How much refrigerant 98 Tahoe

[Dariusz Salomon]

Hi guys-I recently fixed the whole system-front and back(separate controls for the back) and I put 1200g of r134 in it. On the machine it show propper pressure however it's a lil slow on hot days. So my question is-is 1800g (64 ounces)an amount I should put in the system? If I put less would that be a cause of being slow? Or is there anything else I could do to improve it(I havent cleaned heather matrix ever? The sysyem is sealed-no leaks-checked it with UV light and yes-I have dye in the system.

 

[L31MaxExpress]

For dual air, 64oz or 4 lbs of R134a and 11 oz of Pag 150 is correct for a GM a/c compressor. Many replacement compressors are Pag 46 though. For whatever reason, when the system is low the front will blow coolish air and the back will be ice cold.

 

[HotWheelsBurban]

For dual air, 64oz or 4 lbs of R134a and 11 oz of Pag 150 is correct for a GM a/c compressor. Many replacement compressors are Pag 46 though. For whatever reason, when the system is low the front will blow coolish air and the back will be ice cold.

Probably because the rear evaporator core isn't having to deal with the engine compartment heat. I was told back in the 80s at a GM training center AC service course that a car air conditioner is powerful enough to cool a 3 bedroom house, just to compensate for the engine compartment heat. Probably even worse now with smaller engine compartments....

 

[L31MaxExpress]

Probably because the rear evaporator core isn't having to deal with the engine compartment heat. I was told back in the 80s at a GM training center AC service course that a car air conditioner is powerful enough to cool a 3 bedroom house, just to compensate for the engine compartment heat. Probably even worse now with smaller engine compartments....

Could also be because the rear usually has expansion valve and the front has an orifice tube.

I think the old GM A6 compressor was rated around 42,000 btu.

A house also does not typically have the sun load of all the glass nor is it asked to cool down from 140°F or more in a short period of time.

 

[HotWheelsBurban]

Good points! There was a GM training center and zone office down the street from where we had our parts store for several years. So we took courses there, when there were Delco service classes. Better to be extra informed about the stuff you're selling, and get some of the garage mechanics to take them too.