1974 Fleetwood AC squealin

[ithaca1230]

Took the family for a drive Sunday and turned the AC on and after a few compressor started squealing. Turned it off and it stopped immediately. Im guessing the compressor needs work. My question to you all is should I try and fix this one or just replace it.

Thanks

Billy

[WTL]

Is it the belt(s)? 

Make sure, my 69 is a battle getting the belts not to squeel.

[ithaca1230]

Pretty sure it was the compressor.

[WTL]

Why? 

A new compressor is at least $300. The belts are cheap.  Make dead sure, cause what you describe, with the squeel only occurring with the compressor being on, is exactly how my car is right this moment.  In my case, it's the belts. 

["Cadillac Kid" Greg Surfas 15364]

William
The technical question is, is this a squeal or a screech.  I would try belts first. I believe you have a single belt that serves the AC compressor and the power steering pump.  Belt adjustment is via the ps pump.  For whatever reason it seems that the sixe listed requires adjusting the Pump to the end of adjustment travel when new and that today’s belts seem to stretch.
Rather than bemoaning the quality what works is to get a belt 1 inch shorter than specs call for.
Also be sure the belt you get is the correct width and angle so it rides correctly in the pulley. Again you will find several widths listed as correct but check your FSM. I believe it is 0.491 inches but chech.
Try the belt and if the noise is a screech well go from there.
Greg Surfas

[ithaca1230]

William
The technical question is, is this a squeal or a screech.  I would try belts first. I believe you have a single belt that serves the AC compressor and the power steering pump.  Belt adjustment is via the ps pump.  For whatever reason it seems that the sixe listed requires adjusting the Pump to the end of adjustment travel when new and that today’s belts seem to stretch.
Rather than bemoaning the quality what works is to get a belt 1 inch shorter than specs call for.
Also be sure the belt you get is the correct width and angle so it rides correctly in the pulley. Again you will find several widths listed as correct but check your FSM. I believe it is 0.491 inches but chech.
Try the belt and if the noise is a screech well go from there.
Greg Surfas

Greg,

The belts are new (last year) and I just checked them when I installed a new one for the air pump. I will check again. Pretty confident that they are the correct belt and they seemed tight last week.
I guess I would call it a screech sound.

Thanks
Billy

["Cadillac Kid" Greg Surfas 15364]

Suggest you try this.  With the engine idling turn on the AC. If there is no noise try turning the steering wheel. If you get the noise then, it suggests the belt. By the way the “correct” belt as listed in Rock Auto can be anywhere from 13/32 to 15/32, the later being closer. Check for the simple stuff first.
Greg Surfas

[ithaca1230]

Suggest you try this.  With the engine idling turn on the AC. If there is no noise try turning the steering wheel. If you get the noise then, it suggests the belt. By the way the “correct” belt as listed in Rock Auto can be anywhere from 13/32 to 15/32, the later being closer. Check for the simple stuff first.
Greg Surfas

Ok will do tonight. First time it happened we were driving approx 65mph and it started screeching. Turned off ac stopped immediately. couple miles down the road turned on ac no noise after a few miles started again. turn ac off noise goes amay. No noise at idle. I will check again when I get home.

Thanks

[Mike Josephic CLC #3877]

Do you have any spray on belt grip?  If you want to
solve this quickly and don't have a can, buy one for a
couple Dollars.

Spray on the AC/PS belt as per directions making sure
to coat it completely.  If that squeal goes away, it's 99%
sure the belt slipping.

Mike

[ithaca1230]

Do you have any spray on belt grip?  If you want to
solve this quickly and don't have a can, buy one for a
couple Dollars.

Spray on the AC/PS belt as per directions making sure
to coat it completely.  If that squeal goes away, it's 99%
sure the belt slipping.

Mike

Mike ,

Thanks will try it out and let you all know.

Billy

["Cadillac Kid" Greg Surfas 15364]

 Billy
Not critical yours but some of the new even major brands have been quite poor in quality or longevity
Greg Surfas

[ithaca1230]

Well I tried the belt grip stuff and checked the belt. No luck. now its screeching at idol when ac is turned on. I was looking on Caddidaddy site and I see they have a compressor for 410.95 this is the  detail

Number of Pulley Grooves: 1

Compressor Coil Position: 2 O'Clock

Model: GM A6

Pulley Diameter: 5"

Switch Type: Superheat

FITS:

1967-1973 Cadillac Models

1974-1975 Cadillac Deville and Eldorado Models

1976 Cadillac Deville, Eldorado and Seville Models

And a pulley. 285.00



NOS. A/C compressor single groove pulley with bearings. Includes original box. Group # 9.180 Part # 6551175

FITS:

1973 Cadillac models 2ND TYPE ONLY

1974-1975 Cadillac  models

WITH AXIAL COMPRESSOR ONLY

1976 Cadillac models EXCEPT SEVILLE

is there any other source for these parts? I'm not sure if the compressor is the correct one. What do you guys think.

Thanks

Billy

[Scot Minesinger]

I have installed at least a dozen new compressors of the 1974 thru 1976 Cadillacs (so you know the compressor is probably good) to replace bad compressors.  After start up the belt that came with the car usually squeals because it is the wrong one and not beefy enough to handle the ps and ac.  Just because a belt is new or looks good does not mean much. 

For proof positive if you buy the green backed heavy duty belts from Napa the compressor will not squeal.  You just need to order it with belt size known.  Sometimes where authentic look is not a concern I install those.

If the ac works and the belt squeals my bet is a belt.

[ithaca1230]

I have installed at least a dozen new compressors of the 1974 thru 1976 Cadillacs (so you know the compressor is probably good) to replace bad compressors.  After start up the belt that came with the car usually squeals because it is the wrong one and not beefy enough to handle the ps and ac.  Just because a belt is new or looks good does not mean much. 

For proof positive if you buy the green backed heavy duty belts from Napa the compressor will not squeal.  You just need to order it with belt size known.  Sometimes where authentic look is not a concern I install those.

If the ac works and the belt squeals my bet is a belt.

These are the belts I used. Got them from napa. AC is not working. Last year I got the compressor to turn on by replacing a switch of some sort under the hood and was trying to source some r12. Thats as far as I got. The temperature was changing with the thermostat just not cold enough. I guess I could try and tighten the belt up some more but it does seem plenty tight.

Thanks

Billy

[Scot Minesinger]

If the ac is not working even with a great belt, then OK maybe it is the compressor (or of course something else).  When I did replace the compressor and the belt squealed the ac still worked.  It was just an annoying sound - if deaf it would have been ok.

My experience with the 1974 thru 1976 Cadillacs is that the VIR is the weak point.  Rebuilds are readily available.  If the ac is fully charged for sure proof positive, and no cooling is going on the VIR is very likely an issue.  Plus these systems leak first at the VIR.  Most of the compressor failures are leaks not failure to provide ac.  Further, sometimes the hoses leak, but not too often.  All the o-rings should be replaced because that is easy and inexpensive if there is a leak.

[WTL]

On second thought, if the ac compressor were to lock up while the car was underway, that too might make the belt squeal in theory.   In that circumstances wouldn't be the belts fault.  Might explain the air conditioning not working and the squeal happening not on acceleration.  Belt lot of times will squeal on acceleration,  especially if you cock the steering one way or another too far.

[Scot Minesinger]

If the compressor locks up there will be no power steering.  When turning the steering wheel with ac on at low speed and in parking lot the belt would squeal (if it ever will) if not properly adjusted. 

[Dan LeBlanc]

Another thought - perhaps it blew the front seal and there's oil on the clutch surfaces causing them to slip.

I'd disconnect the plug for now at the compressor so if you need climate control for heat you'll at least have that.

["Cadillac Kid" Greg Surfas 15364]

William,
One more shot at the belt fitment. Does your belt ride in the pulley like this?
If so you have the right belt, and if there is still some adjustment left after you have it fully tightened we can go on to the compressor.
If you do find the compressor is bad you are going to need. Few specialty tools to replace it.  One of those will be a spammer intended to turn the compressor over with the clutch dis engaged. This is critical prior to startup as described in the FSM.
That said it might be a good time to get this tool becaus3 it will help you determine whether or not the compressor is actually bad.
Greg Surfas

[ithaca1230]

William,
One more shot at the belt fitment. Does your belt ride in the pulley like this?
If so you have the right belt, and if there is still some adjustment left after you have it fully tightened we can go on to the compressor.
If you do find the compressor is bad you are going to need. Few specialty tools to replace it.  One of those will be a spammer intended to turn the compressor over with the clutch dis engaged. This is critical prior to startup as described in the FSM.
That said it might be a good time to get this tool becaus3 it will help you determine whether or not the compressor is actually bad.
Greg Surfas

I will take another look again tonight. I am tempted to try another belt.