A/C Pressures
A/C Pressures I am picking up a car tonight that needs some A/C work. I have the manifold an gages and all that stuff, but what should the pressures on the Hi and Lo sides be?
I am sorry I can't be much of a help. I know my method does work. I remember from Thermodynamics that the condensor is most efficent when under near vacumn. That means Reverend Chaos probably has about the right numbers. When designing you want the biggest temperature differential possible.
Are those numbers static or with the car running? I repaired my a/c, evacuated, and recharged with 24ozs. A/C works, but I wanted to compare. I think my low side with the car running on max was 60 psi and my high was 150.
If the AC isn't running the pressure should be the same throughout the whole system. So yes those are running numbers.
When you evacuated the AC did you leave it at near-complete-vacumn for a couple of minutes? I always wait about 15 min and see if the gauge moved to test for leaks.
When you evacuated the AC did you leave it at near-complete-vacumn for a couple of minutes? I always wait about 15 min and see if the gauge moved to test for leaks.
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lol 
I ran across the actual page from the service manual. Based on the weather conditions last night, my lo should have been 30-40 psi and high should have been 150-210.
I performed the check per the service manual....at 2 min my low was at 35 psi and my hi was at about 130. At 6 min, the hi finally came up to 150. A/C is definitely not blowing ice cold.
Is my compressor on the way out?
I performed the check per the service manual....at 2 min my low was at 35 psi and my hi was at about 130. At 6 min, the hi finally came up to 150. A/C is definitely not blowing ice cold.
Is my compressor on the way out?
Today's vehicles don't use a stand alone expansion valve. What he means is a throttling valve with a mechanical tempurature controlled switch. Today's cars just use a throttling valve since everything is electronic.
Well, I should have said defuser (oppisite of nozzle) not valve. Nozzle being a large orifice leading to a small orifice. Defuser being a small oriface to a large oriface. The point of the defuser is just to slow down and expand (lower pressure) of the R134A before it reaches the condensor.
I don't know the exact physical spot however all automotive systems work on the same refrigeration cycle. Start at the condensor and trace the AC lines towards the evaporator. It is between those two parts. It could even be part of the evaporator. I really don't think you would have to troubleshoot anything if you can get the system working first.
If you fill the system and it holds the charge and isn't working then I would take it apart and check for clogged filters.
If you fill the system and it holds the charge and isn't working then I would take it apart and check for clogged filters.