1990 Chevy 1500 - Dead A/C?

[Mopar1973Man]

This thread is for Flman more so.. But all help is welcomed! But I just had a customer show up with a cycling A/C compressor showing the signs of low freon but got my manifold hook up and... (Here's where its gets weird!) The low side is cycling at 100-120 PSI rising at the same time with the high side at 100-120 PSI. So as the clutch locks it rises together to 120 and cuts out. I just want to verify I'm looking at a dead compressor.

[KOYOTE]

it looks to me that there is no resistance to flow, i try to keep mine at 35 low and about 250 high, my money is on a orfice tube that is blowed out not just a failed compressor

[Mopar1973Man]

That's the odd part... Typically you would see the low side go down to 35 PSI or so and the high side rise up to the 250 mark or so... But to get both jumping up and down together its like the valves in the compressor is blowing and sucking in both sides...

[KOYOTE]

well in my mind if the valves are jamed its probably metal contamination which will have collected at the orfice tube which is right in the line by the condensor on a 1500, real easy to remove,inspect, clean and reinstall.

[Mopar1973Man]

Well I can give this info too... When I pull the manifold and discharged the high side high on the manifold the oil was clean and only had a slight tint of green too it (Dye pack).

[Terry C]

Ever figure this one out?

[Mopar1973Man]

Yeah we did... It came down to pulling the compressor and looking and it had "Black Death" the guts of the compressor where starting to fail. So we called around and ask for the A/C flush... What we found out is NAPA seel the flush but you'd need about $300 worth to clean the system properly. So we ask what it would cost to replace the entire system which turn out to be close to $360 bucks so we ask the owner what he wanted to do... Put a replacement pulley in and omit the A/C completely... $35 bucks... (Smart thinking!)

[Terry C]

Good choice........