Holds vacum , no leaks found , loses charge over night

[MarcuM]

2016 Silverado 5.3 cc 

ive been putting a large can of charge in it every other day 

first I put the sniffer to it and nothing 

I ran dye through it and under Uv light I can’t find any leaks anywhere not even around the condenser 

 , pulled vacum and it set at -20psi for 25mins 

put 40psi of charge in it and got 2 days before it was gone 

works great as long as the charge is above 25psi 

 

I have did this for a solid year now while I worked up north but now I’m transferred to Atlanta so I need my ac 

ive changed the valves out 

truck has 160,000 miles and 6,000 hours on it and I can’t give it up for few days to a shop becuase it’s my life line for work 

 

anyone had this same problem ?

 

[Lsgun1]

If you can't see it then it's likely the evaporator. No real way to tell unless you pull the dash but if it's losing a full charge overnight it should be a big leak.