I've been trying to do a boost leak test on my Sapph 4x4 by pressurizing the inlet of the turbo, but it is immediately letting air out of the dump valve. Is this because there is no pressure on the inlet manifold yet because the throttle is closed, so the dump valve sees no pressure yet on the pilot port? Should I do the test with the throttle fully open? Or is the dump valve just not good?

 

 

Thanks, I will check what's wrong with the dump valve in that case.

 

 

 

Charge the system using a smoke machine. It'll be very obvious where your leak is when you see the smoke coming out...