not under pressure and measure and pour it into a component or line just before making up the connections and closing up the system.

Edited: Thu August 28, 2014 at 9:42 PM by mk378

Vetteman61 on Thu August 28, 2014 10:45 PM User is offline

OK, thank you for the reply, that is very good information to have.

I spent quite a while and did some math and determined that my system needs 4 1/8 pounds of 134a and since my compressor came with 7.44 oz of PAG 46 then I need to add 3.51 more ozs to it. How do I go about adding the extra 3.51 oz of compressor oil?


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