clutch or compressor?

[james t]

Okay, wife's car is stranded at the mall. Ive taken off work today so i can get it towed to the house and fix it. I know its not an Explorer, but its an 01 3.8l V6 Mustang and all the A/C components are the same as the 4liter Ex as far as i know. Car has 55k miles and has never had any A/C work done on it.

Either the compressor or the compressor clutch has been making noise the past few days. Last night it locked up and broke the belt. As of yesterday the A/C still blew ice cold and had a full charge when i checked it. Is it possible (fingers crossed) that i only need to replace the clutch? How do i tell if the compressor is locked or just the clutch took a dump?

Pardon the newb type questions but im an idiot when it comes to A/C as ive never had to work on A/C much before. I know if its the actual compressor that ill also have to replace all the other "consumables". I will try to update this thread to help you help me diagnose later on today once i get it home.

Thanks.

 

[shamaal]

Assuming the compressors like the ones on the Explorers (FS10).
Engine off of course.

1. Remove belt, spin clutch. If it does not move, binds or makes noise - bad clutch.
2. Put wrench on bolt in center of clutch. Should turn with slight resistance, you will feel the compressor compressing - If not - compressor is bad
3. If you want get fancy, supply +12VDC to compressor and repeat step #2. If it does not turn clutch is bad.

The clutch is replaceable, I've never done it; most people replace entire assy. I've attached a picture.
Good Luck!

 

[james t]

Instead of having it towed, i soaked the inside of the clutch with WD-40, threw a new belt on it and drove it home. The lube got the pulley broke loose and i was able to limp it the 6 miles home.

From what i can tell the compressor is good. Turning it with a wrench it feels fine. Slight resistance with a little "puff" feeling through the wrench. The clutch is toast. The balls in the bearing is exposed and there is a lot of slop in the pulley. Ive got the armature off and im waiting for it to cool down so i can slide everything else off.

 

[Glacier991]

Now someone jump in and help explain if I am wrong.... in "normal" operation, the clutch is either "on" and locked, and turning the compressor, or it is "Off" and unlocked and freewheeling and the compressor is off.

If the clutch fails, and binds up, is that not equivalent to the clutch being engaged, hence the compressor will always be "on" ?

In other words, a clutch failure does not seem to explain the locked up/no rotation/"breaks belt" scenario. Only a siezed compressor would exhibit that symptom.

Am I somehow missing something?

 

[james t]

I finished it a few hours ago and it indeed was only the clutch. After installing the new one it now works great. The compressor cycles normally as it should and its got a full charge. Ive always been told that if the clutch is gone then the compressor probably is too. This time wasnt the case.

Glacier- the clutch pulley bearing was so worn that the pulley itself seized. I broke it loose by tapping on it with a hammer and spraying WD-40 down inside it (gap between the armature and pulley assembly) and this broke it loose. This allowed me to throw a new belt on it and make the few minute drive home so i could fix it. The actual clutch itself was not locked up, its just that the wear was so extreme the pulley locked up. There were bits of bearing shavings sprayed all over and you could physically move the pulley up and down .1-.2".

FYI- the compressor on the car is an FS-15. The instructions said to remove the compressor from the car to install a new clutch but i got the new one on with the compressor on the car.

 

[shamaal]

Now someone jump in and help explain if I am wrong.... in "normal" operation, the clutch is either "on" and locked, and turning the compressor, or it is "Off" and unlocked and freewheeling and the compressor is off.

If the clutch fails, and binds up, is that not equivalent to the clutch being engaged, hence the compressor will always be "on" ?

In other words, a clutch failure does not seem to explain the locked up/no rotation/"breaks belt" scenario. Only a siezed compressor would exhibit that symptom.

Am I somehow missing something?

You're not wrong, but I'll jump in any way. I just answer the questions as posed. The facts are the belt broke, the clutch was bad, repair has fixed problem. While not at the same level as a virgin birth or Santa Claus, the logic behind it appears to be a mystery.

I know nothing of Mustangs, but I'd spin the rest of the pulleys on the belt to satisfy myself that something else isn't going.

 

[ChasAld]

Now someone jump in and help explain if I am wrong.... in "normal" operation, the clutch is either "on" and locked, and turning the compressor, or it is "Off" and unlocked and freewheeling and the compressor is off.

If the clutch fails, and binds up, is that not equivalent to the clutch being engaged, hence the compressor will always be "on" ?

In other words, a clutch failure does not seem to explain the locked up/no rotation/"breaks belt" scenario. Only a siezed compressor would exhibit that symptom.

Am I somehow missing something?

Glacier:

You are correct as far as you go. Remember that the clutch is an electromechanical device with very close tolerances between the disc and the drive sheave. The bearings are turning (as is the drive sheave) anytime the engine is running. The clutch just transfers energy to turn the compressor when the clutch is energized (turned on). It is possible, with a bearing failure, that the drive pulley will shift outward far enough to jam on the outboard disc and make it appear that the compressor is the problem. Some times if the compressor is the problem it will tear off the flexible tabs on the disc when the clutch is engaged.

Charles

 

[james t]

It is possible, with a bearing failure, that the drive pulley will shift outward far enough to jam on the outboard disc and make it appear that the compressor is the problem.

That is, in a nutshell, exactly what happened. It had nothing to do with actual clutch engagement... the bearing was physically so worn out that the pulley walked over onto the armature or outboard disc or whatever it was. Hence, tapping on it with a hammer got it lined back up.

Shamaal- i checked all the others when i had the belt off and all is good. It was just a POS factory pulley/clutch assembly. Obviously not a very common failure.

 

[shamaal]

Makes sense to me. Kills that mystery. I'll go back to pondering that if Santa walks backwards does he proclaim, "Oh, Oh, Oh"?

Happy holidays.

 

[Glacier991]

I'm still a little confused, but then that's pretty much a normal experience. I am sure I got up off my lazy a** and went out and eyeballed it it would make more sense. thanks all for the replies.

ps. the day I stop learning or wanting to - shoot me.