Ok, when I bought the car the a/c didnt work, had the day off today and decided to fill it and try to find the leak. Well its hissing horribly in the black box on the passenger side firewall, I forget what that things called but I had to replace it on my s10 last year and it was a pain in the ***, wondering if its the same deal here. And how else do you guys find leaks that you cant hear? Dye? Thanks

 

There are some o-ring seals and such at the expansion valve (#22 ). That might be your problem.

 

if it;s not the 0 rings at the H valve then the only other thing that it could be is a hole in the evaporator core. you can use a full charge and a spray bottole with soap and water and look for bubbles

 

it didnt seem like it was coming from that expansion shoebox, it seemed like it was coming out lower like from under the black box sort of