A/c compressor/clutch bearing question

I have been attempting to troubleshoot the compressor. Clutch cycles on & off. High pressure was too high. i had it evacuated, changed out the drier, pulled a vacuum. It held pressure over night. Recharged . i heated the garage to 70 & warmed the truck up. It is still cycling on & off. The high is at least 170 before the clutch cycles off & then it drops. Low is 15 & then it rises when the clutch cycles off. Blowing super cold air.

Maybe I did this backbuttwards, however last night I pulled out the handy stethoscope. Being that it's difficult to listen directly to a cycling clutch, i used the bracket & can hear a distinct rattle of sorts only when the clutch is disengaged. I can't pick up any consistently odd noises from the compressor. No rattle of sorts when the clutch is engaged.
I found a Denso troubleshooter guide. It stated if there was a rattle when the clutch was disengaged, check the bearing. If there was a constant rattle from the compressor, check the bearing.
Are there two bearings? One clutch, one compressor? I have only seen reference to a clutch bearing. Or is it simply that there is the one & a disengaged clutch rattle would come 1st & then it would progress to a consistent rattle? Like many others before me, the "predict the future quandry" is clutch vs compressor.

 

It’s actually very simple to remove the clutch Assembly, you can do that while it’s on the truck.

You can inspect the clutch and the clutch bearing as it comes off together.

And you can replace that whole clutch assembly and bearing,
Typically this bearing goes out 1st

 

How did you determine the amount of oil to add to the system after it was recharged?

The correct amount of oil is a deal breaker if it’s not correct, too much or too little and the compressor will fail.

 

From what I understood, since I did not remove the compressor, what was in the refrigerant was enough. However, the instructions for replacing the drier stated to add 20ml to the out port.

 

Although now you have me wondering because after doing the drier, the site glass was consistently off white. Different than seeing froth or bubbles.

 

on the compressor clutch there is one bearing, this is what allows the pulley to spin freely when the clutch is not engaged. When the clutch is engaged and the compressor is turning the bearing insides the compressor are being used.

 

My compressor is an aftermarket but the same thing,
Here is my old clutch and bearing is bad.
There is one center bolt that holds it on and the pry the clutch assembly off

 

I had an AC line that got a hole in it in the spring and all the fluids came out.

The AC place fixed the line and recharged the system,

3 months later my AC compressor locks up now until the motor is at temperature,

They probably put the wrong amount of oil in the system.
Unless you drain the compressor and flush the complete system there's no way to know the amount of oil in the system and damage will happen months later.
I'm going to have to now have a new compressor, dryer and possibly more to get it all balanced again

 

excellent pictures… on 1997Tacomav6 last picture shows what I forgot to post in my prior… there is a selective washer, the copper looking washer on the inside if the snout, and its purpose is to space the clutch plate sufficiently far enough away from the magnetic base so that it doesn’t drag but not so far that the magnetic field cant pull it in when energized.

 

So this is where I tilt a bit & why I asked if there were two bearings. When the bearing is faulty, since it is spinning whether or not the clutch is engaged, why would it only rattle when the clutch is disengaged?

 

I did read about this & checked the gap. It passed.

 

Thank you. These will be very helpful….
Really wish I had done this before it got cold out. Time flew by. I had not realized about ambient temps being important for running pressure testing. I’d wait til the spring, however it’d be helpful to have defrost now/soon.

 

Is the clutch turning when it's engaged and disengaged both

 

no. It’s functioning properly in that respect. The Denso troubleshooter stated if there was a rattle when disengaged, then check the bearing. If there was a rattle all the time from the compressor, check the bearing. I am hearing a rattle when the clutch is disengaged.

 

Today I also swear I hear a faint noise. Well, I heard it last night, but it had been running. It’s Kinda like random static. The truck has been sitting over night. I can’t pick up anything with the stethoscope though.

 

there are multiple bearings because… if you look close at the two pieces that make the compressor clutch assembly that the piece with the snout has internal splines. These splines lock into the compressor shaft. The other part, the magnetic clutch part that has the bearing and where the belt rides, needs to spin freely when the compressor is not in use. When power is applied to the magnetic clutch the magnetic field pulls the outer part in and locks the two pieces together and the compressor spins.

 

oh! Ok. That makes more sense. That’s why I asked if there was more than one. Well, I asked because of the Denso troubleshooter info.

 

they mentioned it for the following reason… as soon as the magnetic clutch disengages that particular bearing goes from 0 rpm to engine rpm, instantly. If there are any flaws in the bearing that’s when it will show unless it is so bad that it makes noise all the time.

 

Thank you. I like to know how things work, so I appreciate you taking the time to explain.