Toyota 4A-FE Repair Manual page 57

..
Squareness
ENGINE MECHANICAL - Cylinder Head (4A-FE)
EM-73
EMO 1 83 EM0635
30°
1.2 - 1.6 mm
EM0185
r
1.2 - 1.6 mm
EMOl 86
EM0988
(b) Check the valve seating position.
Apply a thin coat of prussian blue (or white lead) to
the valve face. Lightly press the valve against the
seat. Do not rotate the valve.
(c) Check the valve face and seat for the following:
• If blue appears 360° around the face, the valve is
concentric. If not, replace the valve.
• If blue appears 360° around the valve seat, the
guide and face are concentric. If not, resurface the
seat.
• Check that the seat contact is in the middle of the
valve face with the following width:
1.2 - 1.6 mm (0.04 7 - 0.063 in.)
If not, correct the valve seats as follows:
(1) If the seating is too high on the valve face, use
30° and 45
°
cutters to correct the seat.
(2) If the seating is too low on the valve face, use
60° and 45 ° cutters to correct the seat.
(d) Hand-lap the valve and valve seat with an abrasive
compound.
(e) After hand-lapping, clean the valve and valve seat.
9. INSPECT VALVE SPRINGS
(a) Using a steel square, measure the squareness of the
valve spring.
Maximum squareness: 2.0 mm (0.075 in.)
If squareness is greater than maximum, replace the valve
spring.