AC Blows Hot

[rajramineni]

I did AC diagnostics using http://www.eclassbenz.com/acdiag and found my ac pressure was 3 bar and i have to recharge it. I bought Arctic Freeze R134a 18oz can with gauge. I recharged it and now the reading says 8 bar. I think thats still low. the air is blowing little colder but not like 55 or 60. its doing 69-70 i guess.

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[AMG10]

First if you need to recharge the a/c you may have a leak somewhere. You can charge it but it will most likely go down again. Go to a A/C shop and have it checked.

[rajramineni]

I have finished recharging and now i am getting the cold air from the vents.

[ashutt]

I am going to do this this weekend also. Was it hard or are there any special tips you can give as a result of your completing this task? Thanks in advance.

[rajramineni]

If you know where the low pressure port is, you are all set to do it yourself.

Prerequisite: Perforrm diagnostics before doing a recharge using http://www.eclassbenz.com/acdiag

record the sensor readings and the above link will tell you if you really need to recharge or if there's something else wrong.

For A/c: its the sensor 7 which has the pressure reading, mine was at 3 when i checked and i understood i was running low on FREON.
Recharging took about like 20 minutes and when i rechecked sensor 7 reading it went to 12. I tried more but it didn't go up ( i got cold air, so i stopped).

Note :Shake that R134a Can every few seconds and check the gauge so you don't overfill.

[ashutt]

I do not see the low side port for recharging. Can you tell me how to locate?

Also, I believe I am at 12 for sensor number 7, which is a little low. Looks like should be between 14 and 16.

How do you know when to stop adding the R134a?

[MarcusF]

I think it depends ‘when’ you are seeing the Freon pressure at 12 . On my car, when the car is started, and the AC is turned on, in park, without touching the gas, I see as high as 15. but it’s 7 while driving, and 11/12 while waiting at lights. On a hot day, my AC blows very cold air.

[ashutt]

Thanks Marcus. Mine was at 12 at idle, in park and not touching the gas. I hear the hissing sound sometimes so I assume it is low.

Can you point me to where the low pressure port is so I can recharge today? Thanks in advance.

[MarcusF]

Unfortunately, I can't get to my repair CDs from where I am.

[ashutt]

Can anyone point me to the location of the low side port for recharging the AC? Thanks in advance.

[rajramineni]

see the attachment pic.

its on the driver side near washer fluid.

[ashutt]

Thank you very much! Did you use the gauge in the car to determine when it was full? At what level would that be- 14 to 16? My bottle has the trigger lever and a gauge but not sure at what point it will be full. Thanks.

[rajramineni]

i did it with Arctic Freeze 134a+ which has gauge. On that if you are in Blue zone under 45 psi, you are okay.

donot over fill. what kind of refrigerent do you have?

I checked in my car, it fluctuates between 11 and 12.

[ashutt]

Arctic Freeze 134a+ with the seperate triger and gauge for filling. Online says between 14-16 is good. Your amount seems low so how do you know that 45psi is to much?