| Special tools and workshop equipment required |
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| Valve seat machining device |
Note | t
| When repairing engines with non-hermetic valves, it is not enough to rework the valve seats, seat the valves or replace both of them. The valve guides must also be checked for wear. This is particularly important on high mileage engines → Chapter. |
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| Valve seats are only to be reworked to the extent required to yield a proper surface. Calculate the maximum permissible reworking dimension before reworking. If reworking dimension is exceeded, proper hydraulic valve lifter operation can no longer be guaranteed, so the cylinder head must be replaced. |
| Calculate the maximum permissable reworking dimension |
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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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