Central Pneumatic 94109 User manual

1” TWIN HAMMER
AIR IMPACT WRENCH
Model 94109
ASSEMBLY AND OPERATING INSTRUCTIONS
Visit our website at: http://www.harborfreight.com
Read this material before using this product.
Failure to do so can result in serious injury.
SAVE THIS MANUAL.
Copyright©2006 by Harbor Freight Tools®. All rights reserved. No portion of this manual or any artwork con-
tained herein may be reproduced in any shape or form without the express written consent of Harbor Freight
Tools. Diagrams within this manual may not be drawn proportionally. Due to continuing improvements, actual
product may differ slightly from the product described herein. Tools required for assembly and service may not
be included.
For technical questions or replacement parts, please call 1-800-444-3353.
Revised Manual 11h

Page 2SKU 94109 For technical questions, please call 1-800-444-3353
Specications
Item Description
Torque 1,500 FT./LBS.
Working Pressure 100 PSI, 115 PSI = maximum air pressure
Air Consumption 14 CFM Average
Air Inlet 1/2 inch - 14 NPT with screen
Drive One inch, Inline air impact; 9” extended anvil
Regulator on Unit 3 torque settings: 1, 2, & 3; Left and Right Direction
Overall Dimensions 22” (L) x 8-1/4” (W) x 6-1/2” (H) with side handle
Weight 25.8 LBS.
Save This Manual
You will need the manual for the safety warnings and precautions, assembly instructions,
operating and maintenance procedures, parts list and diagram. Keep your invoice with this
manual. Write the invoice number on the inside of the front cover. Keep the manual and
invoice in a safe and dry place for future reference.
Safety Warnings and Precautions
WARNING: When using tool, basic safety precautions should always be followed to
reduce the risk of personal injury and damage to equipment.
Read all instructions before using this tool!
1. Keep work area clean. Cluttered areas invite injuries.
2. Observe work area conditions. Do not use machines or power tools in damp or wet
locations. Don’t expose to rain. Keep work area well lighted. Do not use electrically
powered tools in the presence of ammable gases or liquids.
3. Keep children away. Children must never be allowed in the work area. Do not let
them handle machines, tools, or extension cords.
4. Store idle equipment. When not in use, tools must be stored in a dry location to
inhibit rust. Always lock up tools and keep out of reach of children.
5. Use the right tool for the job. Do not attempt to force a small tool or attachment to
do the work of a larger industrial tool. There are certain applications for which this
tool was designed. It will do the job better and more safely at the rate for which it was
intended. Do not modify this tool and do not use this tool for a purpose for which it
was not intended.
6. Dress properly. Do not wear loose clothing or jewelry as they can be caught in
moving parts. Protective, electrically non-conductive clothes and non-skid footwear
are recommended when working. Wear restrictive hair covering to contain long hair.
7. Do not overreach. Keep proper footing and balance at all times. Do not reach over
or across running machines.
8. Use eye and ear protection. Always wear ANSI approved impact safety goggles.

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Wear a full face shield if you are producing metal lings or wood chips. Wear an ANSI
approved dust mask or respirator when working around metal, wood, and chemical
dusts and mists.
9. Maintain tools with care. Keep tools sharp and clean for better and safer
performance. Follow instructions for lubricating and changing accessories. Inspect
tool cords periodically and, if damaged, have them repaired by an authorized
technician. The handles must be kept clean, dry, and free from oil and grease at all
times.
10. Disconnect power. Unplug tool when not in use.
11. Remove adjusting keys and wrenches. Check that keys and adjusting wrenches
are removed from the tool or machine work surface before plugging it in.
12. Avoid unintentional starting. Be sure the switch is in the Off position when not
in use and before plugging in. Do not carry any tool with your nger on the trigger,
whether it is plugged in or not.
13. Stay alert. Watch what you are doing, use common sense. Do not operate any tool
when you are tired.
14. Check for damaged parts. Before using any tool, any part that appears damaged
should be carefully checked to determine that it will operate properly and perform its
intended function. Check for alignment and binding of moving parts; any broken parts
or mounting xtures; and any other condition that may affect proper operation. Any
part that is damaged should be properly repaired or replaced by a qualied technician.
Do not use the tool if any switch does not turn On and Off properly.
15. Replacement parts and accessories. When servicing, use only identical
replacement parts. Use of any other parts will void the warranty. Only use accessories
intended for use with this tool. Approved accessories are available from Harbor
Freight Tools.
16. Do not operate tool if under the inuence of alcohol or drugs. Read warning
labels if taking prescription medicine to determine if your judgment or reexes are
impaired while taking drugs. If there is any doubt, do not operate the tool.
17. Maintenance. For your safety, service and maintenance should be performed
regularly by a qualied technician.
18. Use both hands when operating. This tool requires the use of both hands when
operating. This helps maintain tool stability and keeps hands away from the working
area of the tool.
Note: Performance of this tool may vary depending on variations in air compressor performance.

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19. Only use Impact Sockets with this tool. Standard sockets will not withstand
the force applied by this tool, and may break, possible causing personal injury
and/or property injury.
20. Use only specied operating air pressure. Never operate tool above the
recommended working pressure of 100 PSI.
21. Do not use combustible gases. Do not use combustible gases as a power source,
or use tool in areas where combustible gases are stored.
22. OSHA Guidelines. Industrial applications must follow OSHA guidelines.
23. Air Compressor. Read and adhere to all warnings and instructions in the Air
Compressor Instruction Manual.
Warning: The warnings, cautions, and instructions discussed in this instruction manual
cannot cover all possible conditions and situations that may occur. It must be under-
stood by the operator that common sense and caution are factors which cannot be
built into this product, but must be supplied by the operator.
Unpacking
When unpacking, check to make sure the components shown below are included. If any
parts are missing or broken, please call Harbor Freight Tools at the number on the cover of
this manual as soon as possible.
Side Handle (8)
Cap Screws (7)
Allen Wrench
Impact Wrench

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Assembly
The only assembly required is to install Side Handle (8), per the following instruc-
tions. Using Cap Screws (7), and the supplied Allen Wrench, mount the Side Handle (8)
to the Front Casing (5). Securely tighten all Cap Screws (7).
Note: Use pipe thread seal or Teon tape on all threaded connections.
Oiler and Filter Connection
Dirt, water, and the lack of pneumatic tool oil are major causes for tool wear. It is recom-
mended to install an optional oiler-lter, as illustrated below for better performance.
Connect the air tool, air hoses, lter, and oiler to the Compressor Air Outlet as illustrated
below. The lter and oiler (not supplied) are recommended but not mandatory for opera-
tion.
A few drops of pneumatic tool oil must be added through the air inlet before each use if an
oiler is not used.
OPERATION
1. Install a standard 1/2” Air Connector (not included) to the Air Inlet (51). First wrap
the threaded portion of the 1/2” air connector with pipe thread seal tape before
threading it into the Air Inlet (51). Tighten securely.
2. Set the sir pressure regulator at no more than 100 PSI.
3. Check the air line and its connections for air leaks, make note of these, and repair
them before using this tool.
WARNING: Do not exceed the recommended working pressure of 100 PSI. Damage to
your tool, and possible personal injury may result.

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OPERATION (continued)
NOTE: Turn off your air compressor and disconnect the air pressure hose before changing
sockets or making any adjustments to this tool. Severe injury or property damage may result
otherwise.
WARNING: This tool generates considerable torque when in use. Always hold the tool with
both hands when using, and brace yourself to resist the torque which will be delivered to the
work piece.
1. Select the appropriate size 1” square drive socket (not included) for your needs. Push
and snap the socket onto the Anvil (13).
NOTE: On this tool the designation “R” refers to forward or clockwise rotation. “L”
refers to reverse or counterclockwise rotation. Always be aware of the direction
of the threading of the fasteners you are working on. While most fasteners install
with clockwise rotation, some threads are intentionally the reverse.
2. Set the directions of the Air Impact Wrench to Forward (R=right or clockwise) or
Reverse (L=left or counterclockwise) by adjusting the Rotation/Torque Knob (38).
You may control the amount of torque to be applied by selecting any of the 3 torque
settings (1=low, 2=medium, 3=high).
NOTE: The actual torque delivered at each of the 3 torque settings will depend on the air
pressure supplied to the tool. We suggest that you test the actual torque by tightening a nut
or bolt at each setting, then observing the resultant torque by using a mechanical torque
wrench (not supplied).
3. If installing a nut or bolt, set it as tight as possible by hand.
4. Place and push on a appropriate size impact socket onto Anvil (13) and place the Impact
Socket (not included) over the fastener.
5. Grip the Air Impact Wrench tightly with both hands, and squeeze the Trigger (36). The
tool will operate and tighten the fastener.
Rotation / Torque Knob (38) Air Inlet Connector (51)

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Caution: Never increase pressure at the air compressor regulator to achieve more torque.
7. When nished, release the Trigger (36), and lift the Impact Wrench off the nut.
8. Remove the air supply hose, then squeeze the Trigger (36) again to release any
remaining air pressure in the Impact Wrench air chamber.
Maintenance
1. After each use, wipe the Impact Wrench with a clean cloth to remove any dirt and
grease buildup.
2. To maintain tool life, always lubricate the air line by adding a few drops of pneumatic
tool oil to the air line (or Air Inlet) before each use. Or, install the automatic oiler-lter
system as illustrated on page 5.
3. Before each use, drain water out of the air compressor tank and condensation from
the air lines. Refer to the Air Compressor Operation Manual.
4. Store the Impact Wrench in a clean and dry location.
OPERATION (continued)

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Parts List

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Assembly Drawing
NOTE: Some parts are listed and shown for illustration purposes only and are not available
individually as replacement parts.

Page 10SKU 94109 For technical questions, please call 1-800-444-3353
Lubrication
Gear oil should be added in part #4, use MoS2 lubricating grease. It should be added
monthly. The amount is 0.033-0.044lbs each time. Gear oil should be added in part #44,
use Spindle Oil. Add 5-10 drops every day, before operating the tool.
Rev 10d
90 Day Warranty
Harbor Freight Tools Co. makes every effort to
assure that its products meet high quality and
durability standards, and warrants to the original
purchaser that this product is free from defects in
materials and workmanship for the period of 90
days from the date of purchase. This warranty does
not apply to damage due directly or indirectly, to
misuse, abuse, negligence or accidents, repairs or
alterations outside our facilities, criminal activity,
improper installation, normal wear and tear, or
to lack of maintenance. We shall in no event be
liable for death, injuries to persons or property, or
for incidental, contingent, special or consequential
damages arising from the use of our product.
Some states do not allow the exclusion or limitation
of incidental or consequential damages, so the
above limitation of exclusion may not apply to
you. THIS WARRANTY IS EXPRESSLY IN LIEU
OF ALL OTHER WARRANTIES, EXPRESS OR
IMPLIED, INCLUDING THE WARRANTIES OF
MERCHANTABILITY AND FITNESS.
To take advantage of this warranty, the product
or part must be returned to us with transportation
charges prepaid. Proof of purchase date and an
explanation of the complaint must accompany the
merchandise. If our inspection veries the defect,
we will either repair or replace the product at our
election or we may elect to refund the purchase
price if we cannot readily and quickly provide
you with a replacement. We will return repaired
products at our expense, but if we determine there
is no defect, or that the defect resulted from causes
not within the scope of our warranty, then you must
bear the cost of returning the product.
This warranty gives you specic legal rights and
you may also have other rights which vary from
state to state.