Summer time troubles

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Summer time troubles

Postby Guest » Fri Jun 27, 2003 8:42 am

here is a quick a/c class for everyone--I am sure John (JCZ26) will correct any errors I make.


The are quite a few parts to an a/c system but it is fairly simple.

The a/c compressor--it is more or less a refrigerant pump --it takes high pressure refrigerant from the condensor and compresses it, and pumps it out as a low pressure refrigerant and sends it out to the accumulator/reciever drier.

Accumulator--it accumlates and dries refrigerant (removes moisture) and it passes on to the evaporator

Orfice tube---it is an inline filter that is contained inside one of the lowside lines usually around the accumulator or condensor. it not only filters the refrigerant but helps it to go from a liquid back to a gas.

Evaporator---this part (located in the dash with the heater core) has refrigerant passing through it causing it to cool down--the blower motor pushes air across the evaporator cooling the air and then forwards it through the duct works and out the events.
this action turns the refrigerant into a high pressure gas by warming it.

lastly we have the condensor which does just that--takes the high pressure gas and cools it by air flowing across it--the condensor is in front of the rad--then the refrigernat goes back to the compressor and it begins again.


normally when the car is low on refrigerant the compressor will suck the system down until the pressure drops too low, and the low pressure switch will shut the compressor off to protect it. IF there is a restriction in the system, or the cooling fan is not working and the pressure gets too high, the high pressure switch will shut down the compressor. There is also a fan pressure switch on the Berettas which turns on the cooling fan when it senses an increase in the the pressure in the a/c system--

hopefully this will help for those trying to understand hwo the a/c system works--feel free to add or correct anything I may have butchered.  :)







Guest

Summer time troubles

Postby Guest » Sat Jun 28, 2003 2:12 am

yeah, thats right, but an added note, when dealing with the "high side", and the condenser, the condenser is  cooling the gas prior to it going into the compressor.



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Ne14a6tee9
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Summer time troubles

Postby Ne14a6tee9 » Mon Jun 30, 2003 7:19 am

I actually understand it now! Thanks Chris.  :D

Wanna fix mine?  :p


-Chris
‘90 Teal Indy 5 speed :Yahoo!:
'17 HRV EX

Guest

Summer time troubles

Postby Guest » Mon Jun 30, 2003 9:50 am

Quote (Ne14a6tee9 @ June 30 2003,05:19)
I actually understand it now! Thanks Chris.  :D

Wanna fix mine?  :p

what is it doing?

You bring it by and I will fix it  :p



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Ne14a6tee9
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Summer time troubles

Postby Ne14a6tee9 » Mon Jun 30, 2003 11:06 am

The clutch was making a grinding sound and there was metal shavings all over the place so we replaced the clutch and then the compressor stopped working...too bad I didnt know more about the whole system and could fix it myself.

I can get a new compressor from GM for $285 but what else would need to replaced?  ???


-Chris
‘90 Teal Indy 5 speed :Yahoo!:
'17 HRV EX

Guest

Summer time troubles

Postby Guest » Mon Jun 30, 2003 4:07 pm

the accumulator, the orfice tube--then have the system flushed--in other words grab a can of brake clean and disconnect all the lines at their fittings--spray the brake clean into them until it comes out clean the other end of the line, replace the o rings/seals for each line, let the brake clean evaporate, reassemble it, and have it evacuated and recharged---it iwll blow ice cold--the reason behind flushing the system out with brake clean is to remove any metal particles that may damage the new compressor. Be sure to drain the old compressor of the oil, and put the same amount of fresh oil into the new compressor/same with the accumlator--refrigerant oil that is--not motor oil  :p






Guest

Summer time troubles

Postby Guest » Thu Sep 25, 2003 5:50 pm

For anyone getting thier A/C recharged and it's the older R-12 system, ask for "406-A" refrigerant. It may not be easy to find but it's the bomb. From what I hear a lot of places just put 134-A. Theres nothing wrong with that but 406 is waaaaay colder. If your system is 134, you'll have to go with that.



Guest

Summer time troubles

Postby Guest » Tue Jun 07, 2005 6:51 pm

How do I know if my system is R-12??  I have a '94 Z26.  I'm interested as mine needs to be recharged.



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Jeff P
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Summer time troubles

Postby Jeff P » Fri Jun 10, 2005 1:40 am

Look at the header panel cover - that's the cover that goes over your headlights and grille.  There should be a sticker on there that says if you have R-12 or R-134a.  I'd tell you which one you have, but I don't remember when they switched over :)


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Summer time troubles

Postby gypsy » Fri Jun 10, 2005 5:47 pm

I have an older beretta (88) and  I don't have A/C because of an accident that happended before I bought the car. so Im missing parts. I was told it was not worth replacing because the age of the car. Could parts off a newer beretta work? I have the 2.8 in my car. Any suggestions???? ???


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1988GTU
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Summer time troubles

Postby 1988GTU » Sat Jun 11, 2005 12:33 am

What parts are you looking for?


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gypsy
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Summer time troubles

Postby gypsy » Sat Jun 11, 2005 11:34 pm

I pretty much think Im going to need every thing. I was mangled when i got the car.


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Summer time troubles

Postby yellow3800 » Wed Jul 06, 2005 10:58 am

I wonder if 406-A is the same thing as FREEZE 12.  Freeze 12 is what I have in my '88 car [the lemon] and I swear I can push below freezing [30F deg] on the highway.  This is according to a thermometer in the put in a vent.  I turned it off when it got near that temp, and tried not to let it get below freezing again.  

Freeze 12 is $12 a can, no license needed, etc.



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Jeff P
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Summer time troubles

Postby Jeff P » Wed Jul 06, 2005 4:53 pm

Where'd you get the Freeze 12, Andy?


-Jeff P.
Black '88 Beretta GT
Spice Red '06 GTO

Previously Owned:
'89 GT, '91 GT, '92 GTZ (12.95@105 mph), '01 Bonneville SSEi

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Summer time troubles

Postby rweatherford » Wed Jul 06, 2005 11:16 pm

How do you guys get these things so screwed up.....

Compressor take the cool low pressure gas and makes it high pressure, then the condensor takes the excess heat out of the gas (now liquid) using the outside air (fan) and passes the liquid through the accululator/filter/dryer and then it goes through the expansion valve.  When the high pressure liquid squeezes through the small valve it expands rapidly into a low pressure area.  This is where all the cooling potential is.  This area is commonly known as the evaporator.  Then after the gas is heated some (by cooling the hot air in the car, which cools the cabin air and makes cabin colder) the now expanded and somewhat warmer gas goes back to the compressor to be compressed again into a liquid.

This is a VERY simple but accurate discription of the flow path, unlike the first post.  Why would a compressor make a high pressure into a lower pressure?  Then what would you do with it and how could it make anything colder???  Basic gas laws phrohibit such actions.  :;):

Read this if you have more questions.  It covers the basics fairly well.

http://home.howstuffworks.com/ac.htm






Rex Weatherford
92 Beretta GTZ Quad4 Turbo / 5-speed (sold)
Best 1/4 ET =  13.523 @ 105.16 mph

07 Mazda 5 Black on Black (it's slow)



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