01 Gt won’t hold Freon

I have a 2001 mustang gt that while trying to add Freon it will get cold thru the vents for about 20 seconds then the compressor kicks out the Freon out of relief valve to where it is hot again. I got it to where it was cold and took the Freon off and it was cold for about 3 mins idling then compressor kicked Freon out again out of relief valve. I’ve changed liquid line with orfice tube. Pressure relieve valve on compressor, high pressure discharge hose, accumulator, and condenser has been changed as well. Have any of you all had a problem like/or similar to this ? Thanks!

tsemmett said:

What do your manifold pressures look like? Are you vacuuming the system before charging? Did anyone put anything other than refrigerant and oil in the system? Is there a correct amount of oil?

You likely have too much of something that can't be compressed, causing the pressure to rise too high. I've done this in a system where I flushed it, and didn't get all the flush liquid out (I was lazy and stupid on that one, but sometimes you have to learn the hardway). Too much oil could also do it though.

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tsemmett said:

What do your manifold pressures look like? Are you vacuuming the system before charging? Did anyone put anything other than refrigerant and oil in the system? Is there a correct amount of oil?

You likely have too much of something that can't be compressed, causing the pressure to rise too high. I've done this in a system where I flushed it, and didn't get all the flush liquid out (I was lazy and stupid on that one, but sometimes you have to learn the hardway). Too much oil could also do it though.

Click to expand...

Thanks for the reply! I replaced the switch on the high pressure discharge hose and seems to be working and blowing cold for now. When I unplugged switch I noticed it had corrosion on it and wasn’t pressing down all the way on the Schrader valve. Car was a water car I bought thru Copart and guessing that sensor nose dived into the water. Again thanks!