My truck is having boost problems. As I accelerate my boost only tops out at about 14psi and actually starts dropping after about 2000 rpm. I thought maybe I had a boost leak somewhere but I put 10lbs to the system with an air compressor and couldnt find any. I could hear some air entering the engine and could feel a little coming out the blow by tube and the oil filler cap. Any ideas? Thanks in advance.

 

You should be able to apply pressure (I would do 25psi) and it hold, if not then you have a leak... Bar the engine over until all the valves are closed or it goes by the intake valves...