Perkins New 1000 Series, Руководство по ремонту, Страница: 269 / 290

Workshop Manual, TPD 1350, issue 3 269
23
New 1000 Series
To maintain the brush gear and the
commutator
23-7
S115 starter motors
Inspect the brushes at intervals to ensure that they
are free in their guides and that the wire connections
are free to move. To check this, lift the spring from the
brush and pull carefully on the flexible connections. If
the brush does not move freely, remove it from its
holder and clean the sides with a material which is
damp with gasolene.
Ensure that the brushes are fitted in their original
positions to keep the original wear seat. The brushes
must have good seats which conform to the shape of
the commutator. If the brush seat is not correct, put a
piece of very fine carborundum paper or similar
material tight around the commutator with the rough
face to the outside. With the brush in position, turn the
armature by hand, in the normal direction of rotation,
until the brush has the correct shape. If the brushes
are worn and the springs do not give enough
pressure, they must be renewed. Check the spring
pressure with the hook of a spring balance under the
spring lip. The correct tension is 8,34/11,00 N (30/40
ozf) 0,85/1,13 kgf.
The new brushes must be the exact same grade as
the original brushes. To ensure that correct brushes
are fitted, use only parts from the approved
manufacturer. To remove the brushes, remove the
four setscrews that hold the brushes, one for each
brush. When the new brushes are assembled,
connect carefully the field coil and connector wires,
held by two of the setscrews. Before the brushes are
inserted in their holders, it is advised that the holders
are cleaned with compressed air or with a material
which is damp with gasolene.
The commutator must be completely clean; dirt or oil
must be removed by a piece of clean dry material
(with no loose fibres) pressed against it, while the
armature is turned by hand. If the commutator is dirty
and has a colour other than its natural colour, lift the
brushes and put a strip of fine carborundum paper or
similar material around the commutator, with the
rough surface to the inside. Turn the armature by
hand until the surface has returned to its natural
colour. Clean the commutator with a material which is
damp with gasolene.
If a repair is necessary to the commutator or switch
gear, etc. the starter must be removed for specialist
repair.
M127 Starter motor
Repair of this starter motor is more difficult. If
necessary, remove the starter motor for specialist
repair.
To test on the engine 23-8
Ensure that the battery is fully charged.
Turn on the lights and operate the starter switch. If no
lights are fitted to the machine, connect a voltmeter
across the battery terminals and operate the starter
switch.
If the starter does not operate but the lights keep their
power or there is no voltage drop across the battery,
check the switch and all the connections and wires.
Slow action of the starter can be caused by faulty
connections.
Failure to engage smoothly between the starter and
the flywheel can be caused, on some types of starter
motor, by dirt on the helical grooves of the starter
motor drive, which can prevent free pinion movement.
Clean the shaft thoroughly with gasolene, or a fluid
made especially for the purpose, and apply a small
quantity of Aero Shell 6B or its equal.
Purchased from www.WorkshopManuals.co.uk