Effective diagnostic tool for determining whether faults are due to the turbo system, or simple air leaks. Simply pressurise using shop air.
The maximum pressure in most turbo systems is approximately 15 PSI - 25 PSI. When connecting the airline to these test caps, always regulate air pressure in the test to 25 PSI maximum. Over pressurisation will damage system components.
A graduated approach to leak testing is recommended. Start with 5 PSI to find large leaks, and progressively increase in 5 PSI increments.