I have a 2004 Malibu 2.2L 4 cylinder. My AC system was recently drained from the compressor drain plug. The system was functioning properly prior to being drained, so I don't need any new components, but I do need to replace the oil and refrigerant charge in the system. Can the oil be sucked into the system through manifold gauges? Or should it be added directly into the compressor or another component? Also how can I tell if my system is completely drained of oil?
Thanks in advance for any advice anyone can provide!
To get the oil in; you use a tool that injects the oil in. There are a few different kinds; one type connect between the gauges and the service port. Sense you have no refrigerant in the system you can take out the valve and poor the oil in.
Now the problem is knowing how much oil is in the system. there is really no way to really know. the best way is to add as much that came out. There is a service chart the lets you know how much to add per component changed but that is not your issue.
The other problem is how long has the system been open? You may need to change your dyer. If you don't there is a chance you may kill your compressor if there is moisture left in the system. Most people think when you pull a vacuum on the system it gets all the moisture out but that is not true. There is really no was to pull a perfect vacuum. So there is always gas left in the system.
Also make sure you get PAG oil, there are different weights, so it is best to get the one made for gm but it will not cause any major problems if you can't find it or get it.
Thanks for the reply! Which valve are you referencing?
I didn't measure the amount of oil that came out of the system, so I have no idea how much is currently in there. Should I just replace the recommended amount for compressor replacement, since I drained from the compressor?
My system was only open for about 10-15 minutes, would that require changing the dryer? On my model the dryer is integral with the condenser coil, so I hope I don't have to replace the whole thing...
The valve I was referring to was the schrader valve, it is the little pin in side the service ports. The tool to remove it is really cheap you can pick it up at any auto parts store. and it would be a good place to start to just add the recommended amount for a compressor change.
When they removed the plug from the compressor was the system full. If so them the gas was released it pulled some oil from the rest of the system. so if this is your case add about 1/2 oz per lb of refrigerant on top of what is needed for the compressor.
And when pulling a vacuum on the system, let the vacuum pump run for at lease 30 mins, even thou it will go down to 29.92" Hg of vacuum in like 1 min. and mark the gauge and let the system sit for like 30 mins untouched to see if the gauge moves at all. If it don't move you are good no leaks and its ok to refill the system. And when you add refrigerant make sure you add it by weight not pressure.
I would not worry to much about the dryer just make sure you get a really good vacuum on the system to make sure you get as must air out of the system as you can and remember you can't run the vacuum pump to long. On some jobs I had to use two pumps and let them run all night long to get the system down to 300 microns.
Also, it maybe a good time to think about changing the orifice tube filter and the compressor filter as well because they are so cheap and the system it open. Its just good insurance.
If you have an other questions I will try to help, but I really don't do automotive A/C work. I have done it on my own cars but other then that I have not done any, but I do, do industrial and commercial work for a living, so for the most part they work the same just different gases and systems.
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