Central Pneumatic 53176 User manual

1/2” Air Impact Wrench
Model 53176
Assembly and Operating Instructions
3491 Mission Oaks Blvd., Camarillo, CA 93011
Copyright©1998, 2004 by Harbor Freight Tools®. All rights reserved.
No portion of this manual or any artwork contained herein may be
reproduced in any shape or form without the express written consent
of Harbor Freight Tools.
For technical questions and replacement parts, please call 1-800-444-3353
®
®
REV 07/04

SKU 53176 For technical questions, please call 1-800-444-3353. Page 2
Specifications
Maximum Torque: 250 ft. lbs.
Bolt Capacity: 5/8”
1/2” Square Drive
Reversible Drive
Includes 4 Piece Standard
Socket Set: 1/2”, 3/8”, 9/16”, 5/8”
PSI: 90
RPM: 7,000
1/4” NPT Air Inlet
3/8” Hose Size
Standard Anvil
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 in-
voice 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 pow-
ered tools in the presence of flammable 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. Do not force tool. It will do the job better and more safely at the rate for which it was
intended. Do not use inappropriate attachments in an attempt to exceed the tool capacity.
6. 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. Do not use a tool for a purpose for which it was not intended.
7. Dress properly. Do not wear loose clothing or jewelry as they can be caught in moving

SKU 53176 For technical questions, please call 1-800-444-3353. Page 3
parts. Protective, electrically non-conductive clothes and non-skid footwear are recom-
mended when working. Wear restrictive hair covering to contain long hair.
8. Use eye and ear protection. Always wear ANSI approved impact safety goggles. Wear a
full face shield if you are producing metal filings or wood chips.Wear an ANSI approved dust
mask or respirator when working around metal, wood, and chemical dusts and mists.
9. Do not overreach. Keep proper footing and balance at all times. Do not reach over or
across running machines.
10. 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.
11. Disconnect power. Unplug when not in use. Do not yank power cord from the receptacle.
Do not carry tools by the cord.
12. Remove adjusting keys and wrenches. Check that keys and adjusting wrenches are
removed from the tool or machine work surface before plugging it in.
13. 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 finger on the trigger, whether it is plugged
in or not.
14. Stay alert. Watch what you are doing, use common sense. Do not operate any tool when
you are tired.
15. 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
fixtures; and any other condition that may affect proper operation. Any part that is damaged
should be properly repaired or replaced by a qualified technician. Do not use the tool if any
switch does not turn On and Off properly.
16. Guard against electric shock. Prevent body contact with grounded surfaces such as pipes,
radiators, ranges, and refrigerator enclosures.
17. 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.
18. Do not operate tool if under the influence of alcohol or drugs. Read warning labels on
prescriptions to determine if your judgment or reflexes are impaired while taking drugs. If
there is any doubt, do not operate the tool.
Unpacking
When unpacking, check the parts diagram and part number listing on page 6 to make sure
all parts are included. If any parts are missing or damaged, please call Harbor Freight Tools at
the telephone number on the cover of this manual as soon as possible.
Your Air Impact Wrench comes pre-assembled. To complete preparations for use, follow the
steps shown on the following page. Part numbers shown below identify parts shown on the part
number listing on page 6.

SKU 53176 For technical questions, please call 1-800-444-3353. Page 4
Air Connection
1. Remove the Screen from the Inlet (both included in part 42). You will need an air hose
fitting (sold separately) before you can connect your Impact Wrench to an air compressor.
2. Attach the air hose fitting to the Inlet and tighten with a wrench.
3. Attach a quick-disconnect coupler (sold separately) to the air hose fitting if desired. This
is a useful accessory as it allows quick-coupling action when using a variety of tools with the
same air compressor.
4. The Impact Wrench is ready for use.
Operation
Frequent but not excessive, lubrication is required for best performance. Oil added through
the airline connection will lubricate internal parts. An automatic airline oiler is recommended but
oil may be added manually before every operation or after about 1 hour of continuous use. Only
a few drops of oil at a time are necessary. Too much oil will collect inside the tool and be blown out
during the exhaust cycle. ONLY USE PNEUMATIC TOOL OIL. Do not use detergent oil or
additives as these lubricants will cause accelerated wear to the seals in the tool.
Dirt and water in the air supply are major causes of pneumatic tool wear. Use a filter/oiler for
better performance and longer life. The filter must have adequate flow capacity for the specific
application. Consult the manufacturer’s instructions for proper maintenance of your filter.
The connector on the tool must not hold pressure when the air supply is disconnected. If the
wrong fitting is used, the tool can remain charged with air after being disconnected.
Your Impact Wrench features an air Regulator (37), allowing you to vary the amount of torque
exerted on the nut or bolt you are working on. Setting “1” is the lowest setting, and is recom-
mended for smaller nuts and bolts. Setting “4” is the highest setting and provides the most torque
and speed.
Loosening
1. Attach the correct size socket to the Anvil (8).
2. Set the compressor’s pressure regulator to 90 PSI. Do not set the compressor’s outlet
regulator above 90 PSI.
3. Connect the Impact Wrench to the air compressor’s hose. If leaking is detected, discon-
nect the air hose and repair before use.
4. Place the socket over the nut to loosen.
5. Grip the Impact Wrench firmly. Press the Reverse Valve (44) in from the area above the
Trigger (29) so that the Reverse Valve protrudes out the back of the Housing. Press the Trigger to
start the Impact Wrench.
Caution: Make sure the nut or bolt can withstand the Impact Wrench’s working torque.

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6. If the Impact Wrench cannot loosen the nut, DO NOT raise the outlet pressure of the air
compressor.
7. If the Impact Wrench’s Air Regulator is set on a low setting, you may raise the setting and
try again. If the Impact Wrench’s Air Regulator is already set on the “4” setting, do not continue
attempts to loosen the nut with the Impact Wrench. Use other appropriate tools and methods to
loosen the nut.
8. When the nut is removed, stop the Impact Wrench by releasing the Trigger and remove the
Impact Wrench from the nut. Remove the nut from the socket if needed.
Tightening
The working torque of the Impact Wrench is 250 feet/lbs. Make sure the nut or bolt you are
using the Impact Wrench to tighten can withstand the rated torque.
1. Tighten the nut on as far as you can by hand.
2. Place the socket on the nut. Press the Reverse Valve forward so it protrudes out the front
of the Housing. Press the Trigger to start the Impact Wrench.
3. If the Impact Wrench stalls while tightening, DO NOT raise the outlet pressure of the air
compressor above 90 PSI.
4. If the Impact Wrench’s Air Regulator is set on a low setting, it may be raised before you try
again. If the nut will not tighten at the maximum setting, do not continue attampts to tighten the
nut. Use other appropriate tools and methods to tighten the nut.
5. When the nut has been tightened, remove the Impact Wrench and socket. Do not over-
tighten.
6. If available, check the recommended torque specifications for the nut. You should use a
torque wrench to torque the nut after using the Impact Wrench.
Maintenance
The Impact Wrench is best operated with an airline oiler. If you are using the Impact Wrench
without an airline oiler, perform the following maintenance:
Disconnect the Impact Wrench from the air hose. Apply a few drops of pneumatic
tool oil through the air line before each use, or every hour if used continuously.
Apply a few drops of oil to the Trigger mechanism. Work the Trigger a few times to
lubricate.
Note: Do not use detergent oil or additives as these lubri-
cants will cause accelerated wear to the tool’s seals.

SKU 53176 For technical questions, please call 1-800-444-3353. Page 6
Parts Listing and Parts Diagram