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pressure checking system

PTpia on Fri July 22, 2011 11:40 AM User is offline

Year: 2001
Make: Chrysler
Model: PT Cruiser
Engine Size: 2.4
Refrigerant Type: R134A
Country of Origin: United States

As a follow-up to my previous post, I'm still unable to find the refrigerant leak on my wife's PT Cruiser. I was thinking about using compressed air and pressurizing the entire system (starting at the ports) and while it was being pressurized, look and listen for leaks. Good idea? Bad idea? What would be any problems doing this? If done, what would be about the pressure I should use that would show leaks easily but not destroy anything in the system?
Thanks again in advance.

bohica2xo on Fri July 22, 2011 12:07 PM User is offline

Since the system is more or less functional, use 134a to pressurize it. Get the system fully charged, then park it in the sun.

Use a plastic bag or shower cap over the drive end of the compressor, and roll the windows up on the car. Wait an hour or two. Grab your sniffer, and open the car door slowly. Put the sniffer down the vent closest to the evaporator.

if you get no hits in the interior vents, lift the hood & put the sniffer inside the bag on the drive end of the compressor.

Only so many places for that car to leak - and a 3 day leakdown is a good sized leak. Evaporator leaks are worse when the system is not running, and the static pressure is high. Some low side seals do not leak at all when the low side is 30 psi - but leak a lot at 125 static.


"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.

PTpia on Fri July 22, 2011 1:09 PM User is offline

Those are both good ideas and I'll try them this weekend. However, the compressor on this car is not the most accessible, so I don't know how much of the clutch part of it I'll be able to get wrapped, but I'll give it a try. I wasn't aware that evaporators leak more when static than when in use. Maybe I'll pull the carpeting away (again) and cut a small hole at the bottom of the evaporator housing, put the sniffer sensor up inside, then close the doors and let it bake in the sun. The detector has a visual as well as audio notification, so I could look inside to see if it detects anything without opening the doors.

Dougflas on Fri July 22, 2011 3:51 PM User is offline

Instead of making a hole in the evap box (and risk hitting the evap) put the sniffer at the drain tube before you open the doors.

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