A/C leak fixed system will not accept charge.

[AnimalMother]

Hi. New to this forum. 2013 Tahoe 5.3 with rear a/c. So the a/c has not worked since I have had the vehicle. Found and fixed a leak in the usual spot behind rear passenger tire. Vacuumed down the system. System seams to be sealed it held -30 for a few hours. I have the compressor jumper d by running a wire from battery to pin on the a/c relay in the fuse box. Compressor spins but when I try to add r134 it will not accept it. Any help would be wonderful. Thanks in advance.

 

[j91z28d1]

if it is under vacuum. it should take atleast a can or so before even needing jumped.

do you have gauge?

 

[AnimalMother]

Yes I have a gauge set.

 

[AnimalMother]

However I did not try to add r134 while the system was under vacuum. I will go out and pull vacuum on system and try to add r134 while system has negative pressure. Dose an ambient temperature 60 have any affects on system taking on refrigerant?

 

[j91z28d1]

what does it do when you open the valve to fill? like you have a vacuum showing on the low pressure side dial, and then open the knob to let the can in, the needle should show pressure form the can when you open the valve?

dumb question, cause it doesn't sound like this isn't the first time you've done ac work, but did you puncture the can?

 

[j91z28d1]

However I did not try to add r134 while the system was under vacuum. I will go out and pull vacuum on system and try to add r134 while system has negative pressure. Dose an ambient temperature 60 have any affects on system taking on refrigerant?

OK, maybe not.

so you need to vacuum the system down by putting the yellow hose on the pump and opening both knobs. run it for a good 30mins or more. it's been open a long time with that leak, hopefully you changed the accumulator as well, but anyways. run the vac pump a long time. mini 30 min. close the valves on the gauge set, disconnect the yellow from the pump, installed the can. open the low side valve (blue) and let the can in.. it should take a can or almost all of it. you can warm the cans in hot water if you want to put it all in that way, (some do) or start the engine and let it suck the rest in. be careful when you switch cans, the goal is to allow zero air into he system. any air is bad on everything.

to the point most people close the low side valve to change cans, hook the new can up, crack the yellow how fitting at the gauge set to let some freon out to purge any air allowed into the hose when changing before opening the valve for the next can. it's not fully needed if you don't understand my gibberish haha. but you get the idea. zero air in the system

 

[j91z28d1]

oh and cans are usually 12oz. 16oz in a lbs, the listing is usually in lbs.

 

[AnimalMother]

Got it. Probably best the cans did not go in because if I did it without reading this no doubt there would be air in the system. I have 4 cans 12oz each. I read the Tahoe's with rear a/c take 48oz for a complete charge from empty. Am I filling according to weight or pressure or both? I did not replace the accumulator. There are a bunch of Tahoe's at the local upullit yard. But I bet you are going to say that accumulator is a part that must be purchased new.

 

[AnimalMother]

One last thing. I am getting conflicting info on adding PAG 46 oil. Given I did not replace any major components ie. Compressor. Do I add PAG or is it still in there even after pulling a vacuum?

 

[swathdiver]

One last thing. I am getting conflicting info on adding PAG 46 oil. Given I did not replace any major components ie. Compressor. Do I add PAG or is it still in there even after pulling a vacuum?

No oil necessary in your case.

Take off the jumper run the AC at its coldest temperature setting and highest fan setting and then add the refrigerant. Your Tahoe's R134A capacity is 2.5 pounds. 3 Pounds is the capacity of the Suburbans.

Use the charts that came with your manifold to make sure you are hooked up correctly and introducing the refrigerant to the truck according to the instructions.