Piston Protrusion Check

For information on Ford Color Coded Illustrations refer to OEM COLOR CODING

Special Tool(s) / General Equipment

Dial Indicator

Check

Verify that the cylinder block deck surface and the pistons are clean.
The piston protrusion is measured in-line front and rear avoiding raised or etched marking.

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NOTE: Use a commercially available deck bridge such as the Proform® 66797 Magnetic Deck Bridge or equivalent.
- Using the dial indicator and a commercially available deck bridge, position at one of the points on the cylinder block deck surface. Use the General Equipment: Dial Indicator
- Zero the dial indictor on the cylinder block deck surface.
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NOTE: Only rotate the crankshaft clockwise.

NOTE: The piston must remain at TDC or an inconsistent reading will result.
- Position the dial indicator and a commercially available deck bridge, over the piston. Use the General Equipment: Dial Indicator
- Rotate the crankshaft until the piston is at TDC. Use the General Equipment: Dial Indicator
- Record the reading.
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- Move the dial indicator and the commercially available deck bridge, on the cylinder block deck surface at the opposite position. Use the General Equipment: Dial Indicator
- Zero the dial indictor on the cylinder block deck surface.
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- Move the dial indicator and the commercially available deck bridge, onto the piston at the opposite position. Use the General Equipment: Dial Indicator
- Record the reading.
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Average the readings and record.
Repeat on the remaining pistons.
Determine the cylinder head gasket thickness. Refer to appropriate service information. .