AC vent temperature

[inacoma]

What say ye' list on what the AC vent temperature should be in relation to ambient temperature? I could not find the spec in the FSM or archives. This is in regards to R134A, as I know R12 gets a bit cooler.

I'm reading about 50-60 degrees at highway speeds with the following weather conditions:

87°F
Partly Cloudy Feels Like
94°F

UV Index: 8 Very High
Dew Point: 71°F
Humidity: 59%
Visibility: 7.0 miles
Pressure: 29.98 inches and rising
Wind: From the Northwest at 6 mph

My AC pressures are within spec. If what I'm getting is still not cool enough, I may need to have the system professionally evacuated and recharged. There are no compressor noises, leaks, etc.

How would one diagnose if there was "air" in the system? I do have manifold gauges, so feel free to be technical on this one you AC gurus!!!

Kumar

 

[e9999]

I'll catch hell from the regulars for saying this without all the full technical details that I am now
(in)famous for, but don't have them handy right now, so by memory, it's blowing air somewhere between 42F and 48F just about for all outside temperatures seen, easily up to the 90s.
FWIW
E

 

[MrZumma]

50 - 60 degrees is a big swing. I just had my AC evacuated/recharged a few weeks ago and we just go over a hot/humid spell (Temp: 95°F , Dew Point: 70°F, UV Index 7). With those stats, my AC was running right around 48°F at freeway speeds... Could be the UV index..

I'm not an AC guru, but the FSM has excellent gauge readings for various scenarios. Shoot me a PM if you want those diagrams...

EDIT: I see you have the FSM . Page AC-8 has a drawing of what your guages would be showing if air was in the system...

 

[Doc]

42 degrees at the vent after re-charging my good 'ol R-12 system. Wow, what a difference that made!

I now make ice on the dash.... OK, not really- but I almost never have the slider all the way on cold for more than 5 minutes now.

 

[inacoma]

took a visit to goodyear

I just went to goodyear shop and they said if my low pressure (25PSI) showed good pressure and my high pressure showed too high (in my case 325PSI), then I most likely have a blockage in the system somewhere. i.e. they think it's the dryer or the orrifice tube (if our trucks have one). while tearing it apart they recommended replacing the expansion valve as well.

what say you?

For 160k miles of the life of the truck it was located in Southern California...so maybe my dryer is done for?

Kumar