Servicing valve gear
Reworking valve seats
Special tools, workshop equipment, testers, measuring instruments and auxiliary items required
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◆ Depth gauge
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◆ Valve seat refacing tool
Notes:
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◆ When repairing engines with leaking valves, it is not always sufficient to reface or renew 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 just enough to produce a perfect seating pattern. The maximum permissible reworking dimension must be calculated before work is carried out. If the reworking dimension is exceeded, the function of the hydraulic tappets can no longer be guaranteed and therefore 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 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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