Just bought a 2002 GMC Sierra 6.0L yesterday. I noticed the A/C didnt cool. Got home and noticed the belt was missing for the A/C compressor. The pulleys were really rusty so the belt must have been missing for a while. All the pulleys spun fine by hand. Turning the compressor by hand, it felt fine as well. So I bought the belt this morning and put it on. Hooked my guages up and low side had 160 psi with it off, and when it kicked on, it dropped down to around 100. The lines were starting to get cold. I was sitting in the truck and it starting making a weird noise. The air blowing out started getting really hot. I felt the lines after I shut it down and all the lines were too hot to touch. Even the line after the orfice tube was hot. I think the dealer didnt notice the belt was missing, and just pumped it full of refrigerant trying to get it to work. Does it sound like its overfilled to you guys? Thanks in advance!!!
02 GMC Sierra A/C Not Cooling
- Thread starter ChevyGuy3100
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OK it would be hard for anyone who can figure out how to open the hood to miss a belt that is not there assuming the dealer looked over the vehicle. I would remove the belt and take it back and say the A/C does not work.
A dealer should have a machine the evacuates the system, checks to see a vacuum is held for 30 minutes, then refills the system by weight of refrigerant.
You should have some kind of warranty by state law from a dealer.
A dealer should have a machine the evacuates the system, checks to see a vacuum is held for 30 minutes, then refills the system by weight of refrigerant.
You should have some kind of warranty by state law from a dealer.
Its not necessarily a dealer... a used car dealer. They have no garage. They just sell them. It was kinda easy to look over the missing the belt. Its all the way at the bottom hidden under a bunch of plastic. Sticker on the window says "As is-No warranty." Its 14 years old with 90,000 miles.
We worked on my dad's 07 Chevy truck a/c last weekend. S.hould be the same as yours (and most all others, not much variability). The low side should be in the neighborhood of 35 to 45 lbs. when running about 1500rpm, and the high side ~195 to 220 or so. You really need to check both sides to make sure it's all hunky-dorey. If it has sat a long time w/o working, that means no lubricant has circulated and seals may not seal any longer once you get it operating.
Usually, when the belt is removed, the compressor is seized and caused the belt to seized and caused other pulley not to turn.
You need an AC work.
There is Pressure Temperature Chart for R134A refrigerant and as said the range should be around 35 to 60 psi. 60 psi is if the temp is really hot like 100F.
You need an AC work.
There is Pressure Temperature Chart for R134A refrigerant and as said the range should be around 35 to 60 psi. 60 psi is if the temp is really hot like 100F.
Compressor belt missing is usually for a good reason.
Kind of good that they didn't try to work on it. Even so, with a used car you risk getting into all kinds of weird stuff like stop-leak.
The static pressure-- NOT running, and truck has been parked with engine off for a long time, not in the sun, so all parts can be assumed to be at the same temperature-- should be about the saturation pressure. Static pressure above the saturation point indicates there is air mixed with the refrigerant.
Emptying the system to a vacuum then recharging it by weight is the best place to start with a case like this. Then run the compressor and observe both pressures.
Kind of good that they didn't try to work on it. Even so, with a used car you risk getting into all kinds of weird stuff like stop-leak.
The static pressure-- NOT running, and truck has been parked with engine off for a long time, not in the sun, so all parts can be assumed to be at the same temperature-- should be about the saturation pressure. Static pressure above the saturation point indicates there is air mixed with the refrigerant.
Emptying the system to a vacuum then recharging it by weight is the best place to start with a case like this. Then run the compressor and observe both pressures.
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I recovered the refrigerant and recharged it. It was 21oz overfilled. Im almost positive the dealer tried to get it to work by pumping more refrigerant into it, unaware that the belt was missing. It works great now. Its 90*F outside an after a few minutes, it blows 38*F!! No more noise. Maybe the previous owner towed a lot and just took the belt off to save the drag?
Originally Posted By: ChevyGuy3100
It was 21oz overfilled. Im almost positive the dealer tried to get it to work by pumping more refrigerant into it, unaware that the belt was missing.
Gee that's fricken weird as all heck. Definitely doesn't help the reputation of dealers.
It was 21oz overfilled. Im almost positive the dealer tried to get it to work by pumping more refrigerant into it, unaware that the belt was missing.
Gee that's fricken weird as all heck. Definitely doesn't help the reputation of dealers.
I had a 02 Sierra and the A/C abruptly quit at about 50k miles. I looked under the hood and saw the serpentine belt intact so I brought it by a shop a friend worked at. He asked if I checked "the belt" then pointed out the tiny hidden compressor belt that was missing and I didn't know to look for.
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