So I have had my car in and out of the local Chevy dealer in my city. I paid $2300 to get the compressor and evaporator replaced in my car (2000 Corvette 6 speed). Out of the last 4 and a half months they have replaced not only the compressor/evaporator, but also the condenser, accumulator and orfice tube. I feel as if 60-70 degree air on a 90 degree day isn't nearly as cold as it should be, they say it's correct that GM says it should blow 20 degrees cooler (so if it's 80 outside it should blow 60). What do you all think my air should blow since it's basically a completely new AC system minus the actual lines? The coldest I have gotten it down to after driving it for an hour on a 90 degree day and parking in the shade with AC on full blast in the middle vent and as cold as it goes was 65 degrees...

 

From my 02 Manual: With the drivers window open 6 in and passenger closed, blower on high, A/C in recirculation, after 5 minutes the center A/C outlet temp should be 50 to 52 degrees with ambient at 86 to 95 degrees.

I do all my maintenance on my 02 with 135K miles, so when the AC went out recently I decided to go on a new learning project starting at ground zero for AC knowledge. Below are my experiences.

First I read the manual. It states most leaks occur at at O ring connections, service port valves, and sensors. It appears from Web comments, the most common leaks on our Vettes are the service port schrader valves and O Ring connections to the compressor. And of course rock damage to the condenser. And you pray it is not the evaporator.

First I bought a gauge set ($45), and yes the freon was very low. There is dye in the system from the factory, so I bought a pair of UV glasses and a light ($15). I could not detect the leak, so I added a can of freon to get the compressor to run. And made my first mistake, I did not purge the air from the yellow charging hose. It is interesting to note the number of you tube videos and AC gauge set instruction booklets which do not mention that. It simply meant I would change the accumulator ($20) once the leak was found.

When I removed the gauge set, I saw a lot of dye around the service ports. I decided to buy a vacuum pump ($100) and service port schrader valve kit, and replace both service port valves ($8 with new caps). With the pump, I could draw a vacuum on the system, and test if the vacuum remained overnight. Which it did...meaning I had probably fixed the leak. So I replaced the accumulator and orifice. Then made mistake 2: the AC Delco brand accumulator came with two new O rings but they were different than the original O rings. I ordered a complete O ring kit ($8) while I installed the accumulator with the supplied ones. And sure enough, the vacuum did not hold, so I replaced the O rings with the correct sized ones from the kit, and the vacuum held. After running a vacuum overnight, I added two cans of R134a (1.5) lbs, and all pressures and temps were right on. Yeaa

Other notes: when adding freon, wear eye protection and gloves, and never open the high side manifold. I saw a lot of U tube videos suggesting using PAG oil to lube the O rings when Nylog or mineral base 525 is the correct lube. I needed to add two oz of PAG oil to the new accumulator. My 02 came with PAG 150 in the system. In 03, GM switched to PAG 46, and suggested that for going forward, so I used PAG 46.

Going forward, now that i sort of know what I am looking for, I am going to measure the static pressure twice a year to detect a leak early on. And I suggest if you have an AC issue, buy the UV glasses and light even if you will have it serviced else where. In many cases the leak will be evident since GM put the dye in the system, and it will give you confidence in the service department diagnostic.

 

Your system is either overcharged, undercharged, not getting enough airflow or the compressor that they replaced the original with is bad. Sounds crazy, but my buddy replaced his a/c compressor and I charged and recharged that system numerous times, replaced his cooling fan assembly, pretty much everything under the sun. Turns out, the replacement compressor he bought wasn't up to the task. Swapped compressors, charged it once and it blows ice cold.

Take compressed air and blow out your radiator and condenser. Remember if there is a blockage to the radiator it will hinder air flow to the condenser.

Buy a set of manifold gauges for 50 dollars and check your current high and low side pressures, or take it to a local mechanic shop and have them check it quick, you will quickly be able to tell if your system is overfilled. Stop paying the stealership crazy money to do half *** work for you.

If your pressures are fine, and your airflow is good. Swap the compressor.

For instance, my procharged 850 rwhp vette with minor cooling issues will blow 45-50 degrees on a 95-98 degree south carolina day while driving around (parked is about 55).

use the chart below if you buy a set of manifold gauges. I have used a set from harbor freight for years without any issues.
http://www.harborfreight.com/a-c-man...set-92649.html





https://www.corvetteforum.com/forums...actuators.html also worth a good look.

 

Thanks for getting back and sorry it took me a couple days to reply. So as I have been continuing to fight with the dealership to get my money refunded to me due to my car being in worse shape now than it was in April when I first took it down to get fixed, I will go and get a set of AC gauges and check my pressures tomorrow and will post back on here as soon as it do with any other info that might help me fix this issue. Thank you

 

Just checked the pressures on my AC and they were:

High side- 135psi

Low side- 44psi

Also pulled the codes to see if I had anything and I had a
90-HVAC B0361 H

Its 72 degrees outside when I checked the pressures and and the temperature of the air coming out of the vents was 58-60 degrees.