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A/C Retrofit
Posted: Thu Sep 12, 2013 5:38 pm
by TieMyShoe
Went to recharge my system today but unfortunate its still R12 as I figured it would be. I don't want to go the "redtek" route as I don't relish the thought of an explosive A/C system. I would rather do a proper R134A retrofit. My question is regarding the dryer, is there a north american cross over part? I can try drain the R12 oil from the OE dryer but there's still the small chance of killing the compressor should some R12 oil make its way though the R134a charged system.
Re: A/C Retrofit
Posted: Thu Sep 26, 2013 10:11 pm
by LeeHammy
LeeHammy wrote:
Ok so.... the only thing the drier does it filter out particles and moisture. The oil which will be mineral oil will be everywhere in the system (EVERYWHERE). The oil travels with the refrigerant in the system. This is why velocity is important with an A/C system so the oil moves with the refrigerant and can return to the compressor for lubrication. If the drier stopped all the oil (which it doesn't at all) then all the oil would leave the compressor get lodged up in the drier and plug the system up then the compressor would seize due to lack of lubrication because it all left and never came back.
All the drier needs to do is absorb moisture. Moisture, refrigerant and oil turn into acid (moisture is an A/C systems worst enemy). The compressor like any mechanical devise doesn't like operating in an acidic environment (more so with an electrically powered hermetic compressor but still not a good thing in automotive a/c).
The drier will just need to be for 134a and the correct size for flow. (Rated in tons.. 12000BTUs = 1Ton of cooling) The 134a should run alright with mineral oil. New 134a systems run with POE oil. The issue is if you add a POE system with old mineral oil parts or use a POE charged compressor on a mineral oil system . The two oils don't mix well and create a waxy build up that plugs up the metering device drier and causes other issues. You should be alright if you just use 134a with what is in there.. mineral oil (you wont need to add oil either). Its better then trying to add POE oil. One reason is you wont know how much to add and how much oil is already in the system. To much oil isn't good. You wont get rid of the old oil unless you flush it (not something joe mechanic at home can do ;) and mixing is worse then just running mineral with 134a. I hope this helps. Just remove all the R12 and evacuate the system if possible before you charge. If you cant make sure you purge the system with 134a to clear out any air (air has moisture) the drier will take care of the rest. Good luck.
Or just pay for an auto service place to flush the system with rx11 and charge it all new with 134a and POE. $$$$$