Air Conditioning assistance needed
Thread Starter
Drifting
Joined: Nov 2002
Posts: 1,593
Likes: 0
From: Mobile AL
St. Jude Donor '05
Air Conditioning assistance needed
I discovered that the pressure valve on my AC unit ('96, LT1) was leaking (oil on it and when I removed it, there was no refrigerant pressure). I've ordered a new one, and it should be in today. Question: since the refrigerant has leaked out, do I need to pull a vacuum on the system, or is it OK to just recharge it? I don't know how long it's been leaking, but the AC worked fine last fall.
Maybe this belongs in Tech - Mojo, can you move it?
Maybe this belongs in Tech - Mojo, can you move it?
Burning Brakes
Joined: Jul 2003
Posts: 811
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From: OH
St. Jude Donor '06-'07-'08-'09
Did you leave the system open to the atmosphere or did you reinstall the old valve until you get the new one? If you left it open - you should probably change out your receiver-drier as well (and replace any oil that might be inside)- the dessicate inside the drier will become saturated with moisture from the atmosphere. Either way - you will need to pul a deep vacuum on it to boil out any moisture in the system.
Good luck
Good luck
Racer
Joined: Oct 2003
Posts: 429
Likes: 0
From: Plains Ga.
airconditioner
I suggest that you replace the accumlator, orifice (type of filter), flush the system completely and then add oil per instructions. Put all the parts back in place. (You might want to assemble the parts prior to the oil and pull a vaccum to test for leaks.) Then pull (another) vaccum and start adding freon.I usually jump the low pressure switch wires out with a piece of wire to get the compressor to engage it's clutch when charging the system. I do this until the switch can cycle the clutch on and off by itself.(remove the jumper and plug up the wire every now and then.)
Pro
Joined: Oct 2003
Posts: 506
Likes: 12
From: Savannah GA
It might be a good idea to replace the scharder valves. They are one of the biggest causes of refridgerant loss. Get good ones for AC.
Did it have even a little pressure when you started? That might let you know if the system was contaminated.
Some of the R134a AC oils are real bad about absorbing moisture. That's why it was suggested to replace accumlator, orfice and flush system.
If it holds a vaccuum you can recharge and it will cool. If the desicant is contaminated the water will form acids and cause corrosion in the system.
There is a AC info web page, it has good info.
JS
Did it have even a little pressure when you started? That might let you know if the system was contaminated.
Some of the R134a AC oils are real bad about absorbing moisture. That's why it was suggested to replace accumlator, orfice and flush system.
If it holds a vaccuum you can recharge and it will cool. If the desicant is contaminated the water will form acids and cause corrosion in the system.
There is a AC info web page, it has good info.
JS
Thread Starter
Drifting
Joined: Nov 2002
Posts: 1,593
Likes: 0
From: Mobile AL
St. Jude Donor '05
There was a little hiss when I punched the valve, so was not open to atmosphere. Took it to dealer on Saturday, shared all your comments, they checked the system out, replaced the little filter just before the evaporator, pulled vacuum, no leaks, filled with refrigerant, and again, no leaks, so is repaired for the moment. Thanks for the tips.
