AC System

So its that hot time of year again. Got a question I cant seem to find an answer to.

My A/c Quit working after a year of owning my 2003 Silverado with the 5.3L so I broke the system apart and flushed all lines, condenser, and evaporator. Upon re-assembly i installed a new accumulator and expansion valve. Worked like a champ until next summer. I lost my freon over the winter months, so upon trying to recharge the system I got about 6oz roughly in the system and the low pressure switched kicked and not even after about 10 oz the low side pressure was at 100psi with the temp outside about 95+ Degrees. So i stopped adding freon.

I noticed that the line going into the evaporator was condensing, nice and cold with water pouring off of it. And right after the expansion valve it was hot! So everything seemed to be working on that end fine. Now the line coming from the evaporator to the accumulator is still the same temp as outside.

So my question is, is my condenser stopped up now? I failed on checking it while i had the system apart this morning. I do know that the evaporator has full flow when i blew -40 degree dry air through it. (Ouh, i replaced the accumulator again this morning thinking it was packed with moisture and too much oil, didnt help a thing) Pulled a vac on it for about a hour, and it would still only hold less than a 12oz can of freon.

Any suggestions? Thanks for your time! And sorry this post is so long and if i took you through circles while reading it lol

not sure if you have a problem or not,if you stopped charging because of pressure
being high or you cant get any more in.
1st did you repair the leak causing the loss of freon over the winter?
did you check that the system holds a vacuum after you evacuated the system?
your running engine while charging right?
you can try putting the freon can in a pot of hot water or shake the can up
if its the low side pressure reading being to high so you stopped i would'nt be concerned to much until the systems fairly full.

not sure if you have a problem or not,if you stopped charging because of pressure
being high or you cant get any more in.
1st did you repair the leak causing the loss of freon over the winter?
did you check that the system holds a vacuum after you evacuated the system?
your running engine while charging right?
you can try putting the freon can in a pot of hot water or shake the can up
if its the low side pressure reading being to high so you stopped i would'nt be concerned to much until the systems fairly full.

I found a bad seal on one of the lines, seen oil around the connection so i assumed it was it. It did hold a vac after chaning that o-ring. The engine / compressor was running the whole time. The compressor isnt cycling on and off, it just runs constantly. I did notice though after i took my truck down the road it started blowing ice ice cold. Before it felt just like a fan in the sun while idling. Took another reading on the low sidem its still about 95psi with only about 10oz of freon in the system. Thats what i dont understand is nost systems hold what, about 24 to 30 oz? Mine is cooling with 10 while moving.

I found a bad seal on one of the lines, seen oil around the connection so i assumed it was it. It did hold a vac after chaning that o-ring. The engine / compressor was running the whole time. The compressor isnt cycling on and off, it just runs constantly. I did notice though after i took my truck down the road it started blowing ice ice cold. Before it felt just like a fan in the sun while idling. Took another reading on the low sidem its still about 95psi with only about 10oz of freon in the system. Thats what i dont understand is nost systems hold what, about 24 to 30 oz? Mine is cooling with 10 while moving.

to properly figure out what the problem is , you need the low and high side pressures with both doors open and the ac on max cooling..idle must be 1500-2000rpm...

IF THE LOW SIDE PRESSURE IS 100PSI THATS ALL ITS GONNA TAKE ON REFRIGERENT !

That however does not mean you are over charged....good chance the compressor is damaged...if the compressor cannot pump this is what you get..the high side pressure would be required , to fully understand whats broke !

system takes about 32 oz...check underhood sticker for the correct amount..high side pressure will show if it is properly charged...

IF THE LOW SIDE PRESSURE IS 100PSI THATS ALL ITS GONNA TAKE ON REFRIGERENT !


If the compressor is running, and you put the can into hot water like inafogg suggested well over 100 degrees, the refigerant will go into the sytem because the pressure in the can will be higher than the system pressure. You can even fill it with the vehicle without it running as long as you keep the refrigerant you are adding at a higher temperatue than the pressure on the gauge. The hot water method works great. When you close the low side gauge valve while charging does the pressure eventually go down? With the truck system pressure and the pressure from the can the gauge will tend to stay reading high if the gauge valve is open or until the can is empty.

If the compressor is running, and you put the can into hot water like inafogg suggested well over 100 degrees, the refigerant will go into the sytem because the pressure in the can will be higher than the system pressure. You can even fill it with the vehicle without it running as long as you keep the refrigerant you are adding at a higher temperatue than the pressure on the gauge. The hot water method works great. When you close the low side gauge valve while charging does the pressure eventually go down? With the truck system pressure and the pressure from the can the gauge will tend to stay reading high if the gauge valve is open or until the can is empty.

When i close the valve on the can the gauge still reads 95PSI I wish i could get a reading on the high side, but accidentally broke that gauge :/ manifold gauges arent cheap anymore.. Odd thing, this morning the AC was actually blowing extremely cold, id say better than when i first got the vehicle. Did actually play close attention to the compressor and it doesnt sound normal so im assuming it is failing. I cant exactly describe the noise but it sounds like a normal AC Compressor running, but louder.

Have you ever taken the orifice out? A missing orifice (rare) will cause equal pressures as will a failing compressor. When the crankshaft fails the compressor cannot suck or pump and create the pressure differential needed for efficient cooling. A high side reading would be nice to identify possible cooling fan issues etc.

When i close the valve on the can the gauge still reads 95PSI I wish i could get a reading on the high side, but accidentally broke that gauge :/ manifold gauges arent cheap anymore.. Odd thing, this morning the AC was actually blowing extremely cold, id say better than when i first got the vehicle. Did actually play close attention to the compressor and it doesnt sound normal so im assuming it is failing. I cant exactly describe the noise but it sounds like a normal AC Compressor running, but louder.

a noisey compressor is with internal damage or needs a few ounces of pag 150 refrigerent oil which can be purchased in a charged cylinder for adding ....

a/c manifold set can be repaired by purchasing a new high side guage for 20-30.oo ....

GUAGE LOOK HERE = http://www.bestbuyautoequipment.com/Robinair-ROB11795-p/rob11795-01.htm

For a quick check, switch the hose for your high pressure gauge to your low pressure gauge fitting on the manifold. This way you can connect to the high side service port and get some kind of pressure reading. Your gauge should be fine because the increments are usually big up until about 120psi then there is a short area up to 350psi. If the high side also hangs around 95psi with the compressor on there is a good chance you have a compressor concern.