Hi guys i really2 need help here...

I bought this 86 190E 2.3 16 the initial refrigerant was r12 and so i changed it to 134a i also had to change the pipes since i had new fittings for the low and high pressure. everything was going fine until about two weeks after i checked the pressure of the refrigerant and unfortunately it was out the stuff, so the next thing i did was replace the evaporator, i had an aluminium evaporator custom built. everything is now back in its place and it seems that only after 24 hours the refrigerant has leaked out, any idea whats causing it?!?!?! wah.... problem2...
btw, temp here in the Philippines is arond 30C to 35C
really need help