water in a/c system?!?
Thread Starter
Burning Brakes
Joined: Sep 2005
Posts: 832
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From: Sarasota Florida
water in a/c system?!?
so i think there's some kind of liquid like water that was in my eveporator when my friend cleaned it out for me. is there a way to get all this out or does a vaccuum pump take care of it when i vacuum out the whole system? i already used pressure to blow out as much as i could, and i don't even know if there's any in there anymore...
Tech Contributor
Joined: Aug 1999
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From: At my Bar drinking and wrenching in Lafayette Colorado
Purpose of running the vacuum pump on the system is to evacuate air and moisture. However, if you had water in the system, you should replace the receiver/dryer in addition to running the vacuum pump on the system for a while. If you really want to make sure the system is dry, you can run 1/2-pound-or-so of freon into the system after evacuation and then re-evacuate with the vacuum pump. This will get all the moisture out. 
Race Director
Joined: Sep 2001
Posts: 10,560
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From: Wellington, FL
St. Jude Donor '11 thru '25
I would just blow it out with shop air. You can't hurt it so use 100 lbs. of pressure or so until moisture stops coming out. I would apply the air to both ends of the evaporator, alternating from one to the other. When it is pumped down with a vacuum pump, I would do so for a couple of hours.
Thread Starter
Burning Brakes
Joined: Sep 2005
Posts: 832
Likes: 0
From: Sarasota Florida
I would just blow it out with shop air. You can't hurt it so use 100 lbs. of pressure or so until moisture stops coming out. I would apply the air to both ends of the evaporator, alternating from one to the other. When it is pumped down with a vacuum pump, I would do so for a couple of hours.
Race Director
Joined: Sep 2001
Posts: 10,560
Likes: 439
From: Wellington, FL
St. Jude Donor '11 thru '25
Race Director
Joined: Mar 2006
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From: Florida
Besides containing water, that liquid was probably a mixture of oil and water which = acid. Not good for the system.
Buy a can of real A/C system flush and flush the evap. Flush everything except the compressor and a new filter/dryer. At least use laquer thinner until it comes out clean in both directions.
Next put a DEEP vacuum on the system. Normal gauges cannot read this vacuum of 29.92", so if it is a good pump, just leave it on for a long time. You need this deep of a vacuum to suck out the water that turns into vapor at this pressure.
If possible I leave the pump on overnite to make sure all the moisture is out.
Buy a can of real A/C system flush and flush the evap. Flush everything except the compressor and a new filter/dryer. At least use laquer thinner until it comes out clean in both directions.
Next put a DEEP vacuum on the system. Normal gauges cannot read this vacuum of 29.92", so if it is a good pump, just leave it on for a long time. You need this deep of a vacuum to suck out the water that turns into vapor at this pressure.
If possible I leave the pump on overnite to make sure all the moisture is out.
