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Replacing A/C compressor... what to watch out for? by Macarchie
Started on: 07-24-2013 10:06 PM
Replies: 10 (308 views)
Last post by: Macarchie on 07-25-2013 04:28 PM
Macarchie
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Report this Post07-24-2013 10:06 PM Click Here to See the Profile for MacarchieClick Here to Email MacarchieSend a Private Message to MacarchieEdit/Delete MessageReply w/QuoteDirect Link to This Post
Hey people...

I'm replacing the A/C compressor in a '87 with a duke. The instructions for the refurbished unit says to put 1/2 of the lubricating oil in the compressor and turn it by hand several times to lubricate it prior to connecting the hoses. I believe the system has been sealed, so I don't expect any contamination.

Does anybody have a more detailed description of the procedure to get the system back up and running? Are there any problems that I need to watch out for?

thanks, Jimmy

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1987 coupe; Blue; 2.5L; 5spd

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Report this Post07-25-2013 10:23 AM Click Here to See the Profile for 2.5Send a Private Message to 2.5Edit/Delete MessageReply w/QuoteDirect Link to This Post
I dont know alot about Ac, so I had a shop replace and recharge mine. Are you doing it all yourself? Is it R12 or converted to 134?
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TXGOOD
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Report this Post07-25-2013 12:20 PM Click Here to See the Profile for TXGOODClick Here to visit TXGOOD's HomePageSend a Private Message to TXGOODEdit/Delete MessageReply w/QuoteDirect Link to This Post
It`s a good idea to replace the dryer as well. And if you are replacing the compressor then there will be moisture in the lines which will have to have a vacuum pulled on it.
While you have it apart you might as well get some new up to date 134 compatible hose if it still has the original.
I know it seems like a lot but if you look online and here on Pennocks to learn about the AC system it will save you money in the long run.
I didn`t know much but I have a better knowledge now after redoing my AC.
I got tired of spending 500.00 everytime I wanted to get an AC system working only to have it last one season.

[This message has been edited by TXGOOD (edited 07-25-2013).]

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masospaghetti
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Report this Post07-25-2013 12:23 PM Click Here to See the Profile for masospaghettiClick Here to Email masospaghettiSend a Private Message to masospaghettiEdit/Delete MessageReply w/QuoteDirect Link to This Post
You don't need to replace the hoses. It was thought originally that R-134a would leak out of R12 hoses. In service, the old R12 hoses become impregnated with mineral oil and prevent the R134a from escaping.

You DO, however, need to add some oil to the compressor (like you already said), buy a new accumulator and orifice tube, add the other half of the oil to the accumulator. Replace both the accumulator and orifice tube - the tube is really cheap, like $2 and is cheap insurance. The accumulator serves as a system dryer and pulls moisture out that otherwise harms the system and over time, becomes saturated with moisture.
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TXGOOD
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Report this Post07-25-2013 12:27 PM Click Here to See the Profile for TXGOODClick Here to visit TXGOOD's HomePageSend a Private Message to TXGOODEdit/Delete MessageReply w/QuoteDirect Link to This Post
I only replace my hoses because my system had the "black death" and I read where it`s not a good idea to try to clean out the muffler.
And, to get all of the hoses done was 200.00
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masospaghetti
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Report this Post07-25-2013 12:40 PM Click Here to See the Profile for masospaghettiClick Here to Email masospaghettiSend a Private Message to masospaghettiEdit/Delete MessageReply w/QuoteDirect Link to This Post
True, if there was mechanical compressor failure then your hoses could be full of debris. Then it would make sense to replace the hoses.
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Marvin McInnis
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Report this Post07-25-2013 12:55 PM Click Here to See the Profile for Marvin McInnisClick Here to visit Marvin McInnis's HomePageSend a Private Message to Marvin McInnisEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Macarchie:

The instructions for the refurbished unit says to put 1/2 of the lubricating oil in the compressor and turn it by hand several times to lubricate it prior to connecting the hoses.



The procedure per GM is to drain as much lubricant out of the old compressor into a measuring container, and then add that amount plus one ounce to the new compressor. This assumes that you are not changing refrigerant type (R-12 vs. R-134a) or lubricant type (mineral oil vs. PAG vs. ester oil).


 
quote
Originally posted by masospaghetti:

You don't need to replace the hoses. It was thought originally that R-134a would leak out of R12 hoses. In service, the old R12 hoses become impregnated with mineral oil and prevent the R134a from escaping.



Correct, per both GM and the EPA. Plus, I've never seen a Fiero that didn't already have barrier-type refrigerant hoses installed as OEM equipment.




 
quote

You DO, however, need to add some oil to the compressor (like you already said), buy a new accumulator and orifice tube, add the other half of the oil to the accumulator. Replace both the accumulator and orifice tube - the tube is really cheap, like $2 and is cheap insurance. The accumulator serves as a system dryer and pulls moisture out that otherwise harms the system and over time, becomes saturated with moisture.



Agreed. The accumulator should be replaced any time the refrigerant system has been open to the air for more than a few minutes. The warranties on most new or rebuilt compressors are void if the orifice tube and accumulator aren't replaced at the same time as the compressor.

[This message has been edited by Marvin McInnis (edited 07-25-2013).]

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30+mpg
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Report this Post07-25-2013 01:28 PM Click Here to See the Profile for 30+mpgClick Here to Email 30+mpgSend a Private Message to 30+mpgEdit/Delete MessageReply w/QuoteDirect Link to This Post
Replace the orifice tube in the coupling in the front trunk.

If its screen is clogged with black crud, a line flush is needed.
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Report this Post07-25-2013 02:55 PM Click Here to See the Profile for TXGOODClick Here to visit TXGOOD's HomePageSend a Private Message to TXGOODEdit/Delete MessageReply w/QuoteDirect Link to This Post
Because I had a lot of crud that gummed up the oriface tube a couple of times even though I flushed the system out I ended up installing one of these.

http://autoacrepairs.com/ac_in_line_filter.htm

I think mine will need a new compressor eventually because mine whines pretty good, has from day one.
It also doesn`t cool as well at idle but when running down the road it will freeze ya out of there.

[This message has been edited by TXGOOD (edited 07-25-2013).]

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Report this Post07-25-2013 03:33 PM Click Here to See the Profile for TopNotchClick Here to visit TopNotch's HomePageSend a Private Message to TopNotchEdit/Delete MessageReply w/QuoteDirect Link to This Post
Since you have an 87 duke, you have a V5 compressor. That compressor model uses a control valve that can be changed for different kinds of refrigerant. Usually, remanned V5 compressors come with the valve for R12, so you have to replace it with a valve for R134. You can get one here.
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Macarchie
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Report this Post07-25-2013 04:28 PM Click Here to See the Profile for MacarchieClick Here to Email MacarchieSend a Private Message to MacarchieEdit/Delete MessageReply w/QuoteDirect Link to This Post

Great! Thanks for all the good info.

Before he died, my dad purchased a 20# bottle of R-12 which I still have. I have a friend who is an HVAC guy and he will vacuum out and charge up the system when I finish putting it back together. I think the hoses have been replaced because they have the bubble-style crimping. I'll pick up a new dryer and check the expansion valve for the black death residue.

I am also replacing the engine mounts, oil pan gasket, exhaust manifold, serpentine belt and radiator hoses.

Planning to add the oil and hand-turning the compressor. Then replace the dryer and check the screen. Draw a vacuum and check for leaks. If no leaks, we'll add the freon. Am I forgetting anything?

Looking forward to getting the A/C working.

thanks again, Jimmy

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1987 coupe; Blue; 2.5L; 5spd

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