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Discussion Starter #1
Hi all,
I'm slowly trying to identify my wife's A/C issue in her saab. It' blows cool air, with the A/C compressor running, not cold air. Last summer, I replaced the clutch plate on the compressor because the rivets had failed. Clutch engages when A/C is called for, and dissengages when it's not.
I bought a set of gauges, but I can only find the low side port, near the PS reservoir. I assumed the High Side port would be easy to locate, but I'm lost. I've looked everywhere a flashlight can shine.
I saw an older 9-5 in a search which had both the high and low side ports behind the grill, but my wife's car is the facelift with the one piece bumper.
I suspect there's no easy way to find the port other than pulling the bumper cover off, right? Or is it hidden underneath a headlight? Which also requires bumper cover removal.

My low pressure side read 40ish psi on a 70 degree day with Compressor running and air blowing slightly colder than ambient. My suspicion is the compressor has failed/is failing causing a high low-side pressure, but could it instead be the expansion valve? I'm guessing you're all waiting for the actual High and low pressure readings with engine off and on.
 

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Discussion Starter #4
It's truly a sad day. I've now had independant confirmation that I'm blind. It's right there, staring up at me. Thanks dho. I'll update on my pressures
 

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Discussion Starter #6
How ironic. I just watched a video where this poster was linked to. Engine off pressures were 75 low side and 75 high side. Then right after start up and A/C on, it was 35 and 130. I saw and heard the compressor kick on and then off and back on and got a level reading at 34 and 110.
The Nissens chart shows Scenario 5: Normal or too low LP side and HP side too low as: low refrigerant, Expansion valve failure for Variable Displacement Compressor(is that ours?), or System Stoppage between dryer and evap. And replace dryer
Scenario #1 is possible with a Too High LP side and a too low HP side. Possible cause is clutch-hub slips on the pulley (i replaced the clutch due to broken rivets on the old one, maybe I didn't gap it correctly).
How do I tell if the system is correctly charged without first evacuating it and measuring what goes in or out? Anyone familiar with what equalized pressures should be at around 78 degrees ambient? Do these pressures indicate anything to you?

Thanks
 

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You can't tell about the amount of charge without evacuation and recharge. I would get a couple cans or r134-a and add slowing and see if your high side pressure increases. Use the chart in that Nissen PDF for ambient temp range for approximate pressures. I think if you ball park 40 low side/200 high side will get you close with ambient temp in the high 70's. You'll have quite a few opinions here about the correct way is to evacuate the system, pull vacuum then measure correct amount to charge the system. It's technically correct but you might achieve cold air by ball parking it and r134-a is pretty cheap at Walmart. Make sure you get the adapter for the newer cans of you are planning in charging yourself, do not buy any of the solutions that include sealing liquid it it.
 

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Discussion Starter #8
So barely driving the car during quarantine. But I checked and added freon to the system and it seemed to work well. I may have been gunshy about going too high, so it may require more. I assume if there's any leaks, it'll leak whether it's at static pressures, not just working pressures. I drove it maybe 20 miles and no problems.

The other day, it's like 90 degrees outside. I load up the car for a trip, start it, and the A/C is working away, tying to take the super hot heat out of the interior (90ish degree day, direct sun). My wife goes to pull out of parallel parking space and boing!!! The serpentine belt pops off. I look and it's intact, but it's a couple weeks till I can get back to it.

Once I do, i manually spin the center of the compressor, and it turns. Water pump, and power steering, all pulley turn without any glaring issues. I did recently replace the power steering pump with a Reman from AC delco, so it's possible I have a misaligned power steering pulley, or bad pump, but remember last summer I replaced the A/C clutch plate due to failed rivets.

I assume the failed rivets occured for a reason. Would this info make you believe that the compressor is occasionally seizing? The first time the rivets failed like they are designed to, and the second time the belt popped? or would you look elsewhere?

How would someone test the compressor for intermittent seizing?
 
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