Freon question

[GOLD513]

I have a 1985 930 turbo. I need to recharge the system with r12, but don't know the correct amount to fill. I don't want to put to much in system.

Thanks in advance for any help you can give me.

[88911coupe]

Not sure if this helps but the owners manual for my '88 3.2 doubles for the manual for the '88 Turbo and it says 47.6 oz. of R12 and makes no distinction between the n/a aspirated model and the turbo.
HTH,

[GOLD513]

Thanks for the reply. My turbo is european and don't know if the american and european a/c system capacities are the same.

[ruf-porsche]

Originally Posted by GOLD513

I have a 1985 930 turbo. I need to recharge the system with r12, but don't know the correct amount to fill. I don't want to put to much in system.

Thanks in advance for any help you can give me.

If you really want to do it right, you will evacuate all the existing freon from the system, pull a vacuum and use an electronic scale to measure the amount of freon going into the system, or just hook up a set of manifold gauge and see what type of pressure you have for the low side and the high and what the ambient temp is.

[kuehl]

What ruf is saying is that for a particular refrigerant type there is a P&T (pressures and temperatures chart) chart. When you are charging the system you are doing two things,
first you are referencing the amount of refrigerant you are putting in, say the manual suggests
47 ounces nominal, you note the outside ambient (temperature) and look up the suggested high side pressure ; you are watching the amount of refrigerant to see if you are near the suggested amount because if you have a system or procedural problem the measured amount will alert you, and as well the P&T chart will alert you, if you hit both targets you are typically good to go.