Automotive Air Conditioning Information Forum (Archives)

dave76 on Tue August 03, 2010 7:52 PM

Year: 1999
Make: Chevy
Model: Tahoe
Engine Size: 350
Refrigerant Type: R134a
Ambient Temp: 88°F
Country of Origin: United States

Looking for the proper charge amount, because the accumulater sez 2lbs 12oz for Tahoe, Suburban 3lbs 8oz. After reading the threads here it seems the proper charge is 64oz with rear which I have.

GM Tech on Tue August 03, 2010 8:15 PM

my chart says 64 oz

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The number one A/C diagnostic tool there is- is to know how much refrigerant is in the system- this can only be done by recovering and weighing the refrigerant!!
Just a thought.... 65% of A/C failures in my 3200 car diagnostic database (GM vehicles) are due to loss of refrigerant due to a leak......

dave76 on Tue August 03, 2010 9:39 PM

Alright 7 cans of 134a, then.

Anyway the A/C works fine, just that I see oil leaks out of the low side cap on the compressor and upon removal of the cap you get that little puff of gas. I put my gauges on and got at 2000 RPM about 30 PSI low, and 230 PSI high @ 88°F ambiant temp, about 43-45°F register temps, and 50-53°F at idle. My plan is to reclaim the refrigerant, replace the schrader valves, pull a vacuum for and hour and recharge it. Question, should I replace the orfice tube while doing this?? I also insulated the suction line with extra insulation including the muffler. This truck still has the stock HT6 compressor, but it dosn't seem to be leaking.

dave76 on Wed August 04, 2010 5:46 PM

Bump

dave76 on Thu August 05, 2010 5:04 PM

dave76 on Thu August 05, 2010 5:13 PM

Well I recovered all the charge, replaced the low side schrader, looks like highside valve will need replacing, will do next year. Pulled the OT it was a greyish color, woundering if the compressor is on it way out? Next year I would like to rebuild the whole system.

Anyway I charged the sytem with 5 cans and 4oz out of the 6th, it's running awsome now, I did notice the suction line from the rear evap all the way to the front sweats like hell, would probably be a good idea to insulate it??