Blowing the Freon out of the high pressure release valve?

AUSTIN2003

MEMBER
2002 CHEVROLET SILVERADO
8.1L
V8
4WD
AUTOMATIC
222,000 MILES

My truck has been blowing the Freon out of the high pressure release valve, everything on the high side is new, compressor replaced twice, condenser is new, dryer is new, all o-rings and lines, pressure switches and orifice tube, it has been taken to 2 shops already and they use the big machines to pull a vacuum and recharge the system, sometimes it’s good for 2 days or a day and sometimes it blows while they’re filling it up, I'm at a loss, any ideas?

1 Reply

KEN L

MASTER CERTIFIED MECHANIC
46,719 POSTS

There is only one reason the high-pressure relief valve pops off, excessive high pressure. Can I ask what the high side pressure was before this happened? It should not be over 300 PSI, this is about when the valve lets go. Also make sure your cooling fan is working. Please go over this video:

https://youtu.be/4EqdrBVb0sY?si=-Og3npCLAyKLG-d2

If the fan clutch needs to be replaced, you might see oil/grease around the input shaft. Here is how to change it out, I would use an OEM unit they work best.

This video will how to r&r the fan clutch

https://youtu.be/PoVQpbkCvtc?si=qwF48CLtQZBPzb7r

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