How to recharge your AC

[KPOD]

I kinda just assumed that these "threaded charge ports" is what I needed? http://www.rockauto.com/catalog/x,c...e.com+Search+for+1998+CHEVROLET+TAHOE+5.7L+V8

 

[SunlitComet]

Hi kpod i got your message. In you case get that whole screw in body you linked me on rock auto. It should have the valve already in it. If not get a delco replacement as well until then cap it immediately to prevent contaminants from getting in. There is another concern tho. If it has come to the possibility that the system has been leaking so bad that atmosphere has been able to get it get a new receiver/dryer. If not and there is still some refrigerant under pressure, be very quick about changing that valve and evacuate the system for at least an hour with a minimum of 28-29 ingh before inserting new refrigerant. This will ensure all the moisture in the system is out and won't cause acidity problems later.

 

[KPOD]

Hi kpod i got your message. In you case get that whole screw in body you linked me on rock auto. It should have the valve already in it. If not get a delco replacement as well until then cap it immediately to prevent contaminants from getting in. There is another concern tho. If it has come to the possibility that the system has been leaking so bad that atmosphere has been able to get it get a new receiver/dryer. If not and there is still some refrigerant under pressure, be very quick about changing that valve and evacuate the system for at least an hour with a minimum of 28-29 ingh before inserting new refrigerant. This will ensure all the moisture in the system is out and won't cause acidity problems later.

Alright, I don't think the valve comes with the schrader valves, so I'll order both. Found the AC Delco receiver/drier as well. I'm fairly confident there is no refrigerant left in the system as when I hook up a pressure gauge to the low pressure valve (with the motor off) I get a 0 pressure reading (I should get at least something if there was refrigerant left in the system I think?).

What do you mean by "If it has come to the possibility that the system has been leaking so bad that atmosphere has been able to get it get a new receiver/dryer. If not and there is still some refrigerant under pressure, be very quick about changing that valve and evacuate the system for at least an hour with a minimum of 28-29 ingh before inserting new refrigerant." So if it is already completely empty, is there really anything to dry out? I'm assuming I should re-fill on a hot, non-humid day so any condensation in there will have dried out? What do you mean 28-29 ingh?

 

[SunlitComet]

Forget what i mean.about if it has been open to the atmosphere you just answered that. If you got zero the system has been exposed to the atmosphere. Get the dryer and have the system parts repaired as needed. Put on the dryer and evacuate the system for a minimum of 1 hr. The dryer would have been ruined for moisture in the atmosphere getting in the system. It can only trap so much moisture before it becomes ineffective. By now you have moisture in there. The dryer will protect the next charge going in and evacuating the system will lower the boiling point of moisture that it will just evaporate and go out the vacuum pump as well. 28-29 inches of mercury. It is a unit of measure for vacuum. Once evacuated dispense the refrigerant into the system while it is still under vacuum do not release the vacuum in the system first otherwise plain air will get right back in. the refigerent going in will let the vacuum disapear and the pressure start rising. you can recharge it on any kind of day you want but there are specific readings on the gauge set you should see as well as certain temps inside the center dash vent on any specific outside air temp humidity combination reading.

 

[Sakamoto]

Recharging my 02 Yukon was a snap after reading this thread! Thanks so much for this great info!

***EDIT***
Well I ran into a snag and hopefully someone can help me figure it out. I finished the first can and it was going down to 20psi and up to 50psi. Ambient temp was 82F. according to gauge it should have steadied out between 40psi-50psi but it isn't. It is staying at 20psi to 50psi. The vent temp is still way hot. After driving it a couple of miles the vent temp goes down to 68F if that makes a difference. Also I took the gauge/hose off the second can and it didn't have the pssst sound like it had not even punctured the can and if feels full of freon and oil.

Hopefully one of you can tell me what I'm doing wrong or at least point me in the right direction.

 

[96-2D-Hoe]

Bit late to reply, but it sounds like you don't have enough gas in there yet. My 96 takes 3lbs from empty. If when you are charging it up the compressor is cycling on and off then it is still short of gas.

Recharging my 02 Yukon was a snap after reading this thread! Thanks so much for this great info!

***EDIT***
Well I ran into a snag and hopefully someone can help me figure it out. I finished the first can and it was going down to 20psi and up to 50psi. Ambient temp was 82F. according to gauge it should have steadied out between 40psi-50psi but it isn't. It is staying at 20psi to 50psi. The vent temp is still way hot. After driving it a couple of miles the vent temp goes down to 68F if that makes a difference. Also I took the gauge/hose off the second can and it didn't have the pssst sound like it had not even punctured the can and if feels full of freon and oil.

Hopefully one of you can tell me what I'm doing wrong or at least point me in the right direction.