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AC compressor repair without opening system

33K views 90 replies 13 participants last post by  gordo999 
#1 ·
Compressor locked up and started smoking from the center shaft.

I heard grinding noises but is it possible it was the pulley or bearings grinding on the clutch as opposed to insides getting torn up?

Is it possible to replace the entire clutch assembly without removing the compressor and having to vacuum and recharge refrigerant?

If the insides were getting torn up, would I be able to tell from this approach?
 
#3 ·
Yes you could replace just the clutch without removing the compressor, but from the sound of it, the internals are fried. hopefully it didn't send to much metal through your ac lines.

The compressors are pretty easy to get to and change in these things. But this might be better suited for a shop so that they can flush out the crap out of your lines and replace the other stuff so all of that metal doesn't go into your new compressor and wipe that one out too.
 
#4 ·
^ that.

In general, when the clutch goes bad, the compressor simply fails to come on.

When the internals have crunched, you get lockup and smoke and bad, bad things...
 
#5 ·
Take the belt off and see if the pulley and shaft will rotate. If the pulley rotates but the shaft doesn't then the bearings are good. If the pulley and shaft rotate together then you have your compressor is likely good but the pulley will have to come off for inspection. If the pulley rotates freely then put a socket on the pulley nut and rotate it and if it doesn't turn then your compressor is toast.
 
#6 ·
Would anyone be willing to list out some troubleshooting steps? I don't want to take the compressor off and open the system unnecessarily. I'm not in denial! I just figured these troubleshooting steps might be helpful for others too as it seems to be a common issue

The above tips from LexTempus seems to be a good start.

And what exactly does it mean when "the internals are fried"? If there is a common scenario, how does that exactly happen? I've read plenty of descriptions about metal shavings in the AC system but not any helpful explanations.

Thanks. Look forward to learning more.
 
#7 ·
See if you can turn just the clutch part, the outside part of the clutch assembly. If that turns then the compressor is still good. Try turning the pulley where the belt rides, if that spins good and isnt tight, then the clutch bearing isnt your problem.

I've changed a clutch assembly because the bearing went bad and didnt have to take the compressor out or evacuate the system. The bearing going bad caused the clutch to start to continuously drag and wear it down, so you may see the filings from that. eventually it wont pull in anymore as there is nothing left to grab! Once you take the belt off and spin the pulley and clutch, I think you will know what your up against.
 
#8 ·
Thank you, sfeaver.

For background, the first photo shows what happened when my compressor seemed to lock up and I booked it home two blocks before the engine shutdown. That center plastic cap is now toast.

With the serpentine belt off, I was able to turn the clutch assembly (the gold part) about a quarter turn with two firm hands but no further.

I was able to turn the pulley but it was very tight too.

I was hoping to take the clutch assembly off to take a better look before extracting the entire compressor, but the second photo shows that a special tool is required.

Is this a stock compressor, in which case where do I get the tool? Any advice on next steps?
 

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#9 ·
I would guess that the bearing burned up and took out the plastic center cap.

Yes, you need a compressor clutch tool; they're on Amazon, eBay, etc. Along with a replacement clutch, which usually is on eBay.
 
#10 ·
Yes you need a puller tool and an install tool.. Autozone may loan them out, or other auto parts stores.

That looks like the clutch bearing is gone, as it looks like there is a bigger gap at the top than the bottom from clutch plate to pulley. Can you turn the clutch plate more than a quarter turn if you pull the pulley back a bit? Maybe the whole thing needs to be replaced, but cant be totally sure until you pull the clutch plate out a bit. Did it cool okay until this happened?
 
#11 ·
replace the compressor. its old anyway. the clutch, clutch coil, pulley brg, shaft seal, shaft brg and compressor all have done 12 or 15 years of work. now, u stated that u can't turn the clutch, so that means the comp has failed internally. the whole front nose of the compressor has been hot enough to melt plastic and discolour steel. the brg sounds like its failing too(overheated?) most likely the coil has melted also( you wont know till u pull the clutch off or at least test the coil for continuity). also there's no telling what damage has been done to the shaft seal or how much longer it will hold freon in the system. so, you'd be better off renewing the entire compressor rather than spending your money on a tool you'll only use once. whats a comp worth in the states? 250?300?
its been my experience that its not worth trying to repair parts of a compressor for these reasons.
its also been my experience, that by pulling the clutch off the shaft that u run a 50/50 chance of having the seal leak just because you've disturbed things and its old.
have your freon recovered and replace the whole unit.

and don't get a no-name chinese comp. they are NO GOOD!!
 
#12 ·
Thank you, sfeaver and stanvalp. All opinions and input welcome.

stanvalp said:
replace the compressor. its old anyway. the clutch, clutch coil, pulley brg, shaft seal, shaft brg and compressor all have done 12 or 15 years of work.
Actually 21 years! OK, OK, I suppose I got my money's worth from that part.

stanvalp said:
the whole front nose of the compressor has been hot enough to melt plastic and discolour steel... also there's no telling what damage has been done to the shaft seal or how much longer it will hold freon in the system.
I suppose it's reasonable to think that smoke and discolored steel is a good indicator it's asking for mercy! Thank you for the reality check.

stanvalp said:
and don't get a no-name chinese comp. they are NO GOOD!!
I already bought a UAC compressor 20144c for $136 on Amazon. I didn't see any red flags based on product reviews or comments about the brand so I'm sticking with it.

My next step
I'm going to be cautiously optimistic that this is just a clutch/pulley issue and not a bigger compressor issue resulting in metal shavings being spit throughout the system.

So I'm going to keep hope alive and remove the compressor to inspect. If all looks good, I'll replace the compressor/accumulator/orifice tube, recharge, and move on.

I was hoping I didn't have to open up the system, but that looks unavoidable, so now I'm just hoping I don't need to replace the condenser as well (and other parts?) and flush the whole system. If that needs to happen, you'll be hearing from me again! Continued input welcome.
 
#14 ·
In my opinion if you're opening up the system and replacing all that stuff you might as well flush the entire system. The flush detergent is cheap enough and will get any suspected crap out of the pipes. The delivery mechanism can be complicated though. Best to buy it in pressurized cans.
 
#15 ·
That hose you listed is for a van with the upfitter package, YF7 I believe is the RPO code. A conversion van. If you dont have that, the lines will be different.

That being said, if your going to pull it apart, look at the orifice tube and see if its covered in shavings. Then youll know how had things are. Do you know if the compressor spins by hand? Still can just be the clutch bearing that went and didnt cause any internal system damage.
 
#16 ·
I cannot really come up with a good reason NOT to flush the system.
If you are not the original owner, you cannot vouch for what may be inside the system.
Leak stop goop, FOD, Dessicant particles, black goo from the wear of the compressor rings, small rubber particles etc. If anything happens that you have to return your compressor for warranty, you could be asked for proof that you flushed it. Receipt for the flush solvent and accumulator should not be discarded for this reason. Depending on who you bought your parts from, they can be strict with the warranty requirements because a lot of shadetree guys ruin compressors.
 
#17 ·
sfeaver, clutch assembly turns a little bit by hand but is very hard. Given this is a 21-year-old part, even if it is just the clutch I've decided to let it rest in peace!

Thanks all for the suggestion to flush. I will take a look inside the system and decide.

Heres the part I'm wondering needs to be replaced. Behind the accumulator. I thought it was the link I posted above or something like it. Unless I hear it needs to be replaced, I will leave it alone
 

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#18 ·
The metal can behind is just a muffler or something like that. You should be fine reusing it. The pressure switch attached to the accumulator I definitely recommend replacing. I just had mine fail and I roasted for two days before I narrowed it down to that part. Spent $12 and now I'm chilly willy again. That is a wear item for sure. The switch inside closes every few seconds when the ac is running. I pried mine open and the contacts were corroded and pitted from arcing.
 
#19 ·
The metal can shouldn't need to be replaced.

Like Jack said, replace the pressure cycling switch on the accumulator. It went bad on my '93 Bravada and we had to jump the switch to get AC to get the 300 miles home...then replaced the switch.
 
#20 ·
97cargocrawler said:
The pressure switch attached to the accumulator I definitely recommend replacing
Thanks, 97cargocrawler. That can be replaced without opening up the system, correct? And could you point me to the specific part? I browsed Amazon but can't tell which matches what you are talking about. Thanks!
 
#23 ·
Other than opening the system up and venting whatever coolant you have to the atmosphere ( which is a no no ) you can rent a vacuum pump from autozone/ part store that rents tools. You'll need a line gauge set, which you can rent or buy ( I recommend buy ). It's really not all that hard to do automotive A/C on these vans. The biggest problems that will cause a failure is to not fully vac the system to get rid of all moisture in the system, not flushing out components that could have collected metal shavings/etc with a flush gun/kit and over/under charging the system. Watch a few videos if you are nervous, there's a wealth of info out there on how to do it. I managed to snag an A/C line set and a vacuum pump off of CL for less than 70 bucks.
 
#24 ·
Leeann_93 said:
Correct. There's a schrader valve behind it, so nothing leaks when you R&R it.

From RockAuto:
http://www.rockauto.com/en/moreinfo.php ... 78&jsn=504

Under A/C Clutch Switch (accumulator mounted)
Under Electrical Switch & Relay
Regarding this switch, I noticed that the Four Seasons version of this switch is 1/3rd the price of the ACDelco. Can anyone with personal experience tell me why I should or shouldn't just buy the Four Seasons switch?
 
#25 ·
For Jawon (OP), I just found this YouTube video that might be useful to you:

"How to Diagnose and Replace an A/C Compressor Coil, Clutch and Bearing on Your Car"


The only thing I would recommend you NOT do that he shows in the video is to hit your ratchet with a hammer to loosen the clutch nut (really bad for the paws in the ratchet), use a breaker bar instead.
 
#26 ·
babblefish said:
Regarding this switch, I noticed that the Four Seasons version of this switch is 1/3rd the price of the ACDelco. Can anyone with personal experience tell me why I should or shouldn't just buy the Four Seasons switch?
I opened up my AcDelco switch to verify it was fukkake. I was gonna order a new AcDelco switch from Amazingzon for like $18 but didn't want to wait another day and sweat like a piggy. So I ventured up the street to O'Really's and got a Murray brand switch for $12. Place utility. I figure it's a regular service item and I will replace it from now on every year so quality is perhaps a non-issue.

The internals of the AcD switch looked pretty cheesy too.

20170522_194655.jpg


I bent up the tab to get a better view of the contacts:

20170522_195247.jpg


Probably 99% of the members here need a new switch. Mine was so jacked it was only occasionally making good enough contact to send enough voltage to the relay that kicks on the compressor clutch. At times I measured only 3V getting through the switch...instead of like 13.5v. The result was sometimes the air blew nice and cold but only for a few minutes, then warm. Then a while later cold..then warm..then...
 
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