bryson711

does anybody know how many ounces our trucks take from a completly empty system? i had to evacuate mine when i done my conversion and i have found some r12 locally to buy, i just need to know how much to get

sooty

you have a sight glass on the receiver dryer, charge until foam/bubbles goes to liquid/clearbeen years since i did mine, seemed to be 28 oz's

jimbo486

IIRC, it's something like 2.2lbs.?

bryson711

Thanks guys, I have found a few cans of r 12 for sell locally. I figured I better pick it up

Sent from my DROID2 using Tapatalk

j_martin

I refill these old R12 systems with a mixture of isobutane and propane. One 8 oz. can of ISO-PRO mountain stove fuel, and 1 14 oz. Coleman propane fuel bottle will charge the average automotive AC system. It works very well, and is compatible with the seals and oils involved.

There are commercial versions of this available. It's refrigerant C12

If you charge a flat or evacuated system, just dump in the Isobutane first, then the propane (higher pressure). If you pre-mix it in a bigger refrigerant container, you have to withdraw it as a liquid, or the propane will evaporate off first.

It's considerably lighter than freon, so it takes less weight.

Coleman seem to be the best driest available, although I've used Worthington in a pinch.

They've done some safety studies and analysis in Europe. The feared rupture AND fire in a collision are statistically almost impossible. You're much more likely, by many orders of magnitude, to be injured by scrap metal on the road rupturing your plastic gasoline tank and incinerating you.

jimbo486

I'm sorry, my recollection of 2.2lbs is for a retrofitted system charged with R-134a. R12 runs at a lower pressure than R-134a. Since that is the case, if charging with R12, it will take more than 2.2lbs. Unfortunately, I don't know just how much. Somebody else here knows for a fact and hopefully will chime in shortly.

carrnutt

44oz R-12

Don't forget to add oil too.

j_martin

Amount doesn't have anything to do with pressure, but with molecular weight. R134 is lighter than R12.

bryson711

thank you! this was the answer i was lookin for! is there a certain type of oil i need to get?