A/C testing

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Marbor

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So purchased 01 Yukon xl in November when it was freezing and turned ac on when purchasing but it was to cold to tell. Any how springs in and summer heat is approaching soon I figure I can get ahead of it now then later.
So here goes I noticed the compressor was ticking on but only warm air was flowing from the vents. Went under watching the compressor and noticed the pully was bad and not putting enough pressure on the compressor to turn the ac pully. I swapped pully and belt now compressor is turning and I can feel the cooler air in the vents.
Question is the air doesn’t feel ice cold but it’s cool I believe in the sweltering heat it will not suffice. Any recommendations on how to check the pressure myself Or is it best to take it in and pay the price? I was looking at those cans they sell at Auto Z but don’t know if they really work any advise.
 

Doubeleive

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you can add some yourself but if you do that pay the little bit extra for the one with the DYE in it so you can find where it may be leaking from later on down the road.
 

dnt1010

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Always best to read both low and high side pressures when recharging. You can buy set of auto R134A gauges at a good price if you search around a little bit. Should be under 50 dollars. When ready to do this make sure the outside ambient temp is 80f or above. Windows down AC set to Max cool / blower fan set on highest setting / all vents open and engine at 1500 RPM, that will be your "base pressure" to work off of. Average reading would be around 35 or so on low side and 220 to 300 on high side dependent upon outside ambient/airflow through condenser. Do not panic if high pressure is low and you need to add a little refrigerant. At almost 20 years old that is normal, ALL auto ac systems utilize flexible hoses that are partially permeable (refrigerant molecules leak through the hose material) granted the leak rate is tiny but ALL auto ac systems will need recharging after several years. Nature of the beast. If you can post your pressures it would be interesting to armchair quarterback this project......
 
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Marbor

Marbor

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Always best to read both low and high side pressures when recharging. You can buy set of auto R134A gauges at a good price if you search around a little bit. Should be under 50 dollars. When ready to do this make sure the outside ambient temp is 80f or above. Windows down AC set to Max cool / blower fan set on highest setting / all vents open and engine at 1500 RPM, that will be your "base pressure" to work off of. Average reading would be around 35 or so on low side and 220 to 300 on high side dependent upon outside ambient/airflow through condenser. Do not panic if high pressure is low and you need to add a little refrigerant. At almost 20 years old that is normal, ALL auto ac systems utilize flexible hoses that are partially permeable (refrigerant molecules leak through the hose material) granted the leak rate is tiny but ALL auto ac systems will need recharging after several years. Nature of the beast. If you can post your pressures it would be interesting to armchair quarterback this project......

Thanks for the response I will be looking for a set of gauges in the mean time.
Today was a perfect day 75 Deg and pretty wore in the truck when I left work, so I blasted the A/C with windows closed and sure got pretty cold after about 15 mins of driving so I think I’m good to go for now but still wanna check the system to insure it’s at max operational.
 

PG01

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Thanks for the response I will be looking for a set of gauges in the mean time.
Today was a perfect day 75 Deg and pretty wore in the truck when I left work, so I blasted the A/C with windows closed and sure got pretty cold after about 15 mins of driving so I think I’m good to go for now but still wanna check the system to insure it’s at max operational.
At idle tho, really should put the correct charge in there, can burn up compressor without
 
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