500SEC (140.070) V8-5.0L (119.970) (1993)
Procedures
1. Clean valves and conduct a visual inspection.
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Valves with scorched valve disc, insufficient height (h) of valve disc or with worn or scared valve stem should be replaced.
2. Measure runout at valve stem.
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If a runout of more than 0.03 mm is measured, replace valve.
3. Machine valve seat.
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Pay attention to operating instructions of machining equipment and setting angle (a) 45° + 15'.
CAUTION:
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If conducting facing work on cylinder head and re-setting of valve seats, always replace valves.
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The valve seats of valves as of model designation M119.98x must not be remachined; these should be replaced when performing repairs.
4. Measure runout at valve seat and height (h) of the valve disc.
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If the runout is greater than 0.05 mm or the height (h) is less than the specification in the tables above, replace the valve.