What you will need to make a boost leak checker:

1. pvc cap (home depo or lowes)
2. coupler to fit the pvc cap/intake side of the turbo (home depo or lowes)
3. valve stem (any auto parts store has them)
4. drill bit small enough for the valve stem to fit tight in the pvc cap (drill in the middle of the cap)
5.Place the tap pvc cap in the coupler and tighten it tight.

CAR install and check:
1.Make sure cyc#1 is in TDC (cyc1 is the closest to the timing belt)
2.Take your intake off the turbo
3.place your Pvc/coupler on the turbo (tighten it down)
4.Hook an air compressor air fitting to the valve stem that was drilled in the pvc cap
5.While you are filling the turbo with air listen for leaks. (water and soap in a squirt bottle works great to spot leaks)
6.Have someone watch the boost gauge to see how much air/psi you are building in the system.

Tester should look like that (coupler and cap depends on your turbo intake size)
vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv vvvvvvvvvvvvvvv

That sums it up I think.Rep?