Air conditioning - dealer says replace compressor!

Like I always say, there's a way around everything. Dealers are all about swapping out assemblys and not repairing the smallest part. I'm pretty certain you could do it yourself or replace your compressor with a used one. I would ask for a second opinion if I were you. Either way, the system will need to be evacuated and recharged ($230 or better). I just don't know what I'd do if I were you. When you consider the cost of evacuating and recharging, the compressor replacement = about$520. That's really not that bad. Tough call.

 

The AC experts who have posted on here have made it quite clear that to get an honest deal on AC repair you have to find the rarest of rare specialist who truly understands these systems... Dealers and basic mechanics don't know AC well enough to do the work. Figure out who the very best AC specialist in your area. The ones who know their stuff most often charge less to fix stuff than the people who think the first fix is to replace major components...

 

It appears to be the compressor "shaft" seal. It ised to be an inexpensive repair, when I did them 40 years, ago.

It is basically a spring loaded composite carbon ring.

I don't know if the one on the 207 can be serviced. It's worth investigating.

 

No shaft on the Prius. It is a sealed, 3 phase motor driving a scroll, which runs off of the HV battery. That is why the A/C works with the engine off. If the seal on the compressor unit is faulty, I doubt anyone would take on the task of taking it apart and attempting to reseal it. That would be too much of a risk, as it is not covered in the repair manual.

There are some good shots from PC user Lech Auto A/C:
prius compressor after body shop serviced a/c | PriusChat

It is possible to get pulls from salvage cars.

 

$750 is actually not bad. There is a lot of labor to removing this compressor, especially if you don't have a car lift.

 

Maybe NOT for any mechanic or a "parts thrower," but for a traielectrical mechanical tectian, there is no harm to inspect a part which the dealer is panning to trash, anyway. Even if the gasket might not be available, RTV will do in most cases.

For an experienced technician, removing and reinstalling a compressor is NOT a big deal. I've done hundreds of them. That includes drawing a vacuum and recharging the system.

 

The AC compressor on the Prius is hermetically sealed, with no protruding shafts or other typical problem spots. It could develop a leak through a crack in the case, but that isn't very common or likely. Because of its sealed nature, the compressor either works or you replace it. Spend some time looking for the leak; I doubt it is in the compressor.

Tom

 

They had to fabricate and seal it, didn't they. That means that it can be unsealed.

Anyhing made by man can be taken apart and put back together, again.

How do you think the manufacturer get it that way? If your're experienced, you can do it.

In my 40 years in the aircraft part failure investigations business, I've seen a lot. I've taken apart my share of FAILED "sealed" units.

 

You and I think the same way. I always try to go down to the Lowest Replaceable Component (LRC in the Navy). The rear wheel bearing is a good example; the assy costs $150+ depending on where you get it, you replace it and throw away a good 10 lbs of steel or, the bearing costs $8-15 and you throw away less than a pound of steel. Needless to say, it is much easier and less time consuming to replace the assy.

 

All true, but you miss the point. The point is that normal AC compressors have shaft seals which age and wear. As a natural part of the aging and wearing process, these seals will eventually leak. It's a given.

The hermetically sealed unit in the Prius has no such seals, so leaking is not inevitable in the normal service life of the unit. As I stated in my first post, it can leak, but it isn't common like it is with a normal compressor. Unless the service people can show the leak coming from the compressor, it makes sense to first investigate other more likely areas and not just replace the unit on a whim.

Tom

 

Yup, there are businesses that make a nice living rebuilding sealed "non-repairable" sealed refrigeration units.
http://www.nationalcompressor.com/hermetic.html

 

There is a tubular end seal that bears upon a flat plate between the compressor section and the electric motor section. It bears upon an iron flat plate with pressure apptied upon it with a helical spring. The end of the tublar seal has likely deteriorated and leaking refigerent and oil into the electrical section. The electrical section is not likely sealed to retain refrigerent. The shaft seal is probably a standard Sankyo, Sanden or Nippondenso part for air conditioning compressors. It would be highly unlikely that they would make a special "purpose built" shaft seal, when one that serves the purpose is available "off the shelf." It's like the bearings. They are probably industry metric standard ones.

 

Mike the oil and refrigerant do enter the motor section hence the need for a non conducting oil, the refrigerant is also used to keep the motor windings cool.

 

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If you or Mike have any pictures you can post, please post them.​

 

The refrigerant enters the electrical section during normal operation - no need to wait for a leak. It's designed that way to avoid the seal problem you describe. The down side is that special oil is needed to protect the electrical windings.

The only way a Prius AC compressor leaks is if the case cracks.

Tom

 

Could be a porus aluminum casting.