I'm converting to r-134a and don't know how much to put in. They say 85% of what the system holds of r-12 but I don't know whow much that is. Does any know? My car is here at the shop now and that's all I got left to do. Thanks, Jason

 

JAS,

I'm not sure if they are exactly the same, but my '86 TA takes 3.75 puond of R-12.

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Later,
Vader
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"Let the bodies hit the floor!"
Adobe Acrobat Reader

 

Holy ****, mine holds 2.25 of R12. The most I've ever seen a third-gen hold was around 2.75. Maybe you have a high-capacity system. It should be under the hood somewhere.

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82camaro

 

The manual for my 1989 says that the system takes 2.25 pounds of R-12. I would think this should be pretty close to the same as an 87.
Later-
Mike


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Smokin 1989 GTA- Bone stock except for exhaust. (no catalytic-stainless pipe into Flowmaster 2 chamber.

 

48oz of R-12
40oz of R-134A(31.5oz refrigerant, 8.5 oz oil)

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89 Transam GTA, 350TPI, auto, 3.27 rear, dual cats, gray.
Magnaflow cat-back,
K&N open element,
Best E.T. 14.63@95mph

 

K - that's three pounds, so where's my extra 12 ounces going? We're halfway between the oft-reported 2¼ pounds and 3.75 pounds. Maybe I've got a monster accumulator or something. I have the same R4 compressor as almost every GM car since the late '70s, so whassup? All I know is I can nearly make ice cubes, but the T-Tops suck up so much sun that 65° in the car doesn't feel all that cool.

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Later,
Vader
------------------
"Let the bodies hit the floor!"
Adobe Acrobat Reader

 

Your system holds 2.25 lbs of R-12. When I do thirdgen conversions, I put in 2lbs even. The general rule of thumb is 80%, but it is used as a STARTING POINT, you can add more to acheive the desired pressures, wich is about 2lbs. Its tried and tested, go with it.

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Thanks for all the help. I got 2 pounds in it and it seems to work great.

 

Amazing to keep this site around. 20 years later, this thread helped me! Thanks TGO!