98 K1500 A/C leak diagnosis

[Rollybear1]

I have a 98 K1500 with the 5.7. Last summer (2022) I worked on the A/C and charged it after not working since i bought it. It blew cold, only for the charge to go away after about a week. It short cycled until the compressor never engaged again. Obviously i assumed a leak. Just this last friday I took it up again determined to get a fix going and when i hooked up my gages, there was still about 50 psi static charge. I started leak checking with soapy water and found the compressor was leaking between the segments. Replaced comp, pulled down and recharged it sunday. It blows cold (40), but im still getting a low refrig charge symptom and again its going down almost daily. I put right at 48 oz in it.
what i cant figure out is how it kept a static charge all those months if its got a leak somewhere else. I leak checked the new compressor last night and I dont see anything. Anyone ever seen this? Thanks in advance for any help!

 

[Schurkey]

When the system is off, and if there's any reasonable amount of charge left, the pressure will be related to the temperature.

Therefore, testing pressure with the system "off" is useless.

Apparently, your truck has more than one leak. You may be able to get a refrigerant leak tester from a parts-store "loaner-tool" program. The evaporator, the condenser, the receiver-dryer, the hoses, the service fittings, and EVERY O-ring is suspect until proven good.

If I'm going to work on an A/C system, I just expect to replace EVERY O-ring, and usually the orifice tube, and the receiver/dryer/accumulator. It's a bonus if I don't have to replace the condenser, and a REAL bonus if the evaporator is leak-free.

 

[Rollybear1]

Good advice. Thanks Schurkey!

 

[pressureangle]

Most leaks that are not obvious are the valve cores in the service fittings. Be sure to check that they're snug.

 

[alpinecrick]

Most leaks that are not obvious are the valve cores in the service fittings. Be sure to check that they're snug.

This^^^
It's the first place I look at......