Toyota 3b Repair Manual page 48

-
rl
lr
I
EM-4O
ENGINE MECHANICAL
-
Cylinder Head
(e)
lf the valve stem tip
is
worn, resurface the tip with
a
grinder or replace the
valve.
NOTICE: Do not grind
off
more than the
minimum
amount.
12.
INSPECT
AND
CLEAN VALVE SEATS
(a)
Using
a
45o carbide cutter, resurface the valve
seats.
Remove
only enough metal to clean the
seats.
(b)
Check
the valve seating position.
Apply a
thin
coat
of
prussian blue (or white
lead) to
the valve face. lnstall the valve. Lightly press the
valve
against the seat. Do not rotate the
valve.
(c)
Check
the valve face and seat for the following:
r
lf
blue appears 36O0 around the face, the valve
is
concentric. lf not, replace the
valve.
o lf
blue
appears
3600 around the valve
seat, the
guide and seat are concentric.
lf
not, resurface the
seat.
.
Check
that the seat contact is on the middle of the
valve face
with the following width:
1.9
-
2.3 mm
(O.O75
-
O.091 in.)
lf not, correct the valve seat
as
follows:
(1)
lf the seating is too high on the valve face,
use
3Oo
and 45o cutters to correct the
seat.
(21
lf seating is too low on the valve face, use
650
and 45o cutters to correct the
seat.
EMO183
EMO184