Brand New A/C Compressor Clutch Slipping

[DBarre]

I've got a brand new R4 compressor installed with a new condenser, drier, orifice tube, and o-rings. I vacuumed it down and started charging it with R134a. Once I got a partial charge in the system, the clutch started slipping and making this godawful screeching. I really don't want to have to send the stupid compressor back for warranty replacement.

Is there something I'm missing? Maybe there's a way to adjust the clutch so it actually engages properly. I just don't know what it is.

Any help would be appreciated.

 

[bucket]

Yeah, it happens with today's garbage parts.

Can you turn the clutch plate by hand?

 

[DBarre]

I was hoping for better luck.

I can turn it with a pair of pliers and it turns fairly easily.

 

[yevgenievich]

Check the distance between the clutch plate and the coil. It can be pressed closer if that is the issue. Also verify pressure not spiking on high side when problem occurs.

 

[Snoots]

I hate to be the one to ask this but I must.

Are you absolutely certain that it's the compressor clutch and not the belt?

Plus, what yevgenievich suggested.

 

[DBarre]

Check the distance between the clutch plate and the coil.

I've read about doing this, but how do I check it? I did notice what looked like small metal shavings around the pulley. I'm guessing that's not good!

Are you absolutely certain that it's the compressor clutch and not the belt?

I'm pretty sure it's not the belt. Brand new belts and it looked like it was turning.

 

[yevgenievich]

What is the current distance? Should be around 0.5mm-1mm
Would be good to put gauges on it when issue comes up as well

 

[DBarre]

What is the current distance?

Do I just stick a feeler gauge in between the pulley and clutch?

Would be good to put gauges on it when issue comes up as well

I had the gauges on when I was charging it, but I don't remember the exact numbers. The high pressure was still coming up and the low was coming down. It's probably got about half the refrigerant it needs and then the squealing starts. At that time, the compressor is no longer running and the high and low pressures begin to equalize. I haven't been able to charge it any more because the clutch won't fully engage. I pretty much gave up after we started getting all the cold weather.

 

[Snoots]

Just a wild guess but, got enough PAG oil in it?

 

[yevgenievich]

Not exact r4 spec but example.

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[DBarre]

Well, now that's it's hot again I got back to working on the a/c. I put another new compressor on it and had the same problem. Guess what? Snoots called it.

Are you absolutely certain that it's the compressor clutch and not the belt?

The belt was slipping! I feel dumb now.

I still haven't got it blowing cold. When I add it all up, I've already spent at least a full work week on it. Now it looks like the evaporator is clogged, so I'm going to tear into it one last time. New evaporator, orifice, and drier to go with the compressor and condenser I've already replaced. If this doesn't work, I'm burning it to the ground.

 

[Snoots]

NO! Don't burn it too the ground.

First, use air to confirm the evap is clogged. Make certain the orfice tube is installed on the proper direction.

yevgenievich put up some great info in post #10. Make sure it holds a vacuum overnight before you try to charge it.

Don't get too frustrated. You're not running into anything that no one else hasn't run into.

 

[DBarre]

There was a bunch of crap in the orifice when I replaced it. I'm sure that's not good. I did install it in the correct direction (just double checked a video).

When charging, the low pressure was around 30 psi and the high was approaching 300 psi. The high was too high and low was still low for about 80 degree ambient. That tells me there is a blockage of some sort. The tube around the orifice was getting cold but the evaporator exit was just ambient temp. I believe the evaporator is the problem because it's the only original part left in the system. I did blow through it before and it seemed fine, but it could be a partial clog with a path for air to still travel through.

 

[bucket]

There was a bunch of crap in the orifice when I replaced it. I'm sure that's not good. I did install it in the correct direction (just double checked a video).

When charging, the low pressure was around 30 psi and the high was approaching 300 psi. The high was too high and low was still low for about 80 degree ambient. That tells me there is a blockage of some sort. The tube around the orifice was getting cold but the evaporator exit was just ambient temp. I believe the evaporator is the problem because it's the only original part left in the system. I did blow through it before and it seemed fine, but it could be a partial clog with a path for air to still travel through.

Lack of airflow through the condenser will cause excessive pressure on the high side of the system. Make sure the clutch fan is moving a significant amount of air at idle, with the AC on.

 

[DBarre]

Thank y'all for the advice! I got it charged and cooling now. In approximately 85 degree ambient, the pressures were 55 psi and 255 psi with about 3 cans of 134a. In the end I ended up replacing every component in the system: New condenser, orifice, drier, compressor, oil, 134a, and belt tensioned just right. I probably still need to do some tweaking to a few things on the truck, but it works for now.

I did notice that it likes to cool much better on the highway, so using the Ford blue orifice would probably help a lot in the city. It's neat to see the principles of thermodynamics in action!