Beetle L4-1.9L DSL Turbo (ALH) (1998)
Valve Seat: Service and Repair
Valve seats, reworking
Special tools and equipment
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Depth gauge
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Valve seat refacing tool
Note:
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When repairing engines with leaking valves, it is not always sufficient to merely or replace valve seats and valves. It is also necessary to check
the valve guides for wear. This is particularly important on high mileage engines.
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The valve seats should only be reworked enough to produce a perfect seating pattern. The maximum permissible reworking dimension must be
calculated before reworking starts. If this dimension is exceeded, the hydraulic lifter function can no longer be guaranteed and the cylinder
head should be replaced.
Maximum permissible reworking dimension, calculating:
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Insert valve and press firmly against seat.
Note: If the valve will be replaced as part of a repair, use the new valve for the calculation.
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Measure distance -a- between end of valve stem and upper edge of cylinder head.
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Calculate maximum permissible reworking dimension from measured distance -a- and minimum dimension.
Minimum dimension:
Intake valve 35.8 mm
Exhaust valve 36.1 mm
Measured distance minus minimum dimension = Maximum permissible reworking dimension.
Example: