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a/c pressure too high -?compressor?

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  #1  
Old 05-13-2008, 09:04 AM
ratwellnc's Avatar
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Default a/c pressure too high -?compressor?

Please help!
Bought '98 Civix EX from coworker - the air conditioner runs a few seconds or minutes and then compressor turns off- sometimes boggs down engine.
I tried adding freon made it worse. Took it to local shade-tree shop they put real guages on it and it appears the pressure is running up to 400 psi and then limit switch causes compressor to kick out. Then recycles.
They said I need a new compressor Plus, Plus.
Wait - it is compressing too well. Seems like a restriction to me.

Any ideas?????
I ws told it had a new a/c compressor but turns out it had a new condensor fan.
Thanks,
Richard
 
  #2  
Old 05-13-2008, 09:09 AM
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Default RE: a/c pressure too high -?compressor?

It sounds like the compressor is overfilled with refrigerant. If the compressor hasn't already been damaged, then maybe you can drain some refrigerant from the system.
 
  #3  
Old 05-13-2008, 09:43 AM
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Default RE: a/c pressure too high -?compressor?

This usually happens because the condenser fan doesn't work. Does the condenser fan work?

Overfilling of course only makes it worse. You need to remove it all and put the proper amount in by weight to be sure of how much you have. Many quick-lube shops have equipment to do this for you though they don't work on other parts of the system.

There's certainly nothing wrong with the compressor. And if you have a restriction, the pressure on the high side will actually be less than normal, unless someone has overfilled it.
 
  #4  
Old 05-13-2008, 10:21 AM
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Default RE: a/c pressure too high -?compressor?


Thanks for the suggestions. The guys at the shop took some freon out and put some back in.
Checked the gauges on both sides -the low side was supposedly ok but the high side would go beserk. They said " We don't know what is going on but a New Compressor should fix it. "
I think maybe / maybe not.
I'm look for some background experience more than their remove/replace system approach.
I can try letting out more Freon but the pressure was supposedly ok, both on the guage from Advance Auto Freon can and the "professional" guages.

I will check the condensor fan - but do not remember it NOT working. And that is what was replaced. Should fan come on immediately when a/c is turned on.
R
 
  #5  
Old 05-13-2008, 10:31 AM
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Default RE: a/c pressure too high -?compressor?

Yes, the fan should come on immediately.

Many Civic systems only hold about 18 oz of refrigerant ("freon") so it is very easy to overcharge. You need to start by taking it ALL out, using a good vacuum pump to get down to a nearly complete vacuum. The vacuum step will ensure that there is no air in the lines, which also causes excessive high side pressure. The exact amount to charge should be on a sticker under the hood.
 
  #6  
Old 05-13-2008, 10:57 AM
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Default RE: a/c pressure too high -?compressor?

Thank you for the quick response.
I went out and checked.
The Condensor Fan does come on immediately when the A/C is turned on.

There is a sticker that calls for R-134a: Max 22.9 oz and Min 21.2 oz with Honda PAG oil

I will look for a place that will vacuum it out and refill with the correct amount. Most non-Honda places will not have Honda PAG is generic PAG ok?

The fellow who worked on it for the previous owner might be questionable and could easily have put in too much.
When it was originally cyling on/off I thought it was an indicator oflow- but the guages said differently.
Thanks again
 
  #7  
Old 05-13-2008, 11:12 AM
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Default RE: a/c pressure too high -?compressor?

Vacuuming out the refrigerant will not remove any oil. (This could be a problem if an excess of oil has been added.) In order to change the oil you have to take the system all apart and flush the oil out of each part. The original oil can last the life of the car unless there has been a severe leak (e.g. crash damage) and the oil blew out.

Have it refilled with plain R-134a only. Do not add more oil.
 
  #8  
Old 05-13-2008, 12:12 PM
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Default RE: a/c pressure too high -?compressor?

Thanks MK378
I am confident that this vehicle has not been in a crash but oil could have been added along with extra freon when they were diagnosing that it needed condensor fan.

I will iget it vacuumed and refilled without any extra oil and see how that works.
 
  #9  
Old 05-14-2008, 01:16 PM
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Default RE: a/c pressure too high -?compressor?

Thanks to all,
I got the Civic back from shop. They evacuated the a/c system said it was almost 1 pound overfilled. They recharged it with the proper amount and said it was cooling ok.
I will try it and see how it does when it really gets hot here. It is only 75 today.
Thanks again
 
  #10  
Old 07-29-2011, 05:25 AM
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Default 2005 Honda Civic LX A/C

I would like to know the A/C low side pressure reading for an 05 Civic and the amount of freon needed to refill the system. Thanks in advance for any info.
 
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