Automotive Air Conditioning Information Forum (Archives)

Cussboy on Sun October 12, 2014 6:20 PM

Year: 1988
Make: Mazda
Model: B2200 truck
Engine Size: 2200
Refrigerant Type: R-12

About 4 weeks ago B2200 AC went out today !!!! With the fall arriving, this might not seem like the end of the world, but remember this is Phoenix. On the way to work (yes, we run the AC at 7:15am here, need to), about 3 miles in the truck squealed and almost stalled out. I turned off the AC push-in switch and pulled over, opened hood, saw some smoke coming out near front of compressor. I pushed the AC switch in, but compressor did not engage/turn (just the pulley remained turning). The compressor was completely seized; there had been no decrease in AC performance until the moment it happened.

Tim at AMA (this site sponsor) ordered for me a brand-new Sanden 708 Model 7225. Yesterday I did the replacement, new drier, flushed backward with solvent from drier all the way back, removed solvent traces, etc.

The new compressor contained only about 1/2 oz. of 500W mineral oil. The seized compressor didn't contain a drop of oil, and neither did the old drier. I added 2 ounces oil to the drier, and 4 ounces to the compressor. After mounting, I rotated the compressor about 10 times to move the oil around. System was vacuumed, held vacuum, R-12 added, seems fine.

QUESTION: I recovered essentially the full amount of R-12. So how can a system lose oil over 11 years (when I last installed a rebuilt compressor and had the system open) and yet not lose refrigerant? I didn't add any additional R-12 over those 11 years.

bohica2xo on Sun October 12, 2014 11:01 PM

Leaks are odd things indeed.

How does a compressor suddenly loosen both flare fittings from friday night to monday afternoon? Drove home on friday night with the A/C on, working well. Left work monday night and no A/C. Grab the UV light - and dye everywhere at the back of the SD709. Reach down to the flare nuts, and spun both of them off with my fingers.

You DID put some dye in your system right?

B

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"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest."
~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.

Cussboy on Mon October 13, 2014 8:59 AM

Yes, I did add UV dye. I also leak checked all the drier fittings/connections with bubble solution, as well as the vacuum-hold test.

bohica2xo on Mon October 13, 2014 1:43 PM

Then you are good to go. If the oil does sneak out again, you can find it.

Several ounces of oil over a decade left a mess someplace. Wait a few months, and have a look at night with the UV lamp.

-------------------------
"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest."
~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.