1996 AUDI A4 APB Engine Valve Gear Service Workshop Manual

15-96

Valve seats, reworking (refacing)


Notes:

The valve seats should only be reworked just
enough to produce a good seating pattern.
Calculate the maximum permissible reworking
dimension before reworking.
If the reworking dimension is exceeded, the
function of the hydraulic lifters can no longer be
guaranteed and the cylinder head should be
replaced.

Calculating maximum permissible reworking
dimension

- Insert valve and press firmly against valve
seat.

Note:
If the valve is to be replaced as part of a repair,
use a new valve for the calculation.

- Measure distance between end of valve stem and top surface of
cylinder head (illustration shows a 4-valve head).
-
Calculate maximum permissible reworking dimension from measured
Pa
ge 97 of 99 Valve
gear, servicin
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11/21/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.GE05.15.1

distance and minimum dimension.
Pa
ge 98 of 99 Valve
gear, servicin
g
11/21/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.GE05.15.1

15-97

Minimum dimensions
Outer inlet
valve Center inlet
valve Exhaust
valve
32.2 mm 33.2 mm 33.0 mm
Measured distance minus minimum dimension =
maximum permissible reworking dimension.

Example
Center inlet valve
Measured distance 33.0 mm
Minimum dimension - 32.2
mm
Maximum permissible reworking
dimension = 0.8 mm

Note:
If the measured distance is less than the
minimum dimension, repeat the measurement
with new valves, or replace cylinder head.
Pa
ge 99 of 99 Valve
gear, servicin
g
11/21/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.GE05.15.1