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2007 AWD 3SS
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8,588 Posts
Discussion Starter · #1 ·
So, the AC isn't cooling so good. Figured it's 5years old and just needs a charge. I added a can of freon, didn't help, actually made it worse. I hooked up the gauges and its not cycling on low side pressure, its cutting off from hi side pressure when over 2000 RPM. The pressure jumps up to 450 psi and shuts down the compressor.

I figure the orifice is clogged, what are the chances the compressor is bad?
 

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TrailblazerSS
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603 Posts
Sounds like the comp is ok with pressures like that. Id go with the orifice tube and I would also change the receiver/ dryer. Put it on a vacuum for at least a hour the longer the better and I would def put some dye in it

Good luck

Sal
 

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Premium Member
2007 AWD 3SS
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8,588 Posts
Discussion Starter · #3 ·
I took the easy way out, I released freon until the hi side pressure stayed below 400 PSI at 2500 RPM. Now it actually works when I am cruising down the highway and gets freaking cold. Amusingly, the low side pressure never really dropped much, lowest it goes is like 40PSI now, so it's not so low as to freeze the evap core over.

I figure the problem will get worse over time, as the accumulator must be releasing trash into the orifice tube. I'll wait to change the accumulator and orifice when it's convenient for me and hopefully before the compressor sucks any trash in.
 

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TT AWD TBSS Jeep
TT AWD SS Pwrd Jeep
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Agreed on the orifice tube, but continue to let out the freon til you see 35psi at idle. Idealy you would want to see around 250 on the high side. 400 is still high, unless its like 105 out, even then 350 would be a better pressure. My gauges on a mid 80's degree day are 35 and 250, which nets me at idle 39 degrees out the vents, and going down the road it come out at 36-37 degrees with the fan switch on 3 and 4 respectfuly. In my opinion you still have too much freon in there.
 

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2007 AWD 3SS
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8,588 Posts
Discussion Starter · #6 ·
Agreed on the orifice tube, but continue to let out the freon til you see 35psi at idle. Idealy you would want to see around 250 on the high side. 400 is still high, unless its like 105 out, even then 350 would be a better pressure. My gauges on a mid 80's degree day are 35 and 250, which nets me at idle 39 degrees out the vents, and going down the road it come out at 36-37 degrees with the fan switch on 3 and 4 respectfuly. In my opinion you still have too much freon in there.
Understood, but take into account the average day here has been between 95-100º. I may let a little more out.
 
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