Recommended Procedure - F-Super Duty/Excursion:
WARNING: This page does not describe the selected car, but rather 9 other vehicles, including the 2004 Ford RV Cutaway, 2004 Ford Pickup, 2004 Ford F550 Super Duty, 2004 Ford F450 Super Duty, and 2004 Ford Excursion. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
Do not plug hole on Crankcase Pressure Test Adapter 303-758.
Make sure the engine is at operating temperature. A cold engine will give higher readings. Remove the ducting to the turbocharger inlet pipe and remove the inlet pipe and elbow that connects to the breather box. Block the outlet at the valve cover with the cap provided in Pressure Test Adapter Kit 014-00761 or equivalent. Install a protective screen over the turbocharger inlet.
Screw the Crankcase Pressure Test Adapter 303-758 in the oil fill cap hole. Plumb to the Magnehelic® gauge in the gauge block. Make sure the Magnehelic® gauge has been zeroed.
Start the engine and operate at 3,000 RPM. Hold for 30 seconds minimum and take a stabilized reading. Do not block the hole at the top of the restrictor tool.