# a/c guru's advice needed



## sirtokesalot (May 15, 2008)

i own a 1987 bmw 528e it originally had 2.81 pounds of r-12 freon. when i bought it i discovered someone did the r-134a conversion on it at some time. i recharged it at work using r-134a and charged it to 2.81 pounds. i did the recharge because it did not seem to be cool enuph. now ive read online i need to use less r-134a than was originally in there? did i recharge it correctly filling it to 2.81 pounds like it had factory? i work in a quick lube shop and no one there seems to know they just know how to push the buttons on the machine and to fill the system up by what the sticker on the car says was in there.


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## Midnight Tech (Dec 31, 2001)

When converting from R12 to R134, the general rule is to refill the system to 85% of its original capacity. More Freon is not better when it comes to R134.


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## sirtokesalot (May 15, 2008)

ok i have a buddy that has a/c gages. how much should i let out?how much is 85% of the 2.81 pounds that it used to take?


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## Midnight Tech (Dec 31, 2001)

I'd evacuate the system completely, note how much oil is removed by the recycling machine, then recharge to the proper level adding back any oil that was removed. That is the ONLY way to get the correct amount in the system.


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## Raylo (Feb 12, 2006)

Exactly MP. Gages are only good for a guestimate of what is happening in the system. Only way to get it correct is start from scratch and charge in the specified amount by weight.


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