Does this AC need recharged??

[FADEC]

Turned the AC on today in my vehicle for the first time this year. I have a thermometer in my center vent. It never got below 50f for my entire drive which included a mix of city and highway driving over about an hour. The air never really felt cold just cool. The ambient temp was 84F. Pretty much ran it on high/medium high. To those in the know about AC, does this seem correct??

The vehicle is a 2009 Chevy Avalanche 5.3l.

 

[jrustles]

Did you bring the engine speed above idle? If so, was it any colder? Were the condenser fans running?

From just what you describe, it seems that the charge maybe slightly low, but still within tolerances. Some people will consider a ~35degree drop to be "acceptable", but personally I'd prefer at least 15degrees less.

 

[JHZR2]

AC should be run at least one a month to maintain lubrication of seals and prevent refrigerant loss.

A static and operating pressure test is the only way to tell. It is warm today in NOVA. Im on the other side of the American Legion Bridge today and it is 82 outside.

 

[UNC017]

Was the temp control actually set at FULL cool? Ill confess to sometimes wondering why the Jeep AC wasn't really blowing cold after work, then remembering I had a little heat dialed in on the way to work that morning.

 

[Fleetmon]

The suction line (the big line) should be very cool/damp and the little line should be hot....if not, it probably needs attention. Use a hose and squirt off the condensor while its running and see if the suction line gets a lot colder. If it doesn't get appreciably colder, then yes, it is probably low.

Like jrustles said though 50'F isn't real bad....you still have greater than 30'F less than ambient.

 

[FADEC]

Yes the engine was well above idle. I was on the interstate for awhile then some side roads.

Yes the AC is in full cool mode. It has auto climate control and it was set at 60f(the coldest setting).

My last vehicle was an 2002 silverado and it was not uncommon during a long drive for the AC temp to get in the mid to upper 30's. LOVED that AC.

 

[FADEC]

Just checked it now in the driveway idling.

Vent temp was 60f after about five minutes idling.

Electric cooling fans were cycling on and off.

Suction was cool I guess, but small line was not hot, actually slightly cool.

 

[rshaw125]

My old van blows 39 degrees from the center vent when it's 90 degrees outside. I run a 134A replacement, Envriro-safe.

 

[mattd]

You need to put a set of gauges on it. Frequent cycling is a sign that the system is low on charge.

 

[Fleetmon]

Is the compressor cycling on and off? That is usually one of the signs the system may be a little low.

Have you ever used the little "kits" that are available at the auto parts stores? AC is a little tricky but if it just needs a little sniff to bring it up to snuff, it is well within a DIY repair....follow the directions and wear safety glasses. However, with that said, the BEST way to fix it is to use someone that knows exactly what they are doing....using the little kits only contains one-half of the tools you truly need and the directions cannot possibly teach you how air conditioning works and why it works. Plus, there is a very real potential to get blinded or suffer frostbite if you handle refrigerant improperly!

MOST people screw up by adding too much refrigerant and it will NOT cool at all with too much refrigerant....this is definitely a case where a little more is NOT good!

If you choose to go down the DIY road, go slow and add a little at a time, close it up and road test, and add more if needed....if you get your vent temps down to 35'F or so sitting still in your driveway you have probably added too much and your "repair" will backfire on you.

 

[GMBoy]

Quit guessing and check the charge with a gauge. Bottom line. It does sound like a tiny bit of charge could be needed..but adding too much will also mess you up with warmer air so be careful. I would also have a leak test done since a 2009 should not have lost any charge. I you "must" add some yourself please have the temp gauge in the center dash vent and only add 1/4 can and stop there. See how it goes so you don't overcharge..just like some others said.