Subaru 2009 IMPREZA Service Manual page 289

5. VALVE SPRING
1) Check the valve springs for damage, free length,
and tension. Replace the valve spring if it is not
within the standard value presented in the table.
2) To measure the squareness of the valve spring,
stand the valve spring on a surface plate and mea-
sure its deflection at the top of the valve spring us-
ing a try square.
Free length mm (in) 55.2 (2.173)
Set
Tension/spring
height
N (kgf, lb)/mm (in)
Lift
Squareness
Cylinder Head
235.3 — 270.7
(24 — 27.6, 52.9 — 60.8)
/45.0 (1.772)
578.9 — 639.9
(59.1 — 65.3, 130.3 — 143.9)
/34.7 (1.366)
2.5°, 2.4 mm (0.094 in) or
less
ME-00283
ME(H4SO)-71
6. INTAKE AND EXHAUST VALVE OIL SEAL
1) For the following, replace the oil seal with a new
part.
See the procedure 2) and subsequent for replace-
ment procedures.
• When the lip is damaged.
• When the spring is out of the specified position.
• When readjusting the surfaces of valve and
valve seat.
• When replacing the valve guide.
2) Place the cylinder head on ST1, and use ST2 to
press-fit the oil seal.
ST1 498267800 CYLINDER HEAD TABLE
ST2 498857100 VALVE OIL SEAL GUIDE
NOTE:
• Apply engine oil to oil seal before press-fitting.
• When press-fitting the oil seal, do not use a ham-
mer to strike in.
• The intake valve oil seals and exhaust valve oil
seals are distinguished by their colors.
Color of rubber part:
Intake [Gray]
Exhaust [Green]
ST2
MECHANICAL
ST1
ME-00284