Holds vacuum, but not a charge. Instant dump....

[John]

As stated, the system holds vacuum for a couple of hours. I charged it to 55psi before turning on the compressor and it'll hold. As soon as I engage the compressor, it does an instant dump. I shoot another can while it's running and watch the pressure come up and when I stop charging, it just drops to zero. I've shot dye in the system and can't find a leak. The compressor is clean where you'd normally see evidence of a leaking seal. I bought an electronic sniffer. It shows negative around the condenser(which is new), compressor and all connections, which have new seals. Just for the heck of it, I put the sniffer into my vents. It chirped. Is it possible for the evaporator to have such a massive leak? Why does it only leak when the compressor is running??

2007 Nissan Frontier
2024- new expansion valve, seals, dryer, pressure sensor. Blew 42dgrs
2025- new condenser, new seals. Massive leak

[tbirdtbird]

Evaps are famous for leaks. It leaks when the comp is running because of the increased pressure.

[Cusser]

Evaps are famous for leaks. It leaks when the comp is running because of the increased pressure.

Disclaimer: I'm NOT an AC professional

Wouldn't an evaporator have about 30psi pressure while compressor is engaged and static pressure of maybe 90psi when not engaged???

[tbirdtbird]

Cusser, that makes sense what you said.
After pondering this, I have to wonder if the TXV is stuck open, thus allowing the evap to see high side pressure

[JohnHere]

Seems to me that the leak is somewhere in the (new) condenser, or in one of the joints, because the system didn't have a massive leak last year.