F 550 4WD Super Duty V8-6.4L DSL Turbo (2008)
Piston: Testing and Inspection
Piston Diameter
1. NOTE: When considering installing a new piston, check the cylinder bore out-of-round specifications, cylinder boring may be necessary. Cylinder
bore reconditioning will require oversize service pistons.
Use a 75-100 mm (3-4 inch) micrometer to measure the piston skirt. Verify piston size by measuring the skirt diameter.
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Measure 15.5 mm (0.061 inch) from the bottom, at 90 degrees to the piston pin, at room temperature of 19-21° C (66-70° F).
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Install a new piston if not within specification.
Piston Ring End Gap
Special Tool(s)
1. NOTE: Faulty rings cannot always be detected by visual inspection. Therefore, whenever a piston is removed from a cylinder, install new piston
rings.
Inspect the new piston rings for cleanliness.
2. Before installing new piston rings on the piston, check the gap for each ring.
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Push the piston rings into the cylinder bore. Make sure the piston ring is square with the cylinder wall. An inverted piston head may be used to
push the piston ring to the desired location of the measurement (usually at the top of the piston ring travel).
3. Using the Feeler Gauge, measure the gap between the ends of each piston ring.
4. If the gap does not meet specifications, select another ring or recheck the cylinder bore wear.