Maintenance; Replacing Carbon Brushes - Makita GA5020 Instruction Manual

Operation with abrasive cut-off /
diamond wheel (optional accessory)
► Fig.19: 1. Lock nut 2. Abrasive cut-off wheel/dia-
mond wheel 3. Inner flange 4. Wheel guard
for abrasive cut-off wheel/diamond wheel
The direction for mounting the lock nut and the inner flange
varies by wheel thickness. Refer to the table below.
115 mm (4-1/2") / 125 mm (5") / 150 mm (6")
Abrasive cut-off wheel
Thickness: Less than
4 mm (5/32")
1
2
22.23 mm (7/8")
3
1. Lock nut 2. Abrasive cut-off wheel
WARNING:
• When using an abrasive cut-off / diamond
wheel, be sure to use only the special wheel
guard designed for use with cut-off wheels.
• NEVER use cut-off wheel for side grinding.
• Do not "jam" the wheel or apply excessive
pressure. Do not attempt to make an excessive
depth of cut. Overstressing the wheel increases
the loading and susceptibility to twisting or
binding of the wheel in the cut and the possibility
of kickback, wheel breakage and overheating of
the motor may occur.
• Do not start the cutting operation in the work-
piece. Let the wheel reach full speed and care-
fully enter into the cut moving the tool forward
over the workpiece surface. The wheel may
bind, walk up or kickback if the power tool is
started in the workpiece.
• During cutting operations, never change the
angle of the wheel. Placing side pressure on
the cut-off wheel (as in grinding) will cause the
wheel to crack and break, causing serious per-
sonal injury.
• A diamond wheel shall be operated perpendicu-
lar to the material being cut.
Thickness: 4 mm (5/32")
or more
22.23 mm (7/8")
Diamond wheel
Thickness: Less than
4 mm (5/32")
1
4
22.23 mm (7/8")
3. Inner flange 4. Diamond wheel

MAINTENANCE

CAUTION:
• Always be sure that the tool is switched off and unplugged
before attempting to perform inspection or maintenance.
• Never use gasoline, benzine, thinner, alcohol or the
like. Discoloration, deformation or cracks may result.
The tool and its air vents have to be kept clean.
Regularly clean the tool's air vents or whenever the
vents start to become obstructed.
► Fig.20: 1. Exhaust vent 2. Inhalation vent

Replacing carbon brushes

► Fig.21: 1. Limit mark
Remove and check the carbon brushes regularly. Replace when
they wear down to the limit mark. Keep the carbon brushes clean
and free to slip in the holders. Both carbon brushes should be
replaced at the same time. Use only identical carbon brushes.
Use a screwdriver to remove the brush holder caps.
Take out the worn carbon brushes, insert the new ones
and secure the brush holder caps.
► Fig.22: 1. Brush holder cap 2. Screwdriver
After replacing brushes, plug in the tool and break in
brushes by running tool with no load for about 10 min-
utes. Then check the tool while running and electric
brake operation when releasing the switch trigger. If
electric brake is not working well, ask your local Makita
service center for repair. (For models GA5020/GA6020)
To maintain product SAFETY and RELIABILITY, repairs,
any other maintenance or adjustment should be per-
formed by Makita Authorized Service Centers, always
using Makita replacement parts.
11 ENGLISH
Thickness: 4 mm (5/32")
or more
22.23 mm (7/8")
3