seat Workshop Repair Guides

SEAT Workshop Service and Repair Manuals

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Leon Mk2

Reworking valve seats
Reworking valve seats
Special tools and workshop equipment required
t  Depth gauge
t  Valve seat grinder
  Note!
t  When repairing engines with leaky valves, it is not enough to simply re-cut or renew the valve seats and valves. The valve guide wear must also be checked, especially with engines that have covered a large distance.
t  Re-cut the valve seats just to the point where a perfect contact is achieved. Before re-cutting, the maximum allowable re-cut dimension must be calculated. If the re-cut dimension is surpassed, the hydraulic compensation function of the valve play will not be ensured, and the cylinder head must be renewed.
The max. permissible reworking dimension is calculated as follows:
–  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.
   
–  Measure distance -a- between end of valve stem and upper edge of cylinder head.
–  Calculate max. permissible reworking dimension from measured distance -a- and minimum dimension.
Minimum dimension:
   Inlet valve 35.8 mm
   Exhaust valve 36.1 mm
Measured distance minus minimum dimension = max. permissible reworking dimension.
Example:
  V15-0640

-		Measured distance
Minimum dimension		36.5
35.8		mm
mm
=max. perm. rework dimension0.7mm

   
Reworking inlet valve seat
a - Ø 35.7 mm
b - 1.6 mm
45° - Valve seat angle
  Note!
The 30 ° lower valve seat chamfer is necessary to ensure that the inlet channel flow characteristics are maintained.
  V15-0863
Reworking exhaust valve seat
a - Ø 31.4 mm
b - 2.7 mm
45° - Valve seat angle
  V15-0864

Checking valve guides > < Servicing valve gear