RIDGID R4121 Operator's Manual page 35

MAINTENANCE
BRUSH REPLACEMENT
See Figure 43.
The saw has externally accessible brush assemblies that
should be periodically checked for wear.
Proceed as follows when replacement is required:
 Unplug the saw.
WARNING:
Failure to unplug the saw could result in accidental
starting causing serious injury.
 Remove brush cap with a screwdriver. Brush assembly is
spring loaded and will pop out when you remove brush
cap.
 Remove brush assembly.
 Check for wear. Replace both brushes when either has
less than 1/4 in. length of carbon remaining. Do not
replace one side without replacing the other.
 Reassemble using new brush assemblies. Make sure
curvature of brush matches curvature of motor and that
brush moves freely in brush tube.
 Make sure brush cap is oriented correctly (straight) and
replace.
 Tighten brush cap securely. Do not overtighten.
CHANGING THE BATTERIES
See Figure 44.
 Unplug the saw.
 Rotate and hold lower blade guard up.
 Using the hex key (1/16 in.) provided, loosen the screw
then separate the cover from the laser guide.
 Lower the blade guard.
 Remove the three button cell batteries.
NOTE: Replace the batteries with button cell batteries
that have a rating of 1.5 volt and 100 mAh (milliampere
hour) minimum (number 76 series or equivalent).
When replacing the batteries, the laser guide should be
thoroughly cleaned. Use a soft paintbrush, or similar
device, to remove all sawdust and debris.
 After cleaning the laser guide and replacing batteries,
secure battery cover to laser guide using the screw.
Tighten screw securely.
WARNING:
Use of controls or adjustments or performance of
procedures other than those specified herein may
result in hazardous radiation exposure.
BRUSH
ASSEMBLY
BRUSH
CAP
BATTERIES
BATTERY
COVER
LASER
GUIDE
35
BRUSH
ASSEMBLY
SCREW
NEGATIVE (–)
BRUSH
CAP
Fig. 43
BATTERY
COVER
Fig. 44