High Low Side, Low High Side

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High Low Side, Low High Side

Postby paulcalif » Tue Aug 29, 2017 6:55 pm

Just purchased an 2000 Durango. The price was right, but it needs work.
The AC doesn't blow cold.
I checked the refrigerant with one of those cans with a gauge attached (my gauges are 100 miles away). It was reading in the red zone = high pressure (on the low side). I let some refrigerant out, and the pressure lowered some but still way too high.
I rented a set of gauges and the pressures read as follows.
85 on the low side, 95 on the high side.
I tried to add a little refrigerant (134a) but at idle it wouldn't take any. At high rev, the low side pressure drops and the pump gets REAL noisy. I added some refrigerant to see what would happen. It certainly didn't drop the pressure, and I think it went up some more.

The compressor is fairly noisy at idle making, like playing cards on the spokes of a bicycle.
Much worse when I rev it up.
I figure the compressor is bad.
This car has an expansion valve in the engine compartment on the firewall. Not easy to change, but doable.
The car isn't worth taking to an AC mechanic, but I don't mind putting a compressor and or expansion valve in it.
Oh, and it also has rear air, so two expansion valves and two evaporators.
Luckily, I have other vehicles as we are in the middle of a heat wave. Temp yesterday was 113.

Anything else I can do to be certain that it's the compressor?
From what I've read, the psi readings tell me it's either the compressor or the expansion valve, and the noisy compressor confirms that it's the compressor.

I rented a vacuum pump too.
If I do get the new compressor, of course I'll get a new receiver/drier too.
And oil if it doesn't come full.

Will greatly appreciate any and all comments.

Thanks in advance.

On a side note, the upper control arm bushing is GONE, not just warn out, but actually GONE - the nut that held it on is gone too! (Never seen that before.

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