SEAT Workshop Service and Repair Manuals > Leon Mk1 > Power unit | 4-Cylinder injection engine (1.4 l engine) | Engine cylinder head, valve gear

Valve seats: reworking

Special tools and workshop equipment required

t	Depth gauge

t	Valve seat refacing tool

Note

t	When repairing engines with non airtight valves, it is not enough to reface or to replace the valve seats and the valves. The valve guides must also be checked for wear. This is particularly important on high mileage engines → Chapter.

t	The valve seats should only be reworked just enough to produce a good seating pattern. Before refacing, the max. allowable refacing value must be calculated. If the reworking dimension is exceeded, hydraulic valve compensation can no longer be guaranteed and the cylinder head should be renewed.

Calculate the maximum permissible reworking level as follows:

–	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.

–	Measure distance between end of valve stem and upper edge of cylinder head.

–	Calculate maximum permissible reworking dimension from measured distance and minimum dimension.

Minimum levels: intake valve 7.6 mm, exhaust valve 7.6 mm

Measured distance = minus max. permissible machining dimension.

Example:

-	Distance measured Minimum distance	8,0 7,6	mm mm
=	Max. permissible reworking dim. → Note	0,4	mm

¹⁾	The maximum permissible reworking dimension is shown on illustrations as dimension “b” .

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