Maintenance; Charger Cleaning Instructions - DeWalt DCD990 Instruction Manual

2. Use sharp drill bits only. For MASONRY, such as brick, cement,
cinder block, etc., use carbide-tipped bits rated for percussion
drilling.
3. Always apply pressure in a straight line with the bit. Use enough
pressure to keep drill biting, but do not push hard enough to stall
the motor or defl ect the bit.
4. Hold tool fi rmly with both hands to control the twisting action of the
drill. If model is not equipped with side handle, grip drill with one
hand on the handle and one hand on the battery pack.
WARNING: Drill may stall if overloaded causing a sudden twist.
Always expect the stall. Grip the drill fi rmly to control the twisting
action and avoid injury.
5. IF DRILL STALLS, it is usually because it is being overloaded
or improperly used. RELEASE TRIGGER IMMEDIATELY,
remove drill bit from work, and determine cause of stalling. DO
NOT DEPRESS TRIGGER ON AND OFF IN AN ATTEMPT
TO START A STALLED DRILL — THIS CAN DAMAGE THE
DRILL.
6. To minimize stalling or breaking through the material, reduce
pressure on drill and ease the bit through the last fractional part of
the hole.
7 . Keep the motor running when pulling the bit back out of a drilled
hole. This will help prevent jamming.
Hammerdrilling (Fig. 5)
1. Select the desired speed/torque range using the gear shifter to
match the speed and torque to the planned operation. Turn the
collar (E) to the hammerdrill symbol.
IMPORTANT: Use carbide-tipped or masonry bits rated for
percussion drilling only.
2. Drill with just enough force on the hammer to keep it from bouncing
excessively or "rising" off the bit. Too much force will cause slower
drilling speeds, overheating, and a lower drilling rate.
3. Drill straight, keeping the bit at a right angle to the work. Do not
exert side pressure on the bit when drillling as this will cause
clogging of the bit fl utes and a slower drilling speed.
4. When drilling deep holes, if the hammer speed starts to drop off,
pull the bit partially out of the hole with tool still running to help clear
debris from the hole.
NOTE: A smooth, even fl ow of dust from the hole indicates proper
drilling rate.

MAINTENANCE

WARNING: To reduce the risk of serious personal injury, place
the forward/reverse button in the lock-off position or turn tool
off and disconnect battery pack before making any adjustments
or removing/installing attachments or accessories. An accidental
start-up can cause injury.
Cleaning
WARNING: Blow dirt and dust out of all air vents with clean, dry air
at least once a week. To minimize the risk of eye injury, always wear
ANSI Z87.1 approved eye protection when performing this.
WARNING: Never use solvents or other harsh chemicals for
cleaning the non-metallic parts of the tool. These chemicals may
weaken the plastic materials used in these parts. Use a cloth
dampened only with water and mild soap. Never let any liquid get
inside the tool; never immerse any part of the tool into a liquid.

CHARGER CLEANING INSTRUCTIONS

WARNING: Shock hazard. Disconnect the charger from the AC
outlet before cleaning. Dirt and grease may be removed from the
exterior of the charger using a cloth or soft non-metallic brush. Do not
use water or any cleaning solutions.
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