Boost leak

Okay, so car is 2003 vw golf gti 1.8t AUM. I'm having big troubles with finding my boost leak or i believe it is boost leak since car is making high pitch sound when boosting. I sealed the IC pipes going right from turbo and pumped air into it. It held it nicely. Only where it doesn't hold if i put pump into first pipe that goes to turbo outlet and pump into it. I feel to resistances whatsoever. I've figured that there is one smaller hose coming from turbine or shortly after it. Can it cause leak and where even does it end up??