A/C Repairs Question

[AlmosN8kd]

Well, I've had my car apart for the better part of a year now because I've been busy and when I'm not busy I haven't felt like working on it. Anyhow, I did my bearing check from what I suspected as rod-knock last summer and all is well there, I reinstalled the oil pan about a month or two ago. But, since things are apart in the general area, I have a refrigerant leak coming from the connections on my A/C compressor.

So, my suspicion is that the knocking was my A/C compressor eating itself so I am going to replace it being that everything is apart making the job relatively easy (famous last words). Upon my searching, most of the compressor re-manufacturers are saying that they will only provide a warranty if the Accumulator/Dryer and orifice tube are replaced along with the compressor.

My question is, why is this necessary?

I have a basic understanding of how the A/C system works and can do the repairs myself (which probably means I won't get a warranty on the parts regardless) but am unsure of why the other parts need to be replaced as well.

On a separate but related note, I don't know who to trust when it comes to these remaned parts as I've never heard of the companies; Mitsubishi wants close to $800 for a new one which is a bit much IMO. So, looking at aftermarket stuff I have the following to choose from:

Summit has Four Seasons: http://www.summitracing.com/parts/FSS-67485/
Auto Zone has Everco: http://www.autozone.com/autozone/parts/Everco-A-C-Compressor/1994-Mitsubishi-3000GT/_/N-j14fiZ91sgi?counter=0&itemIdentifier=320489_145386_3515_
Napa has TEM: https://www.napaonline.com/Catalog/CatalogItemDetail.aspx?A=TEM254324_0120261240&An=599001+101994+50050+2050001
O'Reilly has Murray: http://www.oreillyauto.com/site/c/detail/MUR0/67485.oap?pt=02645&ppt=C0354
and Advance's website says they don't stock any A/C compressors for the car. Are any of these brands better than the others? Maybe one to avoid? Perhaps another parts source I've overlooked?

[VitaminT]

I believe the receiver has a foam filter of some kind that helps oil the freon. Note 100% sure on that, but when I replaced an evap coil on a 94 accord a long time ago it was suggested to change it and and the expansion valve.

[funinthecav3]

The main reason the manufacturers want you to replace additional parts is because they don't want to risk the possibility of old contaminates(metal shavings from the old compressor for instance) coming dislodged from the other parts of the A/C system and damaging their new compressor.

If your A/C system has been torn down for an extended amount of time the replacement of the dryer is highly recommended anyways. Save yourself the hassle and replace the additional parts.

[J Taylor]

It is recommended to change the drier (accumulator/dessicant bag) anytime the ac is opened up. Orifice tube is usually about $2 so there is no reason to not change it as well.....if the compressor is noisy you will probably find chunks of aluminum in the orifice tube anyway. I've used compressors from autozone, advanced, and o'relly and have not had an issue with any of them. I normally just get whichever is priced the best.
Also, if you're doing it yourself, try to borrow a vacuum pump and vacuum the system down before you charge it......I usually do 45 mins or so. Gets rid of air and any moisture.

Jon

[AlmosN8kd]

Yeah, my neighbor has a vacuum pump and guages I can use; he's loaned them to me before.



Any idea on the one form Summitt? It is priced the best of the ones listed (only one under $400); unless someone has another source for parts, most of mine have dried up.

[CPMaverick]

It's always recommended to change the drier as it dehumidifies the freon and absorbs moisture in the system. once it is 'full' of moisture, it doesn't work properly and water starts to get in the components. If the system is left open for awhile, humidity will kill the drier too.

But the reason they won't warranty the compressor without new parts is because when compressors fail, they often throw metal shavings or other contaminants into the system and then when a new compressor is installed, it gets ruined. The drier is the biggest reservoir and is on the inlet side to the compressor so changing it usually gets most of that out of the system.

Cliffs; it's good to replace the drier but if you just want your compressor to work, you can blow out all the lines and system, add new oil and the compressor and go.

[AlmosN8kd]

No, I'll do the job right and replace the extra parts, I don't like to half-ass things; I just wasn't sure why it was necessary.


Thanks for the info guys, I really appreciate it.