Special tools and workshop equipment required |
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| Valve seat refacing tool |
Note t
| When repairing engines with leaking valves, it is not sufficient to reface or renew valve seats and valves. Particularly on high mileage engines, it is necessary also to check valve guides for wear → Chapter. |
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| Valve seats should be reworked only enough to produce a perfect seating pattern. Before beginning to rework valve seats, calculate the maximum permissible reworking dimensions. If the reworking dimension is exceeded, hydraulic valve compensation can no longer be guaranteed and the cylinder head should be renewed. |
The max. permissible reworking dimension is calculated as follows: |
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| Insert valve and press firmly against valve seat. |
Note If the valve is to be renewed as part of a repair, use a new valve for the calculation. |
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