I am replacing the A/C compressor and I am supposed to add the new oil to it in the same quantity as was in the one that came out. So, the bad one had ZERO oil in it. How much do I add of the 8 oz. bottle? Converting to 134A if it matters. Thank you.
A/C Compressor Oil - Quantity to add? (1 Viewer)
- Thread starter jjvbva
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- #2
Answering my own question. Google to the rescue! Compressor model is Denso 10P15C and oil capacity is 8 oz. Same size as the bottle. Perfect.
If you are converting to 134 don't forget you need to flush all the old oil out of lines. The different oils don't mix
Any body know the best way to flush out the old oil?
Flush bottles at autozone about 40.00.Id change our dryer and o-rings. Mike
Does the compressor require the oil to be topped up? This is the first I have heard of that.
If you change a compressor you must add oil to it and turn shaft about 15-20 times, then seal it back up. Mike
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- #8
Oh boy. I did not flush the lines and also did not add freon. I did replace the rec/dryer and o-rings. I have all hoses connected. My plan was to take it to the shop and have someone do it properly since I don't want to screw it up. Is this still OK or do I need to do something before I take it to the shop? I was thinking they "evacuate" the system in the process. But if that screws up the new oil that is added, then maybe I should do this fushing action. Appreciate the insight.
well, the correct answer almost requires a certificate in refrigeration - but: you need the correct oil for the refrigerant type. the refined mineral oil used with R12 is not useful with R134. the oil actually is moved by the refrigerant and moves thru the entire system. a full 8-oz oil fill leaves 2-oz in the compressor, 2 in the condensor, 2 in the evaporator and 2 in the accumulator/drier. SO - you ONLY replace the oil for the component being replaced. and in this case, you need a different oil that is miscible with R134 - such as a poly-alpha. IF you want the ac to work - you MUST pull a complete vacuum and use a gauge set to install the refrigerant. pure refrigerant in a complete vacuum gives you cooling power. you should be comfortably cold with 134a in your older machine - mine works great.
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- #10
Thanks but still a bit confused. I did use R134a compatible oil when I filled the pump with the 8 oz. Since I did not flush the lines at the same time, am I at a point where I need to remove everything and flush the lines with this $40 kit OR can I just leave as is and let the A/C guy charge me up?
leave it all alone now; have your local shop pull a complete vacuum, and then charge with refrigerant.
why might you have to or not have to flush now? good question. if the leak if FAST the oil leaves with the refrigerant - if the leak is slow most of the oil remains in the system. since you say above that the compressor had no oil in it when removed it might have been a fast leak (there should be a wet/oily area around the leak where the oil residue collects dirt). also, the old oil in your system has sealed your rubber hoses so you don't need to replace them when switching to 134a. BUT if you get new hoses, they would need to be r134a resistant - older hose used for r12 will allow the new refrigerant to migrate thru the hose (not good). extra/old mineral oil (used with r12) that remains in your system will have little effect if you add no additional mineral oil - it does not circulate with the refrigerant in the system because it does not dissolve and move with the r134a. the 134a compatible oils/lubricants are very effected by moisture/water vapor in the system. when you "open" the system to replace components or seals you allow atmosphere that contains water vapor into the system, and while this would seem a very small amount - it has a great impact in the system, which is why you replace the desiccant in the accumulator to grab any water in the system - the oil/refrigerant/desiccant must all "match" for things to be balanced and work right.
If you just charged your system now (without an evacuation) and ran the AC, you would get vent temps no better than about 57F based upon where you are geographically located, but once you pull a complete vacuum (30-minutes minimum) your vent temps can be between 38-41F.
For people in locations where it is routinely over 98F (SW USA) you may want to keep your r12 system as the "curve" is better for mobile refrigeration. There are other refrigerants that can/are being used in the southwest, including purified hydrocarbons (like butane) with good effect - however, these are flammable. Any refrigerant other than pure r12 or r134a will not be serviceable by cooling shops - they will not want to contaminate their cylinders with an "unknown" refrigerant.
there is so much more to say...
why might you have to or not have to flush now? good question. if the leak if FAST the oil leaves with the refrigerant - if the leak is slow most of the oil remains in the system. since you say above that the compressor had no oil in it when removed it might have been a fast leak (there should be a wet/oily area around the leak where the oil residue collects dirt). also, the old oil in your system has sealed your rubber hoses so you don't need to replace them when switching to 134a. BUT if you get new hoses, they would need to be r134a resistant - older hose used for r12 will allow the new refrigerant to migrate thru the hose (not good). extra/old mineral oil (used with r12) that remains in your system will have little effect if you add no additional mineral oil - it does not circulate with the refrigerant in the system because it does not dissolve and move with the r134a. the 134a compatible oils/lubricants are very effected by moisture/water vapor in the system. when you "open" the system to replace components or seals you allow atmosphere that contains water vapor into the system, and while this would seem a very small amount - it has a great impact in the system, which is why you replace the desiccant in the accumulator to grab any water in the system - the oil/refrigerant/desiccant must all "match" for things to be balanced and work right.
If you just charged your system now (without an evacuation) and ran the AC, you would get vent temps no better than about 57F based upon where you are geographically located, but once you pull a complete vacuum (30-minutes minimum) your vent temps can be between 38-41F.
For people in locations where it is routinely over 98F (SW USA) you may want to keep your r12 system as the "curve" is better for mobile refrigeration. There are other refrigerants that can/are being used in the southwest, including purified hydrocarbons (like butane) with good effect - however, these are flammable. Any refrigerant other than pure r12 or r134a will not be serviceable by cooling shops - they will not want to contaminate their cylinders with an "unknown" refrigerant.
there is so much more to say...
