WÄRTSILÄ VASA 6L32, Instruction Manual

Page: 320 / 394

21.3.2 Maintenance
Normally, the starting air distributor does not need maintenance.
If it has to be opened for control and cleaning, remove the complete
distributor from the engine. Certain pistons can be checked in
situ.
1 Remove the end plate (11).
Loosen all pipes from the
distributor. Remove the fastening screws and lift the distribu-
tor off.
2 Remove the plugs (17)
at which the pistons (15) will
come out forced by the springs (14).
3 Take care not to damage the sliding surfaces of pistons
and liners.
4 In case of a stuck piston, use thread M8
at the end of
the piston to get it out, if necessary.
5 It is recommended not to change the place of the
pistons,
although they are precision machined to be inter-
changeable. Utilize cylinder numbers stamped at the control
air connections.
6 Clean the parts and check for wear.
7 If a liner is worn, press it out.
It may be necessary to heat
the distributor up to about 200°C as Loctite is used for fixation
and sealing.
8 Clean the bore
carefully so that the new liner can be
inserted by hand. Otherwise there is a risk of deformation of
the liner and sticking of the piston.
9 Apply Loctite 242
on the outside surfaces when mounting
the liner. Check that the openings in the liner correspond to
those in the housing.
10 Check that there is no Loctite
on the inside sliding sur-
faces.
11 Renew the O-rings
inside the liners.
12 Apply Molykote Paste G
to the piston sliding surfaces
before reassembly. Wipe off surplus paste. Check that pistons
do not stick.
13 Apply silicon sealant
to both sides of the intermediate
plate (13). Do not use too much as surplus sealant will be forced
into the system when tightening the fastening screws.
14 After mounting the distributor
to the engine but before
connecting the control air pipes and end plate (11), check that
all pistons work satisfactorily, e.g. by connecting compressed
air (working air of 6 bar) to the distributor air inlet and by
turning the crankshaft. It is then possible to see whether the
pistons follow the cam profile.
21 Starting Air System 32-200202-01
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