A/C Help - 1989 GMC Sierra 1500

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Rtlane

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ok I added more refrigerant. It doesn’t cycle much now. Maybe once every minute or 2. It’s 73 degrees here right now. The only issue i see now is a little bit of ice on the lines at the accumulator. Wondering if i vacuumed long enough or maybe where the cap was broke, it wasnt vacuuming correctly.
 

PlayingWithTBI

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PlayingWithTBI, since you used the same condenser, how much refrigerant did you refill your system with?
I charged it until it stopped cycling @100* ambient. My pressures were still lower than this chart shows. Be careful, if you charge it too much, when hot you'll start building too high of pressures and you'll put undue strain on the compressor clutch. Play it by ear for now - if it blows cold, you're good. :waytogo: Wait until it gets hot to see how it performs.

 

Rtlane

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Thank you everyone! I’m happy with it. We will see how it goes moving forward. I picked up an ac thermometer and im getting 42 at idle. Im happy with that. I gave to put my grille back on before I drive to check the temp.
 

kenh

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The interweb will have a chart that will convert pressure to temperature. Look at the low side pressure and convert that to temp. I personally would like to see evap temps above freezing to avoid icing of the evaporator. That restricts airflow and cooling of the cab.

My evap temps are a little low and I suspect I have a tad too much refrigerant in the system. I just remembered I have 2 1/4 pounds of 134 in my truck. I'll go back and edit my previous post to the correct amount.

Ken
 
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