AC clutch 2006 Yukon XL- loud squeal

[Shielahs]

I had a squeal when starting my car that happened after the water pump was replaced.
We changed the serpentine belt, the AC compressor belt, and the tensioner pulley
There’s a small squeal when you start the car but when you turn on the AC button and it’s squeals like crazy. The AC is still cold and blows great. So I’m thinking it’s the AC clutch?
Has anybody ever replaced this before or hit any thing similar? Could I relay cause this as well?
It still turns when on , feels tight when I manually turn it . Small puff of rust color air came out at initial startup .

 

[nick0789]

Did this only start after the water pump replacement? If so, are the other pulleys clean / has there been any transfer of residual coolant from another pulley onto the new belt?

There is also the idler pulley.

One way to test the clutch is to remove the AC belt. Spin the pulley by hand and see if it’s rough, making noise.c or has any other issue. You can also start the vehicle and see if you hear the squeal. If you hear a squeal while the AC belt is off then I’d suspect coolant or something else on one of the drive pulleys.

 

[Joseph Garcia]

Give us your responses to @nick0789 questions above, and we will be in a better position to help you narrow the cause of this issue. You mentioned that you replaced a belt tensioner assembly. I'm not totally familiar with you model year truck, but my 07 L92 has 2 belt tensioner assemblies. Does your truck have 2 belt tensioner assemblies? If yes, perhaps the other tensioner belt assembly needs replacement as well.

 

[Shielahs]

Did this only start after the water pump replacement? If so, are the other pulleys clean / has there been any transfer of residual coolant from another pulley onto the new belt?

There is also the idler pulley.

One way to test the clutch is to remove the AC belt. Spin the pulley by hand and see if it’s rough, making noise.c or has any other issue. You can also start the vehicle and see if you hear the squeal. If you hear a squeal while the AC belt is off then I’d suspect coolant or something else on one of the drive pulleys.

Yes, it started after I replaced the water pump and I did spill a little bit of coolant on the belt, but I replaced the belt to see if that was the issue and it still squeezed - only with the ac turned on.
it went a whole day without squealing initially, and it started the day after.
This was the new belt I replaced because there was a spot on it where that got a small splash of coolant on it, I did replace the new one again- it made no difference in sound . We took the belt off and the squealing noise was still there - only when we engaged the AC .
I can move the pulley, but it’s tight to Move. It doesn’t spin like all the other ones do I can spin those the AC one is tight. I can turn it though

 

[Shielahs]

@nick0789 I replaced the tensioner that was recommended when I replaced the AC belt. The other one seems fine. The squeal only happens when we push the AC button with the belts off or in -
There was a place I could post a video for you to see and hear I would, but I don’t see a place to do that. A touch like a few drops of antifreeze got on the new belt. The belt looked fine. I replaced the belt again just to see if it was that the cause - it was not, so I put the first new belt back on .
As I said when we start the car, there’s a small chirp when we start then there’s no noise until we turn on the AC. That’s when it starts to squeal with or without the belt on. The Pulley on the AC compressor is hard to turn all the others spin.

Give us your responses to @nick0789 questions above, and we will be in a better position to help you narrow the cause of this issue. You mentioned that you replaced a belt tensioner assembly. I'm not totally familiar with you model year truck, but my 07 L92 has 2 belt tensioner assemblies. Does your truck have 2 belt tensioner assemblies? If yes, perhaps the other tensioner belt assembly needs replacement as well.

 

[PPV_2018]

It’s possible that there is residual anitfreeze still stuck in the pulley grooves causing the noise since it’s guaranteed coolant is going everywhere when you change the water pump out and if that’s the case eventually the noise will fade out on it’s own.

Other than that, you could have bearings failing in one of the pulleys, like the a/c compressor pulley, water pump, idler/tensioner..