QuestionMY 1990 JEEP CHEROKEE LAREDO'S AC NEEDS RECHARGEING. THERE ARE KITS AVAILABLE TO ADD FREON. MY QUESTION IS CAN YOU PUT R-134 IN WITH R-12? SOME SAY YES AND SOME SAY NO. THEY ALSO SAY THAT THE ENTIRE SYSTEM WILL NEED TO BE VACUMED OUT AND THEN THE FREON CAN BE ADDED. I NEED TO KNOW WHAT I CAN DO. I AM DISABLED AND CANNOT AFFORD A BIG COST. I NEED TO KNOW WHAT I CAN DO TO FIX THE PROBLEM AT MINIMUM COST. THANK YOU BOB
AnswerYou ABSOLUTELY CANNOT mix the R-12 with the R-134 freon as they are incompatable.
1. remove ALL the R-12 freon.
2. Add EXACTLY the correct amount of R-134a refrigerant
per instructions on the R-134 kit.
3. Evacuate all the atmospheric air from the system using
a vacuum pump for a minimum of 30 minutes.
4. Make SURE you have no leaks by watching the vacuum pump
suction side so that it holds the vacuum for 15 minutes
after you turn off the vacuum pump without loosing any
vaccuum.
5. Add ONLY 75% of the R-134 refrigerant to the system.
Look somewhere under the hood or on the firewall and find the sticker that say's how much R-12 the system holds.
EXAMPLE: If the sticker say's it holds 4.25 lbs of R-12
You would only add 3.18 lbs of R-134. 4.25 x 75%
= 3.18.
Follow the kit directives EXACTLY. And do NOT forget to mark down somewhere under the hood or next to the A/C sticker: CONVERTED TO R-134 FREON.
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