how may onces with rear air?

sticker is gone...

any burb guys out there?.....

REFRIGERANT-134A

Pickup Models 0.91 kg (2.0 lb.) Crew Cab Suburban and Utility Models Front A/C only 1.02 kg (2.25 lb) Suburban with Rear Air Conditioning 1.81 kg (4.0 lb)

Overcharging a system may allow liquid Refrigerant-134a to get into the compressor, causing compressor noise and damage. Undercharging will cause insufficient cooling.

While we're on the subject of ACs. What causes mine to blow nice cold air for a while and then gradually warmer. If I shut it off for a bit it will go through the same cycle.
Is this from too little refrigerant? Or likely something else?

Does the Crew cab and suburban and utility truck have a different compressor?
Or can I squeeze that xtra .25 in my system?

Louis

REFRIGERANT-134A

Pickup Models 0.91 kg (2.0 lb.) Crew Cab Suburban and Utility Models Front A/C only 1.02 kg (2.25 lb) Suburban with Rear Air Conditioning 1.81 kg (4.0 lb)
Overcharging a system may allow liquid Refrigerant-134a to get into the compressor, causing compressor noise and damage. Undercharging will cause insufficient cooling.

thanks...i thought it was around 4 pounds

HamOP it's probly freezin' up....does your compressor cycle?

REFRIGERANT-134A

Pickup Models 0.91 kg (2.0 lb.) Crew Cab Suburban and Utility Models Front A/C only 1.02 kg (2.25 lb) Suburban with Rear Air Conditioning 1.81 kg (4.0 lb)

Overcharging a system may allow liquid Refrigerant-134a to get into the compressor, causing compressor noise and damage. Undercharging will cause insufficient cooling.
Interesting...My Mom's 99 3500 Express is 3.5 Lbs with the rear air. Burbs must have a bigger rear air unit, unless when they switched compressors in 96, the are more efficient??

HamOP it's probly freezin' up....does your compressor cycle?

I honestly don't know... I'll try to find out when it gets hot out again and ask again then.
Thanks!

While we're on the subject of ACs. What causes mine to blow nice cold air for a while and then gradually warmer. If I shut it off for a bit it will go through the same cycle.
Is this from too little refrigerant? Or likely something else?


Sounds like it is freezing up. It could be a variety of things from your compressor constantly running to something clogging up air flow.

REFRIGERANT-134A

Pickup Models 0.91 kg (2.0 lb.) Crew Cab Suburban and Utility Models Front A/C only 1.02 kg (2.25 lb) Suburban with Rear Air Conditioning 1.81 kg (4.0 lb)

Overcharging a system may allow liquid Refrigerant-134a to get into the compressor, causing compressor noise and damage. Undercharging will cause insufficient cooling.
This is true for the 96+ with the aluminum housing compresser. 95 SUBURBAN should be 2.25 pounds IIRC, I'll check my 95 SUB tommorrow for you.

It could be a variety of things from your compressor constantly running to something clogging up air flow.
2 questions then.
Are you talking about the air flow in the cab? Seems fine.
I've been reading and see that there's a compressor cycle switch. Could this be bad?
OK - 3 ?s - Can this be changed without opening the system?

I recently discovered while chasing a leak on my 97 that if the freon level is too low, the PCM (no, not the low pressure switch) will disable the compressor. I had jumpered the low pressure switch on the drier in order to add freon (or R134a if you want to get technical). The compressor was cycling on and off due to pressure read on the cycling switch. After a few minutes the compressor turned off and stayed off until I shut the engine off and restarted. I had to do this a couple of times in order to complete the charge. I also noticed prior to finding the leak the A/C would cool just fine for a few minutes before the compressor would shut down completely when the freon was low. Turning off the engine and restarting would make it cool fine for another few minutes. You're probably just low on freon.

BTW The leak turned out to be the orings where the compressor case is put together.