Avtodizel ???-238??, Operating Instructions Manual, Page: 184 / 254

184
6 Unscrew the cylinder head nuts (fig. 83), observing the se-
quence, by reversing of they tightening (fig. 54). Unscrew
the fastening nuts not less than for three steps:
First step – up to 147…118 N
·
m (15…12 kgf
·
m)
Second step – up to 49…39 N
·
m (5…4 kgf
·
m)
Third step – finally unscrew nuts.
7 Remove the cylinder head from the engine and inspect it
thoroughly.
8 If necessary, cautiously remove the cylinder head gasket.
9 Examine the cylinder liners and blank the cylinder openings
to prevent penetration of dust and dirt.
Fig. 83. Unscrewing cylinder
head nuts
Install the cylinder head on the engine by reversing removal op-
erations. Before installing, wipe the cylinder liner shoulders and
matching surfaces of the cylinder head and cylinder block with clean
rags. The reuse of the cylinder head gasket is permissible with the
same cylinder head only at a constant position of liners in the cylinder
block and at absence of gas permeation signs in a zone of the gas joint.
The reuse of the rubber gasket and seals is permissible at absence of
cracks, damages and hardening. See that the rubber cylinder head gas-
ket and the seals are installed properly. The thread should be oiled with
motor oil.
Tighten the nuts in the increasing order of numbers as shown in
Fig. 54, not less than for three steps:
1-st step - 39…49 Nm (4…5 kgfm);
2-nd step - 118…147 Nm (12…15 kgfm);
3-rd step - 216…235 Nm (22…24 kgfm).