AC Compressor issue

[glendayle]

Looking for some guidance. AC was ice cold and working up to about 3 weeks ago. All of the sudden the AC wouldn't cool. In actuality, it does slightly cool the air, but not a lot. At the same time, I noticed a clicking sound when the AC is on. Turns out the compressor is making a clicking noise.

I know that low refridgerant levels can cause the compressor clutch to not engage and subsequently not cool.

I've also been told that the clutch bearing can go bad which can also cause the the compressor to not cool the air despite having no issues with the refridgerant levels.

Can anyone with previous experience diagnose this issue? Video attached below. Clicking sound is when I press the AC button on, and it stops clicking when I turn the AC off(but still have the blower going).

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Thanks in advance.

 

[Justin S]

Over the interwebs, my guess is the clutch on the compressor isn't holding while engaged anymore, like a transmission clutch, its slipping under load. If its the noise in the video though, regardless, needs a compressor.

 

[glendayle]

Over the interwebs, my guess is the clutch on the compressor isn't holding while engaged anymore, like a transmission clutch, its slipping under load. If its the noise in the video though, regardless, needs a compressor.

Replacing the clutch and/or clutch bearing is pretty easy and can be done without opening up the system. Is it not engaging because of low refrigerant though? or a bad clutch bearing?

 

[Fuzzy]

Seconded on clutch, if it was low on pressure the switch on the compressor wouldn't allow it to engage the clutch at all.

 

[glendayle]

OK. Sounds good guys. I'll look into replacing the clutch. If anyone else has any input or experience, please post. I'll let you know what happens when I replace the clutch.

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[Fuzzy]

Just for ***** and gigs I checked AD for you and it appears that if there is a massive discharge on the low side the compressor could still cycle, so what I said may not be 100% true.

Additional compressor protection results from the operating characteristics of the low-side pressure cycling system. If a massive discharge occurs in the low side of the system, or the orifice tube becomes plugged, low-side pressures could be insufficient to close the contacts of the pressure switch. In the event of a low charge, insufficient cooling accompanied by rapid compressor clutch cycling will be noticed at high outside (ambient) air temperatures

Simplest way I could tell you to check this would be to get one of those cheap AC Pro Kits (You don't have to use the Refrigerant, just need the gauge) or rent some manifold gauges and check the low pressure side's pressure.

 

[SAATR]

A set of real (albeit cheap) gauges can be had from Amazon for little more than the cost of the ACPro kit. I would check system pressures and have it evacuated with an AC machine to check the charge level. The noise that the compressor is making in your video is typical of older HT6 compressors, though without hearing it in person I can't tell if it is too loud. Too loud would mean the internals are on their way out, which would cause poor pressure on the high side and subsequent poor cooling. I would gather some more data, like pressures and actual charge level, before you throw parts at it.

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[someotherguy]

Sure sounds like a grenaded compressor, to me...

Richard

 

[ram1220]

That sound in the video is exactly how mine sounded on my 90 Sierra when the compressor was dying.

 

[glendayle]

Just for ***** and gigs I checked AD for you and it appears that if there is a massive discharge on the low side the compressor could still cycle, so what I said may not be 100% true.



Simplest way I could tell you to check this would be to get one of those cheap AC Pro Kits (You don't have to use the Refrigerant, just need the gauge) or rent some manifold gauges and check the low pressure side's pressure.

That sound in the video is exactly how mine sounded on my 90 Sierra when the compressor was dying.

Did you just replace the compressor? Or did you look into the issue? A lot of shops just replace the compressor, but from what I've read, usually its the bearing/clutch/or that other little electronic part all of which are relatively inexpensive and can be replaced without opening the system.