88 / 1588
49
4 DLT ENGINE
PISTONS AND PISTON RINGS
R
emove piston rings from piston using ring expander.
Refer Figure 77
R
emove carbon deposits from piston.
C
lean piston and piston rings thoroughly.
I
n case cylinder bore taper and ovality is within
specified limit, then same pistons and piston rings
may be reused.
E
xamine pistons for cracks, scoring, other damages,
ring groove wear, piston pin bore wear, spring clip
groove wear/damage etc.
In case of any one piston with any one of this defect,
complete piston set should be replaced.
Examine piston rings for scoring, lateral clearance in
piston ring groove and butt clearance in cylinder bore.
Refer Figures 78 & 79
BUTT CLEARANCE OF PISTON RING SHOULD BE
MEASURED INUNWORN PORTIONOF CYLINDER
BORE.
I
n case of any piston ring with any one of this defect,
complete ring set should be replaced.
W
hen cylinder bores are re-bored or honed, pistons
and rings of appropriate size should be used.
P
iston grade as per size is stamped on piston crown.
I
nstall piston rings in their respective position on piston
using ring expander. Refer Figure 80
S
tagger piston rings gaps such that they are 120
0
apart.
Fig. 78
Fig. 79
Fig. 80
Fig. 77