Automotive Air Conditioning Information Forum

Hi everyone, new member here.
I thought I submitted a new topic yesterday but it disappeared so I'll try again.
2016 cadillac ats
Before I go and purchase a new ac compressor, I'd like some way of finding out if the compressor itself is bad
Here is the reason...
I bought the car used a few months ago and the ac worked, then it stopped. After some amateur testing. I recently noticed the outer compressor clutch piece broke off (it was engaging previously but only hot air came out).
I removed the outer broken clutch piece so that the compressor is basically a pulley.
When I turn the center shaft by hand it is tough, it turns about a 1/4, the gets tight, I hear/feel a click and then it turns...over and over again.
What does a good compressor feel like? Is what I'm noticing normal?
I'd rather just buy a new clutch but I don't want to buy a clutch and then realize I need a compressor also.
Thanks

NY Caddy wrote: ↑Thu Nov 09, 2023 6:53 am What does a good compressor feel like?

I'm not a professional, have installed about a dozen brand-new compressors is different vehicles. The center drive plate should turn with a wrench with some resistance but not forcing it.

NY Caddy wrote: ↑Thu Nov 09, 2023 6:53 am I'd rather just buy a new clutch but I don't want to buy a clutch and then realize I need a compressor also.

Contact Tim (the sponsor here) at ACkits.com

You may find that an AC clutch-only may not be available, or that its cost would be similar to a brand-new compressor WITH a clutch.

Also, on many vehicles, the AC clutch cannot be swapped without removing the compressor from the engine due to clearance issues.

I'm thinking maybe the compressor went bad and then caused the clutch to break off. ?
I found a clutch kit online and it's over $100. I think a new compressor is around $400. Then I'd have to have an ac shop refill it.
It's very tight access but if I remive a few bolts it might drop down a bit to work on.
Here is a pic of what's left of the clutch. The piece I'm grabbing and turning is on the compressor, the center ring looking thing. Not what is in my hand

"When I turn the center shaft by hand it is tough, it turns about a 1/4, the gets tight, I hear/feel a click and then it turns...over and over again."
Bad news.
"I'm thinking maybe the compressor went bad and then caused the clutch to break off. " Correct.

How many miles out of curiosity. Very few compressors will give you much more than 100K.

Also, since the comp has grenaded, there is now shrapnel downstream waiting to clog up your system. The line from the comp to the condenser must be changed out, and the condenser must be changed. A modern condenser cannot be flushed. If you have a TXV, that will need replacing, as well as the receiver dryer and the associated lines from the condenser to the evap

Not a job for the faint of heart

Thanks.
That's what I was afraid of hearing but figured what actually happened.
The car has 70k miles and seems to be in nice condition.
I saw videos of people flushing ac lines with carb cleaner..can I save some of the lines by doing that?

As already said, indications are that the compressor has failed internally, as well as the clutch. That means you'll have to replace not only the compressor assembly but also the condenser, the receiver/dryer or accumulator, and possibly the metering device.

The lines can be flushed with the proper solvent and thoroughly dried as long as none of them has a muffler (an in-line can-like device). Lines with mufflers must be replaced.

Does this car take R-134a or R-1234yf? The latter will be considerably more expensive to deal with.

"I saw videos of people flushing ac lines with carb cleaner..can I save some of the lines by doing that?"
This yields very unpredictable results.
My good friend John, above, probably has more faith in line flushing than we do, we just replace them. I do not think carb cleaner is a good choice. Tim, the board sponsor, has good prices on every imaginable mobile AC part and has flush available at ackits.com. Whatever you do, do NOT use any type of water based product, you will destroy the entire system.
There is pro flushing equipment out there (Hecat) but rather pricey for a one-off situation.
Best to protect your investment of the comp and condenser by getting new lines (the hoses are minimal dollars). If you flush and don't get all the fine bits of metal, you will soon trash out your precious new compressor

Thanks JohnHere and TbirdTbird
I won't be around the car for a month or so and I'm not sure what refrigerant it takes.
I will look for a service manual diagram to see all the parts involved. I don't know most of the part names, I have an idea though. I will look for Tim's info.and what he has.
So far, a new condenser was around $80 at a quick look on the web.

Check for an under-hood decal that will specify what type of refrigerant and oil it takes (unless the decal is gone).

For a lasting repair, I recommend purchasing a new compressor, which usually comes with a new clutch. Tim will have or can get everything you need at the best prices.

send Tim an email with the make model year of car and ask him for everything from the firewall forward. He will respond, he is very accommodating.
Then you can compare your prices. But he has very good quality prices at very reasonable prices.
This type of repair , while aggravating, and costly, is ever so common when a compressor lets go. It is a way of life. The guy who sold you the car knew the AC was shot.
Few car owners on here can actually make the repairs themselves. They come here for diagnostic help usually. Accomplishing the repairs can be tricky, especially for the first timer. We have all been there and mastered a bag of tricks. To get a good install, look around for a MACS certified shop. John is a MACS certified technician and I must add a very good one. I thought I knew a lot about mobile AC when I first joined the board, but I have learned a lot from the rest of the consultants including John, and of course Tim.
MACS stands for mobile air climate systems, and is the only source of MVAC certification in this country.
Try HARD NOT to go to a brake or muffler shop with a sign, "We do AC"....because honestly they do not know what they are doing. AC is very specialized
Good luck. Don't be afraid to ask questions. We are here to help.
Perhaps you can pull a favor from a friend that has worked on AC. You will have saved $$ by getting your own parts and some shops won't help you since they want to mark up the parts like crazy