A/C Problem

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  #1  
Old 08-01-06, 12:19 PM
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Unhappy A/C Problem

My 93 Nissan sentra, has new expansion valve and accumlator. First a/c was not cooling, blowing only hot air. Low pressure gauge was showing over 100 degrees.

Took apart and replaced x-valve and accumlator and flushed system and vaccumed out whole system. The compressor is working and system seems to be circulating.Tried to refil with 134 freon, now will not take it and gauge shows over 100. Tried putting can it warm water and everything. System for some reason will not take the refrigent. Also there are no leaks in system.

Anyone have any ideas what to do to get it to take the freon and blow cool again? Thanks in advance for advice and suggestions...
 
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  #2  
Old 08-01-06, 12:29 PM
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What is the high pressure side reading. If that is fine, and your using the small refridgerant cans, I always just turn them upside for about 5 sec while slowly charging the system, sometimes they are are just a pain to fill at certain points.
 
  #3  
Old 08-01-06, 01:11 PM
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doesnt sound like the compressor is working at all or very little if its running and low side pressure is still 100 psi it isnt flowing wether it be due to the valves in the compressor or it could just be worn out it doesnt sound like it is working the reason for needing a high side pressure reading it will allow you to see the compressor working as you will see the low side drop and the high side increase.
 
  #4  
Old 08-01-06, 02:19 PM
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Originally Posted by nissianck
My 93 Nissan sentra, has new expansion valve and accumlator. First a/c was not cooling, blowing only hot air. Low pressure gauge was showing over 100 degrees.

Took apart and replaced x-valve and accumlator and flushed system and vaccumed out whole system. The compressor is working and system seems to be circulating.Tried to refil with 134 freon, now will not take it and gauge shows over 100. Tried putting can it warm water and everything. System for some reason will not take the refrigent. Also there are no leaks in system.

Anyone have any ideas what to do to get it to take the freon and blow cool again? Thanks in advance for advice and suggestions...
nissianck,
Something isn't right!
You're saying it won't take any refrigerant but you're reading 100 psig on the low side gauge! Unless you didn't pull a vacuum and you've got air in the system that's impossible...... What kind of vacuum pump do you have and did you pull the vacuum from both the low and the high side?

Plus, how do you know you don't have a leak. How did you test for leaks if you don't have any refrigerant in the system?

What about the high side? You didn't mention anything about the high side pressure......What's going on there?

I'd like to help but you're just not giving enough info; or it's the wrong info!
Phil
 
  #5  
Old 08-01-06, 02:42 PM
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Originally Posted by bejay
doesnt sound like the compressor is working at all or very little if its running and low side pressure is still 100 psi it isnt flowing wether it be due to the valves in the compressor or it could just be worn out it doesnt sound like it is working the reason for needing a high side pressure reading it will allow you to see the compressor working as you will see the low side drop and the high side increase.
+1.

niss, you may missed my post on the other thread. Anyway, it's doesn't sound like your compressor engaged at all.
 
  #6  
Old 08-02-06, 12:07 PM
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Originally Posted by bejay
doesnt sound like the compressor is working at all or very little if its running and low side pressure is still 100 psi it isnt flowing wether it be due to the valves in the compressor or it could just be worn out it doesnt sound like it is working the reason for needing a high side pressure reading it will allow you to see the compressor working as you will see the low side drop and the high side increase.
My father said he could not get the high pressure reading...could not find attachment that fit the gauge.

Now the compressor locked up and a/c belt broke...going to replace both and see what happens. Thanks for you info..
 
  #7  
Old 08-02-06, 12:22 PM
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my info is correct...additonal info

Originally Posted by Philossifer
nissianck,
Something isn't right!
You're saying it won't take any refrigerant but you're reading 100 psig on the low side gauge! Unless you didn't pull a vacuum and you've got air in the system that's impossible...... What kind of vacuum pump do you have and did you pull the vacuum from both the low and the high side?

Plus, how do you know you don't have a leak. How did you test for leaks if you don't have any refrigerant in the system?

What about the high side? You didn't mention anything about the high side pressure......What's going on there?

I'd like to help but you're just not giving enough info; or it's the wrong info!
Phil
The infomation I have provided is correct...no need to lie..lol

There was very lil refrigent in the system..it barley took the refrigent is what I was saying...had to turn bottle upside down for a a few seconds and still barely came out!!

Anyways My father could not check the high pressure reading. Said he could not get to it and gauge fitting would not fit.

The compressor was working as far a I know , it was turning..then locked up and a/c belt broke. Now going to replace those in acouple days and see if that works....I will tell my dad we need to get high and low pressures measured at high and low rpm. He used a high power vaccum (bought at tool store espeacially made for 134 system and had it hooked up to his shop air compressor for 30 minutes n both high and low sides. It read 0 air!!!

I checked for leaks by putting soapy water in a bottle and spraying all the connections on the hoses...no bubbles means not leaks!! Thanks for your input.
 
  #8  
Old 08-02-06, 12:29 PM
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thanks for info

Originally Posted by monoky99
What is the high pressure side reading. If that is fine, and your using the small refridgerant cans, I always just turn them upside for about 5 sec while slowly charging the system, sometimes they are are just a pain to fill at certain points.

Thanks we did that...still did not work much...not much came out..
 
  #9  
Old 08-02-06, 12:32 PM
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yeah compressor locked up

Originally Posted by New guy
+1.

niss, you may missed my post on the other thread. Anyway, it's doesn't sound like your compressor engaged at all.

yes I saw it..thanks....yeas compressor was working not for long though and locked up and belt broke. Now to replace those..wooohoooo. I hate a/c syetems.....My dad said this is the first he had problems with chanding over and recharging...
 
  #10  
Old 08-02-06, 12:51 PM
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when you get the compressor changed should use caution when charging with liquid not for sure what type of can you are using or can tap, per example if you use a can tap that punctures the top turning it upside will allow liquid to flow wich can lock up a compressor could even blow it apart if you are adding it very fast, you should just crack the valve open on the manifold guage until the pressure increases about 5 psi if you are charging liquid usually warming the can in hot water will help to get most of the freon out of the can.
also make sure you cooling fan is working when you get it up and going.
 
  #11  
Old 08-02-06, 01:05 PM
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Thumbs up alright thanks for the info

[QUOTE=bejay]when you get the compressor changed should use caution when charging with liquid not for sure what type of can you are using or can tap, per example if you use a can tap that punctures the top turning it upside will allow liquid to flow wich can lock up a compressor could even blow it apart if you are adding it very fast,[QUOTE]

Oh my...don't want that to happen, did not know that!!Thanks very much the very inportant caution infomation!! I wll inform my fathter when we get new compressor. SHould the water be hot or warm.??...I do not want to be wrong and turn out terribly bad and explode or something.

[QUOTE=bejay]you should just crack the valve open on the manifold guage until the pressure increases about 5 psi if you are charging liquid usually warming the can in hot water will help to get most of the freon out of the can.
also make sure you cooling fan is working when you get it up and going.[QUOTE]

AWESOME INPORTANT INFO!! THANKS!!!
 
  #12  
Old 08-02-06, 01:10 PM
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Originally Posted by nissianck
The infomation I have provided is correct...no need to lie..lol
I'm not saying you lied......just doesn't make sense; maybe you're not explaining things the right way.

Originally Posted by nissianck
There was very lil refrigent in the system..it barley took the refrigent is what I was saying...had to turn bottle upside down for a a few seconds and still barely came out!!
That's the part that doesn’t make sense! ! ! ! When you pull a vacuum on the system, and then start charging, a good portion of the refrigerant gets pulled in by the vacuum; you don't even have to run the compressor. If you're using the small cans, you should be able to get at least the first can and maybe part of the second can into the system without ever starting the car!

Originally Posted by nissianck
Anyways My father could not check the high pressure reading. Said he could not get to it and gauge fitting would not fit.
I would have stopped right there! If you don't monitor both the low side and the high side, you can't determine what's wrong!

Originally Posted by nissianck
The compressor was working as far a I know , it was turning..then locked up and a/c belt broke. Now going to replace those in acouple days and see if that works....I will tell my dad we need to get high and low pressures measured at high and low rpm. He used a high power vaccum (bought at tool store espeacially made for 134 system and had it hooked up to his shop air compressor for 30 minutes n both high and low sides. It read 0 air!!!
Two things here:
1) If the compressor locked-up and broke the belt, chances are that compressor seized up. If the compressor seized; you should flush the system or you run the risk of damaging the new compressor.
2) I hate to tell you this, but those shop air compressor powered vacuum pumps are junk. They do not pull a deep enough vacuum to allow any moisture in the system to boil off. The main reason for putting the system into a deep vacuum is to get any moisture in the system to boil and get sucked out of system.

Plus, how did you read "0" air? There is no reading for air! When the system is in a vacuum, and there is no more air or moisture in the system, the low side gauge will drop to about 29.9 in/hg. Also, you need to verify it can hold 29.9 in/hg for about 20 minutes to determine there is no more moisture in the system. When in a vacuum, if there is still moisture in the system, it will boil and cause the vacuum to rise from 29.9 in/hg and run closer to zero. When that happens, you need to continue pulling a vacuum until it holds 29.9 in/hg for about 20 minutes.

In your case, if you pulled a vacuum and your low side guage is still reading "0", then you have air in the system. A lot of air! "0" on the low-side gauge is what the gauge reads when it's not hooked up to the car. “0” is normal atmospheric pressure.

Originally Posted by nissianck
I checked for leaks by putting soapy water in a bottle and spraying all the connections on the hoses...no bubbles means not leaks!! Thanks for your input.
Soap bubbles are okay, but how did you check the evaporator with soap bubbles when it's buried up in the dashboard? If your evap has a leak, you won’t know it unless you use a refrigerant sniffer or a dye!

I wish I could say you are on the right track. But unfortunatly, you're not!
Good luck,
Phil
 
  #13  
Old 08-02-06, 01:17 PM
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warm water is fine all you are doing is warming the can to increase the pressure inside the can as freon pressures vary depending on what temperature they are at you probably wont need to use it on the first can.
 
  #14  
Old 08-02-06, 01:32 PM
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Smile alrighty

Originally Posted by bejay
warm water is fine all you are doing is warming the can to increase the pressure inside the can as freon pressures vary depending on what temperature they are at you probably wont need to use it on the first can.
Alright..cool...thanks again!!!
 
  #15  
Old 08-02-06, 01:46 PM
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Arrow it will all work out for the best...

Originally Posted by Philossifer
I'm not saying you lied......just doesn't make sense; maybe you're not explaining things the right way.


That's the part that doesn’t make sense! ! ! ! When you pull a vacuum on the system, and then start charging, a good portion of the refrigerant gets pulled in by the vacuum; you don't even have to run the compressor. If you're using the small cans, you should be able to get at least the first can and maybe part of the second can into the system without ever starting the car!


I would have stopped right there! If you don't monitor both the low side and the high side, you can't determine what's wrong!


Two things here:
1) If the compressor locked-up and broke the belt, chances are that compressor seized up. If the compressor seized; you should flush the system or you run the risk of damaging the new compressor.
2) I hate to tell you this, but those shop air compressor powered vacuum pumps are junk. They do not pull a deep enough vacuum to allow any moisture in the system to boil off. The main reason for putting the system into a deep vacuum is to get any moisture in the system to boil and get sucked out of system.

Plus, how did you read "0" air? There is no reading for air! When the system is in a vacuum, and there is no more air or moisture in the system, the low side gauge will drop to about 29.9 in/hg. Also, you need to verify it can hold 29.9 in/hg for about 20 minutes to determine there is no more moisture in the system. When in a vacuum, if there is still moisture in the system, it will boil and cause the vacuum to rise from 29.9 in/hg and run closer to zero. When that happens, you need to continue pulling a vacuum until it holds 29.9 in/hg for about 20 minutes.

In your case, if you pulled a vacuum and your low side guage is still reading "0", then you have air in the system. A lot of air! "0" on the low-side gauge is what the gauge reads when it's not hooked up to the car. “0” is normal atmospheric pressure.


Soap bubbles are okay, but how did you check the evaporator with soap bubbles when it's buried up in the dashboard? If your evap has a leak, you won’t know it unless you use a refrigerant sniffer or a dye!

I wish I could say you are on the right track. But unfortunatly, you're not!
Good luck,
Phil

Ok then!! Well hopefully your info will put me on the right track!!

I will let my dad read your info. He is an auto mecanic and has worked on several automobiles and trucks in his years. This is first one he has had problems with!!!!

He has changed and recharged vehciles in the past with no problems!!

We know we will have to flush the system again...




Life is not prefect....nobody is perfect....you live you learn...
 
  #16  
Old 08-02-06, 02:28 PM
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Originally Posted by nissianck
Ok then!! Well hopefully your info will put me on the right track!!

I will let my dad read your info. He is an auto mecanic and has worked on several automobiles and trucks in his years. This is first one he has had problems with!!!!

He has changed and recharged vehciles in the past with no problems!!

We know we will have to flush the system again...
nissianck,
Yeah, that's what makes working Auto A/C interesting! Especially retrofitting from R-12 to R-134a. Some cars are easy to retrofit while others are very finicky.

Sounds like you got a finicky one!
Good luck,
Phil
 
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