1991 Chevy k1500.

The A/C compressor started making noise this weekend. Grinding noise when the engine is turned on, then a kind of loud humming/whistling while running.

What's the procedure for repairing or replacing this compressor?

thanks!

 

I would change it before it grenades inside and you have to REALLY flush the system. As it is right now you can get away with replacing the compressor, accumulator, and orfice tube. I would replace any o-rings that you have to open the fittings on also. I always use a little denatured alcohol to flush the condenser too.

 

Okay I don't have any experience replacing those parts. Is it something I can do myself? If so can you point me to a link that has instructions or give me a step-by-step?

Thanks!

 

I guess it depends on your mechanical ability. You will be working with a high pressure system and will need the proper tools. You should have the system evacuated by a mechanic. You could save some money by just having a mechanic evacuate and charge the system, but a decent shop shouldn't charge much to install everything anyway. If you feel your up for the task I can walk you through it.

 

I appreciate the offer, but I think I'll pay a mechanic or a shop to do this, so I should tell them:

1. evacuate/flush the system
2. replace the compressor, accumulator, orifice tube and o-rings
3. charge the system

 

Yep, good luck. Let us know how it works out.

 

Okay I bought the parts and had my mechanic install them since I don't have the proper equipment to do it myself.

It's blowing cold air now and working great.

Question: under normal circumstances how often should the compressor cycle on/off?

 

That depends on how much freon is in the system, and how fast the condensor cools off.

 

Well, assuming it's property topped off and it's in the 90s today. (dry heat)

 

Lets see if you pop the hood and let it idle with the ac on high, get a water hose and spray the front of the condensor and see if the clutch kicks on and off but not real fast. It should cycle like every 8 seconds but thats a rough estimate cuz it depends on how fast the condensor cools off.