I know it sounds real dumb, but i had the turbo out on my s5 turbo 2 to replace the gaskets, now it's all back together apart from the vacuum pipe from the dump valve. i just can't find where to connect it back up to?

 

I don't know for sure, but check the FSM.... it should be in there somewhere.

 

It's an aftermarket dump valve, that was on the car when i bought it.
now i don't know where i disconnected it from? where do they usually go?

 

That circuit goes from near the compressor output to the (optional) boost controller to the waste gate (dump valve).

 

found it now! thanks