Stupid but technical AC questions --- PLEASE READ!!
07-26-2008 | 04:28 PM
#1
Thread Starter
Nordschleife Master
Joined: Dec 2007
Posts: 7,100
Likes: 7
From: Las Vegas, NV
Stupid but technical AC questions --- PLEASE READ!!
OK, I'm working on my Honda Civic AC system. I have a venturi vacuum pump which works great, but my compressor isn't big enough to let it run constantly. I pump up a vacuum in the system (27in at 2500ft ... not to bad) then I close the valve on my gauges and let it sit with a vacuum. I come back an hour or 2 later, and pull vacuum again.
I did this for 2 days. The vacuum stays in the system constantly (no leaks) but I pull a vacuum every couple of hours to try to try to get out all of the boiled water and stuff.
So these are my questions.
When I pull a vacuum, am I also getting rid of the oil in the system? I'm afraid I added to much oil the 1st time I did this, because when ever I turned on the AC, it about stalled the engine. I can turn it by hand, but at engine speeds, its quite a load..... The 1st time I did this, I added 2 cans of oil (4oz ... system only takes 3.... so I know it was over full, but if it had the origional 3oz in it, then it could have had 7oz?????) and a can of freeze 12 (for a total of 16oz of refrigerant). I thought my initial vacuum would remove all the oil so I added more, but then it seemed like the pump was working extra hard (trying to compress too much oil???), so I evacuated it again, and pulled a vacuum for 2 days.....
So, if I'm not getting the oil out by vacuuming, is there another way to get the oil out other than removing it from the car? I removed the hoses from the compressor, and blew air through it, and it spins free, and no oil came out. I even tried to suck it out with some silicone vacuum hose......nothing. So is it safe to assume all the oil is out, and I can start again????
I'm going to sell the car, so I'm not wanting to put hours and hours into this. I just need the AC to "work". I'm not trying to screw anyone. I want it to be reliable, but it doesn't have to be 100%.
I did this for 2 days. The vacuum stays in the system constantly (no leaks) but I pull a vacuum every couple of hours to try to try to get out all of the boiled water and stuff.
So these are my questions.
When I pull a vacuum, am I also getting rid of the oil in the system? I'm afraid I added to much oil the 1st time I did this, because when ever I turned on the AC, it about stalled the engine. I can turn it by hand, but at engine speeds, its quite a load..... The 1st time I did this, I added 2 cans of oil (4oz ... system only takes 3.... so I know it was over full, but if it had the origional 3oz in it, then it could have had 7oz?????) and a can of freeze 12 (for a total of 16oz of refrigerant). I thought my initial vacuum would remove all the oil so I added more, but then it seemed like the pump was working extra hard (trying to compress too much oil???), so I evacuated it again, and pulled a vacuum for 2 days.....
So, if I'm not getting the oil out by vacuuming, is there another way to get the oil out other than removing it from the car? I removed the hoses from the compressor, and blew air through it, and it spins free, and no oil came out. I even tried to suck it out with some silicone vacuum hose......nothing. So is it safe to assume all the oil is out, and I can start again????
I'm going to sell the car, so I'm not wanting to put hours and hours into this. I just need the AC to "work". I'm not trying to screw anyone. I want it to be reliable, but it doesn't have to be 100%.
07-26-2008 | 06:23 PM
#2
Pro
Joined: Aug 2007
Posts: 692
Likes: 1
From: Eastern PA
The oil won't boil out. You will have to take the compressor off as well as the accumlator because that too holds oil in it. Not the news you were looking for, but that how it has to be done. You don't have to change the oil everytime you charge the system, only if you are converting from R-12 to R-134a.