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A/C blows warm air

Macc

Full Member
Joined
Jan 20, 2013
Messages
26
I have an 02 2500 Avalanche and this summer my A/C  hasn?t been working the way it should. About a year and half ago I replaced the compressor because it failed. It worked perfect and was ice cold all the way up till this summer. Now it will blow cold air in the morning but in the afternoon it will blow warm air especially sitting in traffic. Even driving at 60+ mph in the afternoon it doesn?t get cold. It?s cooler then it is during traffic but not even close to the way it used to be. Does anyone have any suggestions?
 
When you replaced compressor did you flush the lines and change expansion orifice screen thingy?

What pressures are you seeing on hi and low pressure ports?

How is fan clutch?
 
My buddy who?s a mechanic replaced it for me I?m not sure if he flushed out the lines or not but I know he cleaned the screen thingy. I?m not sure how much pressure I have as I don?t have a anything to test it with. As far as I know the fan clutch is working fine. I?ll have to open the hood and watch it while it?s running to verify.
 
Time to borrow some gauges from your mechanic friend! Step 1 is to verify pressure (ie. refrigerant levels) inside the system as ygmn noted.
 
Unfortunately I have since moved out of the area so I cannot use his gauges. But I can pick up some of my own. What are the gauges that I will need? So I know what to look for
 
A/C R134A Manifold Gauge Set, if you don't mind Harbor Freight you might consider this set
https://www.harborfreight.com/ac-r134a-manifold-gauge-set-62707.html

Scotty will show you how it's done
https://www.youtube.com/watch?v=80jSH8VQZms

Pressure chart
134a-pressure-chart-templates-world-intended-for-ac-pressure-chart-for-134a.jpg


Edit: maybe this will help too
r134apc1-300x196.jpg
 
Thanks a lot. Yeah I?ll probably go buy that one from harbor freight tomorrow
 
Macc said:
... As far as I know the fan clutch is working fine. I?ll have to open the hood and watch it while it?s running to verify.

You can't tell if the fan clutch is working properly by watching it run.

You can get a rough idea if it is worn out if, while cold and with the engine not running, you try to spin the fan by hand.

If the fan spins freely, the fan clutch is worn out.

If the fan resists spinning freely, the fan clutch may be OK.

If that fan clutch has not been changed in the past 5 or 6 years, I would go ahead and replace it with a severe duty version of the fan clutch.

I change mine that often for good measure and they do wear out over time.

And I am not interested in changing mine over to electric fans, though some members swear by those.

To each their own, I suppose.
 
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