Yale MPB040-E, Manual

Page: 108 / 130

Brush Replacement
1. Motor brushes must be replaced before they are
worn enough to damage the surface of the com-
mutator. Move the brush spring and remove a
brush from its brush holder. Install new brushes
as a set if length of any brush is worn to a mini-
mum length. See Table 3. If the brush lead is fas-
tened to the brush with a rivet, install a new set of
brushes if it is worn to within 3 mm (0.118 in.) of
the rivet. If a brush does not move easily in its
holder, a new set of brushes must be installed. The lead wire for some brushes is installed directly
into the carbon compound of the brush. New
brushes must be installed before the lead wire cuts
a groove in the commutator. Install a new brush set
when a brush is worn to a short length.
Brushes are made to different specifications for
motors used in different applications. Use only new
brushes approved by Yale Company for that motor.
Table 3. Brush Wear Replacement Guide
Brush Height
17 mm
(0.67 in.)
22 mm
(0.87 in.)
28 mm
(1.10 in.)
30 mm
(1.18 in.)
31 mm
(1.22 in.)
32 mm
(1.26 in.)
40 mm
(1.57 in.)
Wear
8 mm
(0.31 in.)
12 mm
(0.47 in.)
14 mm
(0.55 in.)
15 mm
(0.59 in.)
16 mm
(0.63 in.)
16 mm
(0.63 in.)
16 mm
(0.63 in.)
Worn Brush Height
9 mm
(0.35 in.)
10 mm
(0.39 in.)
14 mm
(0.55 in.)
15 mm
(0.59 in.)
15 mm
(0.59 in.)
16 mm
(0.63 in.)
20 mm
(0.79 in.)
NOTE: For some models of lift trucks, the battery
does not need to be removed to access the electric
motors. Other models will require the removal of the
battery before gaining access to the electric motors.
2. Remove battery as necessary for your lift truck.
See
How To Remove Battery in the Operating
Manual or the YRM section Periodic Mainte-
nance for your lift truck.
WARNING
Compressed air can move particles so they cause
injury to the user or to other personnel. Verify the
path of the compressed air is away from all per-
sonnel. Wear protective goggles of a face shield
to prevent injury to the eyes.
3. Remove access plate to motors. Remove brush
covers to motor. See Figure 2. Wear eye protec-
tion. Use a vacuum cleaner or compressed air to
remove dirt and brush dust from commutator
area.
4. Make a note of the arrangement and connections
of the brush assembly. See Figure 4. The new
brushes must be installed in the same positions
from which the worn brushes were removed.
5. Loosen screw that fastens brush wire to its termi-
nal. Remove brush springs and brushes.
6. Inspect brush holders for burns and damage.
Make sure brush holders are fastened tightly to
brush mounting plate at end of motor. Make sure
new brushes will move freely and smoothly in
brush holders. Check that brush mounting plate is
holding brush holder so it does not move.
Brush Replacement 0620 YRM 0294
10