Maintenance And Lubrication - Bosch 3915 Operating/Safety Instructions Manual

Maintenance and Lubrication

Preventive maintenance performed
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by unauthorized personnel may
result in misplacing of internal wires and components
which could cause serious hazard. We recommend
that all tool service be performed by a Bosch Factory
Service Center or Authorized Bosch Service Station.
Carbon Brushes
The brushes and commutator in your tool have been
engineered for many hours of dependable service. To
maintain peak efficiency of the motor, we recommend
every two to six months the brushes be examined.
Only genuine Bosch replacement brushes specially
designed for your tool should be used.
Motor Brush Replacement
To Inspect or Replace Brushes:
1. Unplug the saw.
The brush cap is spring loaded by
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the brush assembly.
2. Remove the brush cap on the motor using a
wide flat blade screwdriver.
3. Pull out the brush (Figure 38). Repeat for the
opposite side.
NOTE: If installing the existing brush or brushes,
make sure the brush goes in the same way it came
out. Otherwise a break-in period will occur that will
reduce motor performance and increase brush wear.
4. Inspect brushes for wear. On the wide flat side of
brush is a wear limit line. If the brush contact
face is at or beyond (no line visible) the limit
replace brushes as a set.
5. Install new brush. The two (2) tabs on the brush
terminal go in the same hole the carbon part fits
into.
6. Tighten the brush cap but do not overtighten.
Figure 38. Motor Brush
Service
Brush
Brush
Terminal
Cleaning
To avoid accidents, always discon-
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nect the tool from the power supply
before cleaning or performing any maintenance. The
tool may be cleaned most effectively with compressed
air. Always wear safety goggles when cleaning tools
with compressed air.
Ventilation openings and switch levers must be kept
clean and free of foreign matter. Do not attempt to
clean by inserting pointed objects through openings.
Check regularly to make sure the lower guard and all
moving parts are working properly.
Remove accumulated sawdust from working parts by
blowing with compressed air or wiping with a damp
cloth.
Certain cleaning agents and sol-
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vents damage plastic parts. Some
of these are: gasoline, carbon tetrachloride, chlorinat-
ed cleaning solvents, ammonia and household deter-
gents that contain ammonia.
Care of Blades
Blades become dull even from cutting regular lumber.
If you find yourself forcing the saw forward to cut
instead of just guiding it through the cut, chances are
the blade is dull or coated with wood pitch.
When cleaning gum and wood pitch from blade,
unplug the saw and remove the blade. Remember,
blades are designed to cut, so handle carefully. Wipe
the blade with kerosene or similar solvent to remove
the gum and pitch. Unless you are experienced in
sharpening blades, we recommend you do not try.
Tool Lubrication
Your Bosch tool has been properly lubricated and is
ready to use. It is recommended that tools with gears
be regreased with a special gear lubricant at every
brush change.
Periodically lubricate moving parts with a silicone, or
light oil spray. Do not use grease because it tends to
attract and hold sawdust.
Bearings
All bearings in this tools are lubricated with a sufficient
amount of high grade lubricant for the life of the unit
under normal operating conditions. No further lubrica-
tion is required.
31.