F 550 4WD Super Duty V8-6.0L DSL Turbo VIN P (2003)
Compression Check: Testing and Inspection
Special Tool
Compression Test
1. Make sure the oil in the crankcase is the correct viscosity and at the correct level.
2. Operate the engine until it is at normal operating temperature. Turn the ignition switch to the OFF position.
3. NOTE: Failure to remove all the glow plugs may result in inconsistent test results. Remove the glow plugs. See: Powertrain Management/Glow
Plug System
4. NOTE: The battery charger must be left connected during the compression test and disconnected when the test is complete.
Connect a battery charger to the battery.
5. NOTE: It may be necessary to install a commercially available adapter fitting to connect the Crankcase Pressure Test Adapter to the commercially
available diesel compression gauge.
Install the Crankcase Pressure Test Adapter and a commercially available diesel engine compression gauge.
6. Install an auxiliary starter switch to the starting circuit. With the ignition switch in the OFF position, crank the engine a consistent number of
strokes (minimum of 2 compression strokes to 12 compression strokes). Record the readings.
7. Repeat the test on each cylinder, cranking the engine the same number of compression strokes, record the readings. Compare the readings of the 8
cylinders. There must be no more than a 25% difference between the readings.
8. Investigate and repair any cylinder(s) that are outside of the 25% range.
9. Install the glow plugs. See: Powertrain Management/Glow Plug System
