AC clutch pulley will not turn (2 Viewers)

[Takeadoe]

First, a Happy Thanksgiving to all. I give thanks to all who contribute on this site. I’m not a mechanic by even the loosest of definitions, but I’m crazy enough to try! Thanks to posts here I recently changed my power steering pump and shocks all the way around. I thought I was done for a while, not! I pulled in the garage after work yesterday and smoke was rolling out from under the hood. It was obvious where it was coming from...the AC compressor clutch/compressor. Today I had my son turn the engine over while I watched to see what the pulley and clutch were doing. The engine struggled and it was clear it wasn’t going to turn over. I took the belt off and it started right up. The pulley was frozen. Is there any chance it could just be the clutch or is it safe to assume that the compressor is toast as well? I don’t plan to tackle this myself as I have no experience or tools for AC work. However, I’d like to arm myself with some knowledge before I go to a new mechanic. One other note that may or may not be relevant. With the vehicle running, after removing the belt, I turned the AC on and I noticed a change in the sound of the engine. I turned it off, and again the sound of the engine changed. Again, there was no belt attached to the compressor pulley when I did this. I appreciate any time you may be able to spare!

Mike

Mike

 

[Rusty Marlin]

If the clutch is engaged and the compressor is not turning, the compressor is probably toast.
Depending on how it locked up, if it grenaded internally, you could be looking at a new condenser, dryer and expansion valve.
When the mechanic takes the compressor off the rig he/she should be able to look for and see if there are metal shavings in the high pressure line to the condenser. If there are no metal shavings you may be lucky and just need a new compressor and dryer (the dryer should be changed any time the system is opened.)

 

[flintknapper]

Mike, you can test the compressor on the vehicle and get some idea what the issue is.

With the belt off....you should be able to freely spin the grooved portion of the pulley. It should not be locked up or gritty feeling in any way. It normally free 'wheels' until the A/C unit is turned on and calls for the magnetic clutch to 'lock up' to it.

IF the pulley DOES spin freely then move on to testing the compressor. They are NOT always locked up because of internal damage. Sometimes as a result of infrequent use...the half moon bearings on the swash plate simply bind up and they can often be dislodged by moving the compressor shaft both directions (forward and backward). IF you can not move the compressor either direction...then it is fair to assume internal damage.

The best way to grab the outermost part of the clutch is to use a 'locking oil filter wrench'. Just lock onto the outermost circumference of the clutch and try to rock it both directions. It will either free it up....or not. If not...then have your answer (its the compressor). You can pick up the tool at HB for $10.00

To answer your question about replacing only the clutch, Yes you can buy only that item....but it approaches the cost of a good 'reman' compressor....so most folks don't fool with it.

 

[Takeadoe]

If the clutch is engaged and the compressor is not turning, the compressor is probably toast.
Depending on how it locked up, if it grenaded internally, you could be looking at a new condenser, dryer and expansion valve.
When the mechanic takes the compressor off the rig he/she should be able to look for and see if there are metal shavings in the high pressure line to the condenser. If there are no metal shavings you may be lucky and just need a new compressor and dryer (the dryer should be changed any time the system is opened.)

Thank you!! Please forgive my ignorance, but I gather I should be able to look at the clutch and tell if it is engaged by its position. I gather that it is since the AC was on when it stopped working.

 

[flintknapper]

Thank you!! Please forgive my ignorance, but I gather I should be able to look at the clutch and tell if it is engaged by its position. I gather that it is since the AC was on when it stopped working.

The clutch is electro-magnetic....so it only engages when a 12VDC power supply is applied.

When your engine is running the belt for the A/C compressor (goes from your crank pulley to the A/C compressor pulley) is turning the free wheeling pulley on the compressor. So it's turning any time your engine is on. When you select A/C at the dash, 12volts is sent to the Clutch Coil on the compressor and it electromagnetically pulls the clutch onto the drive face of the clutch pulley. The clutch is splined or keyed (depending on the style) to the compressor shaft....so the compressor becomes 'driven' at this point.

Below is a pic of the set up that is typical of ALL compressors (though the pulley is different in this case).

The clutch will normally 'engage' with a clicking sound if it working. Also, you can visually see it take up the 'air gap' (usually only .020") AND you'll see the compressor clutch itself begin turn (if it can).

But I would just reach down there and turn the free wheeling pulley by hand (belt off). That will tell you right away if the bearing in the pulley is seized (which might be your only problem). The bearing itself is replaceable. IF the pulley is good, then we move on to determine if the compressor is temporarily 'stuck' or if it worse (seized due to internal damage).

If you can get us this information....we are happy to help guide you the rest of the way as to what your options are.

 

[Takeadoe]

Mike, you can test the compressor on the vehicle and get some idea what the issue is.

With the belt off....you should be able to freely spin the grooved portion of the pulley. It should not be locked up or gritty feeling in any way. It normally free 'wheels' until the A/C unit is turned on and calls for the magnetic clutch to 'lock up' to it.

IF the pulley DOES spin freely then move on to testing the compressor. They are NOT always locked up because of internal damage. Sometimes as a result of infrequent use...the half moon bearings on the swash plate simply bind up and they can often be dislodged by moving the compressor shaft both directions (forward and backward). IF you can not move the compressor either direction...then it is fair to assume internal damage.

The best way to grab the outermost part of the clutch is to use a 'locking oil filter wrench'. Just lock onto the outermost circumference of the clutch and try to rock it both directions. It will either free it up....or not. If not...then have your answer (its the compressor). You can pick up the tool at HB for $10.00

To answer your question about replacing only the clutch, Yes you can buy only that item....but it approaches the cost of a good 'reman' compressor....so most folks don't fool with it.

View attachment 2506923

View attachment 2506924

Wow! Sorry, somehow I missed this! So nice of you to lend a hand!! I will try turning it with said wrench, but it is not budging with my bare hands .

 

[flintknapper]

Wow! Sorry, somehow I missed this! So nice of you to lend a hand!! I will try turning it with said wrench, but it is not budging with my bare hands .

If there is pressure in the system....you won't be able to turn the clutch by hand (or not easily) but you should be able to spin the pulley very easily. IF the pulley will not spin, then the bearing is shot at the very least. IF the pulley DOES spin but the clutch won't move (with the pliers) then you're looking at a new compressor.

 

[JimJam]

The clutch is electro-magnetic....so it only engages when a 12VDC power supply is applied.

When your engine is running the belt for the A/C compressor (goes from your crank pulley to the A/C compressor pulley) is turning the free wheeling pulley on the compressor. So it's turning any time your engine is on. When you select A/C at the dash, 12volts is sent to the Clutch Coil on the compressor and it electromagnetically pulls the clutch onto the drive face of the clutch pulley. The clutch is splined or keyed (depending on the style) to the compressor shaft....so the compressor becomes 'driven' at this point.

Below is a pic of the set up that is typical of ALL compressors (though the pulley is different in this case).

View attachment 2507014

The clutch will normally 'engage' with a clicking sound if it working. Also, you can visually see it take up the 'air gap' (usually only .020") AND you'll see the compressor clutch itself begin turn (if it can).

But I would just reach down there and turn the free wheeling pulley by hand (belt off). That will tell you right away if the bearing in the pulley is seized (which might be your only problem). The bearing itself is replaceable. IF the pulley is good, then we move on to determine if the compressor is temporarily 'stuck' or if it worse (seized due to internal damage).

If you can get us this information....we are happy to help guide you the rest of the way as to what your options are.

I have this pully set up.. quick question.. how in bloody hell are we supposed to check this gap!! They could have made it easy and put some slots in the pully for the feeler gauges at least.

 

[flintknapper]

I have this pully set up.. quick question.. how in bloody hell are we supposed to check this gap!! They could have made it easy and put some slots in the pulley for the feeler gauges at least.

^^^^

They could have put the compressor up higher on the engine too. Just be happy it isn't a 100 series which is REALLY tucked away.

 

[JimJam]

yep, 100 series it is.. changing the clutch kit was simple but usually the clutch plate sits flush with the pully wheel face.. only see the picture in your post where the clutch plate actually sits inside the pully wheel.. doesn't seem like a logical method to check the correct gap with this design.

 

[flintknapper]

yep, 100 series it is.. changing the clutch kit was simple but usually the clutch plate sits flush with the pully wheel face.. only see the picture in your post where the clutch plate actually sits inside the pully wheel.. doesn't seem like a logical method to check the correct gap with this design.

The pic provided is a 'generic' representation and I noted in my post that the 'pulley' is different on our L/C's. You can check the 'Air Gap' with a feeler gauge.

 

[JimJam]

The pic provided is a 'generic' representation and I noted in my post that the 'pulley' is different on our L/C's. You can check the 'Air Gap' with a feeler gauge.

 

[JimJam]

Funny mate, this set-up is exactly what I have.. it's what I pulled out and what I replaced it with.. it's imported from Japan though so maybe that's why.. all good, keep on wagoneering, when I figure it out I'll post it here 🖐

 

[JimJam]

Funny mate, this set-up is exactly what I have.. it's what I pulled out and what I replaced it with.. it's imported from Japan though so maybe that's why.. all good, keep on wagoneering, when I figure it out I'll post it here 🖐

Quick update.. I ended up machining a slot in the pully wheel for the feeler gauges to access the gap.. easiest solution in my opinion. no removal required and the quick access is always there for tightening in the future (simply have to remove belt to access it).

 

[sonocruiser]

Mike, you can test the compressor on the vehicle and get some idea what the issue is.

With the belt off....you should be able to freely spin the grooved portion of the pulley. It should not be locked up or gritty feeling in any way. It normally free 'wheels' until the A/C unit is turned on and calls for the magnetic clutch to 'lock up' to it.

IF the pulley DOES spin freely then move on to testing the compressor. They are NOT always locked up because of internal damage. Sometimes as a result of infrequent use...the half moon bearings on the swash plate simply bind up and they can often be dislodged by moving the compressor shaft both directions (forward and backward). IF you can not move the compressor either direction...then it is fair to assume internal damage.

The best way to grab the outermost part of the clutch is to use a 'locking oil filter wrench'. Just lock onto the outermost circumference of the clutch and try to rock it both directions. It will either free it up....or not. If not...then have your answer (its the compressor). You can pick up the tool at HB for $10.00

To answer your question about replacing only the clutch, Yes you can buy only that item....but it approaches the cost of a good 'reman' compressor....so most folks don't fool with it.

Is there an easy way to attempt to dislodge the half moon bearings by moving the shaft forward and backward? I went through and tested the components of the compressor the way you said, with the Harbor Freight wrench and everything. With belt off, pulley spins freely, clutch rocks easily, idler pulley has a new NSK bearing and spins freely. Belts are all Toyota.

My problem is a persistent squeak/squeal sound at idle with clutch engaged that goes away with higher RPMs. At idle, clutch engages, compressor spins, and air blows cold, but noise persists. I also noticed some difficulty spinning at low RPM, clutch rotating slightly, stopping, rotating slightly, stopping, almost as if not fully engaged. Additionally, once at a red light I heard a loud clunk/squeal upon engagement of the clutch which I assumed to be the clutch engaging fully but compressor not spinning, with the belt just slipping on the pulley.

 

[flintknapper]

Is there an easy way to attempt to dislodge the half moon bearings by moving the shaft forward and backward? I went through and tested the components of the compressor the way you said, with the Harbor Freight wrench and everything. With belt off, pulley spins freely, clutch rocks easily, idler pulley has a new NSK bearing and spins freely. Belts are all Toyota.

My problem is a persistent squeak/squeal sound at idle with clutch engaged that goes away with higher RPMs. At idle, clutch engages, compressor spins, and air blows cold, but noise persists. I also noticed some difficulty spinning at low RPM, clutch rotating slightly, stopping, rotating slightly, stopping, almost as if not fully engaged. Additionally, once at a red light I heard a loud clunk/squeal upon engagement of the clutch which I assumed to be the clutch engaging fully but compressor not spinning, with the belt just slipping on the pulley.

Sounds like you have a belt (A/C belt slipping). Even if seemingly 'tight' enough....it might be 'glazed'.

IF your belt is very old or has been slipping, I'd put a new "Bando" belt on it (raw edge, cogged), tighten it and see if that solves your problem.

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[sonocruiser]

Sounds like you have a belt (A/C belt slipping). Even if seemingly 'tight' enough....it might be 'glazed'.

IF your belt is very old or has been slipping, I'd put a new "Bando" belt on it (raw edge, cogged), tighten it and see if that solves your problem.

I got around to taking everything apart last week along with a few other things and you were spot on. No issues a week later. Thanks again!