81 / 1526
52
4 DLT ENGINE
VALVE SEATS OF VALVES
Check valve seat height with respect to cylinder head
mating surface. Replace valve seat inserts if they are
worn out beyond specified limit.
Cut exhaust and inlet valve seats with a 45
0
cutter.
Refer Figures 87 & 88
VALVE SEAT MUST BE ABSOLUTELY FAULTLESS
AND WITHOUT ANY CHATTER MARKS.
I
f necessary, lap valve seats to a smooth and even
finish by using suitable hand pump grinder or a lapping
paste and valve itself.
S
mear valve seat with carbon blue. Install valve in
guide and turn it slowly under axial pressure.
CONTACT LINE ON VALVE SEAT MUST BE
AROUND ENTIRE CIRCUMFERENCE AT EQUAL
WIDTH.
D
istance between narrow diameter of valve face to
contact line should be minimum 0.5 mm. - Refer
Figure 89
C
heck for leakages through valve seat by pouring
kerosene on valve head.Kerosene must not seep past
valve seat.
Fig. 87
Fig. 88
Fig. 89