sstterry said:
I have an older Freon based (R-12) HVAC unit that has developed a leak. Before having to replace the entire unit, I would like to try some leak sealer. My question is, if anyone knows, what is the best "drop-in" to use with an older R-12 system. I am assuming my system is empty now, but I would like to just put in the sealer and load it up with the drop-in and see if I can keep it going.
What kind of vehicle?
I guess more specifically, what kind of compressor?
The old york style compressors hold the oil in the bottom and work really well with r134a. USUALLY!
High side pressure is generally slightly higher, so any leak on the high side may get worse.
I would recommend changing the oil with a good PAG oil tho. For co.pressor life, it's a must! 134 wont carry the old mineral oil thru the system like 12 did.