TX Tahoe Z71

iTrader: (28)

All of a sudden while driving yesterday, I noticed my compressor cycling on and off every few seconds and my ac getting progressively warmer. Within about 15 minutes, it was blowing warm air. I put AC gauges on it today (thanks AutoZone loaner tool program).

The low side would slowly drop to about 70, then spike to 150+ when the compressor cycled off for a few seconds, then slowly retreat back to 70-80 when it kicked back on. The high side stayed pretty static at about 170. The air coming from the vents was always warm, whether or not the compressor was on. Outside temps are 95* with about 70% humidity.

When the compressor would kick on, the engine would bog for a second or two before returning to idle, much more so than normal.

Orifice tube failure, busted compressor, something else?

Any advice or tips are greatly appreciated.

Here are the gauges, with the low side creeping back to 70

TX Tahoe Z71

iTrader: (28)

Also, the metal AC lines were hot the whole time, they was no cooling going on.

Suburbazine

Most likely a dead compressor. If you're seeing the low side fall but the high side steady, usually means a clogged discharge line, which usually means destroyed compressor.

TX Tahoe Z71

iTrader: (28)

How can I test the compressor? The clutch is engaging and when it does, the low side pressure drops, which I assume means it's creating a vacuum on the low side.

TX Tahoe Z71

iTrader: (28)

Planning on flushing the lines, then replacing the dryer and orifice tube. Should I replace the condenser as well?

01ssreda4

iTrader: (87)

Yes. They are cheap.

TX Tahoe Z71

iTrader: (28)

Probably a good idea, thanks

Suburbazine

Yep, good idea. It's also the easiest way to find out if the compressor has shot metal shavings down the pipe.

TX Tahoe Z71

iTrader: (28)

If I have not turned on the rear AC since my compressor (likely) bit the dust, will I still need to replace the rear expansion valve? Meaning, does the on/off switch for the rear AC control if refrigerant is circulated to the rear ac lines?

TX Tahoe Z71

iTrader: (28)

Just thought about this. I'd imagine the refrigerant is always circulating and the rear control just turns on and off the blower motor. So I guess I'm replacing the rear expansion valve. Yay