Automotive Air Conditioning Information Forum (Archives)

mitchedo on Mon July 18, 2011 5:48 PM

Year: 2006
Make: Toyota
Model: Sienna
Engine Size: 3.3
Refrigerant Type: R-134

This spring, I noticed some compressor noise, and the A/C would either work or it wouldn't. When it worked, it cooled well. The system totally quit Saturday; the clutch would not engage, but the system seemed to have a full charge. I could still turn the compressor by hand after the clutch shut off.

I checked the pressure switch, and it was working fine -- on at ~100 psi. So I recovered the system and pulled the compressor. The compressor still turns rather easily by hand. The clutch, however, has a gooey, rubbery, sticky substance all over the place, as seen in the photos.

What could cause this? Of course, I'm hoping someone will tell me the clutch just failed and I don't need to disassemble any further to check for compressor bits in the TXV screens.


Here is the face of the clutch on the compressor after removing the outer part.



This is the same thing with the other half of the clutch lying next to it.



Other half of clutch, disassembled.



close-up of disassembled clutch



close up of clutch, disassembled.


-------------------------
Doug
Home of the "Tunex Suburban Disaster"

Edited: Mon July 18, 2011 at 5:50 PM by mitchedo

GM Tech on Mon July 18, 2011 6:20 PM

Clutch was unable to handle the torque transfer to compressor- either clutch was oily/greasy feom leaky shaft seal and slipped due to grease--- or compressor went through a high torque mode and caused clutch to slip---once clutch starts slipping, it melts all the rubber torque cushion elements and clutch is toasted---

Since compressor turns easily, I would opt for scenario number one, your clutch had oil on it, and started slipping when high torque was present---you can try a new clutch, but chance are your shaft seal is the root cause--so I would opt for a new compressor-- clutches usually cost more than half the price of a new pump anyway.....

-------------------------
The number one A/C diagnostic tool there is- is to know how much refrigerant is in the system- this can only be done by recovering and weighing the refrigerant!!
Just a thought.... 65% of A/C failures in my 3200 car diagnostic database (GM vehicles) are due to loss of refrigerant due to a leak......

mitchedo on Mon July 18, 2011 7:05 PM

Quote
Originally posted by: GM Tech
Clutch was unable to handle the torque transfer to compressor- either clutch was oily/greasy feom leaky shaft seal and slipped due to grease--- or compressor went through a high torque mode and caused clutch to slip---once clutch starts slipping, it melts all the rubber torque cushion elements and clutch is toasted---



Since compressor turns easily, I would opt for scenario number one, your clutch had oil on it, and started slipping when high torque was present---you can try a new clutch, but chance are your shaft seal is the root cause--so I would opt for a new compressor-- clutches usually cost more than half the price of a new pump anyway.....

What would cause the high-torque condition? It was mighty hot the week I was in the Ft Worth area - 104-108 degrees. I'm pretty sure both fans were working well. I even borrowed a gauge set from Autozone the day before I left Ft Worth; the high side pressure never got over 350 psi while I was sitting there in 104 degree heat, so it seems both radiator fans were doing their thing. It cooled really well in that heat, though I did notice what I thought was compressor noise when I first started the van. It seemed to go away after a few minutes. I'd been hearing that noise for a couple of weeks, but didn't have time to change the compressor. It hadn't really been hot here at home until the day or two before I left for Ft Worth, but it seemed the AC compressor wasn't staying on long enough.

I have already ordered a compressor and drier from Autozone, would have been here tomorrow if I'd called a couple hours earlier. ...should be here day after tomorrow. I should have ordered from Tim, but I really wasn't sure what to order or what I'd need to take back, so I ordered locally.

I took apart the compressor, and it looks absolutely pristine. The puddles of oil in it are absolutely clean and clear. All five pistons move freely; there is only the smallest of markings on the cylinder walls. I don't know what's normal for 64,000 miles, but this compressor looks really clean. There are absolutely no bits or chunks or grains of any kind in it. The shaft around the seal does look a bit less than shiny clean.

I'm thinking I'll just replace the compressor and drier and hope for the best. The AC cooled great at 108 degrees in Ft Worth the day before it croaked. Getting to the TXV is a nightmare. I'll be sure to look carefully when I put the new drier guts in the condenser.

-------------------------
Doug
Home of the "Tunex Suburban Disaster"

TRB on Mon July 18, 2011 7:43 PM

Quote
Originally posted by: mitchedo
Quote
Originally posted by: GM Tech
I'm thinking I'll just replace the compressor and drier and hope for the best. The AC cooled great at 108 degrees in Ft Worth the day before it croaked. Getting to the TXV is a nightmare. I'll be sure to look carefully when I put the new drier guts in the condenser.

Drier is part of the condenser. So you need to see how the oil looks before just replacing. Either way we at Ackits.com have a low priced import option for this vehicle if interested. Send me an email and I can quote it of. These items are not listed on our main site.



-------------------------
When considering your next auto A/C purchase, please consider the site that supports you: ACkits.com
Contact: ACKits.com