A/C recharge 99 yukon

[RED TAHOE LS]

1. The receiver-drier / Accumulator must be changed each time a system is empty regardless of the reason for loss of refrigerant. Once the system is open to the atmosphere more than a short period of time, the desiccant can become “full” of moisture, which can lead to corrosion. This can cause the expansion valve or orifice tube to freeze, which can block refrigerant flow in the system.
2. It should also be changed every three years, because the desiccant pellets will break down and clog the expansion valve. This will in turn cause the system to become inoperable and May damage the compressor.
3. In fact, if any component fails or is replaced for any reason, the receiver-drier / Accumulator must also be replaced to prevent corrosion and moisture in the system.

Ron, it's better explained here than I could relate to you, it's from an AC manual. Good luck,
David G...........

 

[skychair]

Got together with my friend (he had the gauge set and pump) removed the AC Delco ( year old) and replace it with a new Delphi, hoping that the noise I was experiencing in the Yukon while driving was from the compressor .......it was not.

We made the swap with no real problems, but when we drained the oil from the old compressor I was surprised to get only 1 oz from it. When we drained the new compressor we got 6 oz, this is quite a disparity.
So time to figure what to do.
This system requires 11oz of oil (I used PAG 150)
I figured 5.5oz remained in the system for the rear air,accumulator, evaporator, condenser, minus 2.5/3 oz lost that was suspended in the R134a when removed .
So 5 oz went in to the compressor closely approximating the 11 oz needed.
Buttoned every thing up, rotated the compressor by hand to get oil to the compressor parts (about 15 rotations).
Vacuumed it down, needle read 30, vacuumed for 30 or so minutes, held 30 for 1/2 hour.
Charged up with 5-12 oz cans, plus 3oz from a 6th can.
It was an hours ride back home and it got cold, guess I have to either live with the noise, or start a new search.
I was able to return the old compressor (Amazon), so my only cost was the R134A.
I'm probably going to buy a set of gauges and a pump next time I need to do this.
Wish to thank all who responded to questions I had concerning A/C re-charging, appreciate it.
Ron

 

[largewon62]

Just a thought. If you are getting temps of 38-40 from your center vent, your system is working quite well. If the temp drop much more, the evaporator will freeze up on you.