Boost Leak Checker Inside

Be careful not to drill holes too close to the edge.

You need to room for seats, washers, basically good contact area and sealing.....you don't want a leaky leak checker.

$4.99 Threaded Nipple....................Autozone
$1.99 Tire pressure checker gage.....Autozone
$0.89 PVC Plumbing Cap...............Homo Depot