A/C air temp (Page 2/2)
donuteater306 JUL 29, 11:21 AM
Thanks you guys for the help. That breakdown of the pressures is impressive, I took a screenshot for future. Ironically, I had replaced the heater core a week or two prior to the A/C service and although I did not touch the blend door or cable, I didn't check them either. 35 years of movement they could easily be loose or out of adjustment. It's been several years since I checked for leaves or other crap near the fan resistor. I'll do that this weekend and get a good look at the evaporator. 50 deg. isn't horrible, i mean...that was a 50% reduction from outside. Just that in previous years my little pen thermometer would read in the 40's at freeway speeds. I'll report back...thanks again.
sanderson231 JUL 29, 01:24 PM
If the system cycles while parked holding 2000 rpm but the evaporator outlet tubing is not cold (should be about 40 'F), it is a sign of a partially plugged orifice tube or the screen ahead of the orifice tube. Another sign is lack of condensate from the evaporator drain (your A/C guy mentioned this). The vent temperature will also high due to the reduced flow of refrigerant. I always replace the orifice tube assembly whenever the system is evacuated (as little as $0.41 at Rockauto).. The pressures can look normal with a partially plugged orifice tube.

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formerly known as sanderson
1984 Quad 4
1886 SE 2.8L
1988 4.9L Cadillac
1988 3800 Supercharged

donuteater306 JUL 31, 01:29 PM
So, I actually have a new orifice that I was going to install but didn't because everything seemed to be working ok. The way things usually go fo me is "if it ain't broke, fix it till it is" hahaha didn't wanna risk it. What's weird is, the lines and dryer are cold and sweating. Today I'm going to inspect inside the housing to make sure there are no nests or any other fire hazards, then just drive it a good hour with it blowing.