Automotive Air Conditioning Information Forum (Archives)

Row Z on Mon June 18, 2007 11:39 AM

Year: 2003
Make: Chrysler
Model: PT Cuiser
Engine Size: 2.4
Refrigerant Type: 134A
Ambient Temp: 80
Pressure Low: 40
Pressure High: 50
Country of Origin: United States

MY relief valve has started popping off, pressures are 40 low / 50 high at idle with clutch running. Pressures were taken from the ports that are side by side on right side top of engine compartment. Pressures fluctuate when the condenser fan kicks on. I also see what looks like a high side port down by the compressor, between compressor and condenser (my arms are to fat to get the hose connected down there.)
Seemed like compressor was the problem, so I changed compressor, receiver dryer, liquid line w/ orifice tube, flushed evap condenser and lines.
Pulled a vac, charged it. And.........I still have the same problem, same pressure readings, relief valve popping off.
Any suggestions??
Do I need to get someone with skinny arms to use the other port for correct pressure readings?

Row Z



-------------------------
Row Z

mk378 on Mon June 18, 2007 1:57 PM

You're using the wrong port. If you get connected to the other one you'll probably see 350 or more psi.

Assuming it's not overcharged, it sounds like a fan control problem. The fans should run constant while the car is sitting still with the compressor engaged in hot weather. Probably there is a sensor on the high side that tells the ECM the pressure, then the ECM turns the fans on. If that sensor is bad, the ECM also won't be aware of extremely high pressure. It is supposed to turn the compressor off before the relief valve pops.

Row Z on Mon June 18, 2007 2:52 PM

There is a sensor on the end of the compressor, I'll check it out tonight. Thanks, for the help.

-------------------------
Row Z

Row Z on Mon June 18, 2007 3:05 PM

Dealer tells me the sensor on the end of compressor is the High pressure cut out switch.

-------------------------
Row Z

Chick on Mon June 18, 2007 7:15 PM

Check out this post from almost a year ago and it may shed some light on your pressue readings..Hope this helps.

-------------------------
Chick
Email: Chick

---------------------------------------------

Freedoms just another word for nothing left to lose

Row Z on Tue June 19, 2007 10:29 AM

Hooked up to the hidden service port at the compressor, pressures are good. Changed out the low speed fan relay, and now the fan kicks in when clutch is on. Problem solved.
Looks like a $10 relay was the problem. To bad I blew all that money on Compressor,etc,etc,etc.
Oh well...live and learn.....the wife is happy now that her beloved PT Cruiser has cold AC again.

Anyone have suggestions on a good economically priced vacuum pump? suitable for a DIY'er?

Thanks for the help.

-------------------------
Row Z

Chick on Tue June 19, 2007 11:02 AM

check out these Mastercool vaccum pumps there is one for every price range..

-------------------------
Chick
Email: Chick

---------------------------------------------

Freedoms just another word for nothing left to lose

Dougflas on Thu September 11, 2014 5:01 PM

Quote
Originally posted by: lordsmrfixit
The best vacuum pump is out of an old free fridge.

But you don't have to evacuate the system with 134!

Only with the old R12!
You may follow your own procedures on your own vehicles. You are doing others a disservice by feeding them that poop.
The oil in R134a systems will absorb moisture rather quickly. A refrigerator compressor will not pull the vacuum level to a safe level. And you do need to evacuate a R134a system.

HECAT on Fri September 12, 2014 7:06 AM

Quote
Originally posted by: lordsmrfixit
The best vacuum pump is out of an old free fridge.

But you don't have to evacuate the system with 134!

Only with the old R12!

Welcome Lord Mr. Fixit. This site has a number of very knowledgeable professional and non-professional technicians who volunteer their experience to try and assist the many posters with sound and proven advice. Unfortunately with your very first post, you have chosen to revive a 7 year old post with a 3 line comment; 2 of which are total nonsense. I would suggest you read more in the archives (as you apparently have been doing) to seek more knowledge about this craft. Fell free to ask questions and seek guidance. However, keep in mind that this is not a DIY Hack site and continued spewing of such nonsense will surely and quickly have a Moderator restricting your access privileges.

-------------------------


HECAT: www.hecatinc.com You support the Forum when you consider www.ackits.com for your a/c parts.

FLUSHING TECHNICAL PAPER vs2.pdf 

chris142 on Mon September 22, 2014 10:48 PM

R12 and R134a systems must be vacuumed before being charged if they are opened. R134a is even more particular about air in the system than an r12 system. A little bit of air will skew the pressures.

bohica2xo on Thu September 25, 2014 12:10 AM

Ah, my favorite magic in a can...

"Clown be Gone!"

B.

-------------------------
"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest."
~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.

HECAT on Thu September 25, 2014 6:57 AM

Well I missed his return, and can only gather he did not heed the warning, as the clown be gone. Thanks for taking care of that B.

-------------------------

HECAT: www.hecatinc.com You support the Forum when you consider www.ackits.com for your a/c parts.

FLUSHING TECHNICAL PAPER vs2.pdf