Low side AC pressure very high

metalmoto

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AC stopped working on my 04" KJ. Hooked up the gauges, and tried adding some refrigerant. The low side gauge was pegged as high as it will go.
So should I assume the orifice tube is clogged? And replacing it will solve the problem? I have a vacuum pump, and realize it must be vacuumed after replacing the hose/pipe. Should I be worried about the compressor too?
Thanks in advance.
 

Conundrum2006

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What kind of gauge were you getting a reading with, how high was high, and was the compressor running when it read too high.

Not running the low side will sometimes read 100psi as it runs dropping to normal levels. ACs are tricky to diagnose, switches, relays, magnetic clutch, lots of little things can stop it from engaging sometimes getting a shop to diagnose what’s wrong and fixing it yourself may be the way to go. Not that you can’t do it on your own, I do my own car ac work and know what a pain it can be.


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chinkapin

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Had the same issue with my 2002 Liberty. We found that the fan clutch was shot and not cooling engine well enough. Replaced fan clutch and A/C started working without adding any Freon. On a side note the gas mileage also improved greatly. To check the fan clutch try stopping the fan with the motor running. use something soft and be careful!!
 

metalmoto

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Thanks, but my Jeep has electric an electric fan. I tried replacing the pipe with the orifice tube inside it. Thinking perhaps it was clogged. That didn't help. The system seems to hold a vacuum fine. But it still wont seem to take more then a few ounces of refrigerant.
My guess is the compressor is shot. Haven't done anything more with it, since winter came. Now it's spring, and it will soon be getting warmer. So I'll have to figure out whats wrong with it soon...
 

JeepJeepster

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Is the compressor running or no?

what exactly is the pressure on the high and low side with the compressor off? The two should be equal with the compressor off.
 

metalmoto

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Compressor is running. I can get the interior temp down to about 80 degrees, running the engine at 2,000 RPM. When I turn off the engine, the low side reads over 120 PSI, the High side 150. The low side is still very high, with the engine running.
PLEASE HELP! I still have everything hooked up in my driveway. Already added about a can and a half, after vacuum down the system for a hour.
It's 95 degrees here during the day, and I need to drive a hour to work.
Thanks in advance.
 

Myke

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Download the FSM it containts a troubleshooting section for the AC.

What are the pressures while the compressor is running (engine on, clutch engaged)? and what is the outside temp when you took these readings?

Does your compressor cycle a lot? like more than 8 times a minute?
 
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