A/C always losses pressure
 

Ok people I am stumped I have 06 mega cab 5.9 and I have had nothing but problems with the a/c blowing hot. I have had the thing fixed by the dealer about 10 times and know they can't find a leak. When every I decide to take a trip from home to the mountains it seem to lose refrigerant. I live at seals so in the desert. And the highest is about 8000ft is were I go. I last filled a t in July and until the other day when I went to the mountains it was fine. Help

if they have done it that many times i would have the evaporator replaced thats the only place that is difficult to check for leaks. Have they injected DYE in the system ? if not that would be the next move. Have them inject dye and then check at night the condensate that drips out with a UV light if the water glows at night then thats your problem

Agree with the dye- I hope the dealer hasn't continued to charge you- I would replace the dryer and orfice tube. Also check the line that feeds the dryer. Mine Was rubbing below the batt on the passenger side and it wore a hole through it causing a leak.

They did replace the evaporator that was 1500.00 but still no luck I believe there is dye in the system the also put new compressors dryers orfice tube the only thing left is the condenser. I am going to look by the battery .:argh:

Pressure relief valve on compressor will vent IF you don't have enough air flowing thru condenser "Traffic" Sitting Once it vents it usually will vent easier and easier Hi altitude will cause venting also because of that!

I think that's were it's coming from I seen it happen when the compressor came but how do I fix that.

replace it and then put a switch controlled fan "Pusher" on the condenser slim one fits!

Done this - get a spal slim puller fan 2" anything larger and it won't fit without bending the hood latch- fan, wiring harness, and mounting hardware can be had for $75 from Amazon. I wired this to a relay on the passenger side battery that gets its signal from the compressor- when my compressor is engaged then the fan is running- I didn't want another switch in the cab-it's not really noticeable over the fan clutch when at idle unless you are right in front of it.

Thanks that's what I going to do. Do you know were I can buy that relief valve.

I think he was referring to the entire compressor- I replaced my compressor and my new one did it a few times before adding the slim fan and new fan clutch. It has not done it since- I would try the fan and if it continues then replace the compressor at that point. During the ac repairs has the system been under vacuum all the time/done by the shop? Is your fan clutch engaging properly?