Central Pneumatic 37730 User manual

3/8”3/8”
3/8”3/8”
3/8” ButterflyButterfly
ButterflyButterfly
Butterfly
Air Impact WrenchAir Impact Wrench
Air Impact WrenchAir Impact Wrench
Air Impact Wrench
ASSEMBLY AND OPERATING INSTRUCTIONS
3491 Mission Oaks Blvd., Camarillo, CA 93011
Visit ourWeb site at http://www.harborfreight.com
Copyright © 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 FreightTools.
For technical questions and replacement parts, please call 1-800-444-3353
37730

SKU37730 Page 2
Specifications
This compact Impact Wrench allows you to get at fasteners in much tighter spots
thanconventional“pistol”designedairimpactwrenches.Itdeliversapowerful50ft/
lbs of torque at 90 PSI, at up to 1580 impacts per minute. It uses standard 1/4” npt
air connections, and a convenient 3/8”drive.The Butterfly switch on top of the tool
allows you to quickly and easily change impact direction. The built in regulator
allows you to instantly change air pressure and torque among 8 settings. Sturdily
built with a polished aluminum body and machined steel components, it is a
versatile tool you will be proud to have in your tool box.
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 fol-
lowed 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 lit. Do not
use electrically powered 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.
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SKU37730 Page 3
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 while working. Do not wear loose clothing or jewelry as
theycanbe caught in movingparts. Protective, electrically non-conductive
clothesandnon-skidfootweararerecommendedwhenworking. Wear
restrictivehair covering to contain longhair.
7. Use eye, face and ear protection. Alwayswear ANSI approved impact
safety goggles.Wear a full face shield if you are producing metal filings or
woodchips.WearanANSIapproveddust mask or respiratorwhenworking
around metal, wood, and chemical dusts and mists. Wear ANSI approved ear
plugs.
8. Do not overreach. Keep proper footing and balance at all times. Do not
reachoveroracrossrunningmachines.
9. Maintain tools with care. Keep tools clean and in good condition for better
andsaferperformance.Followinstructionsforlubricatingandchanging
accessories.Inspect tool fittings and hosesperiodically 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.Disconnect from air pressuresource when not in use.
11. Remove adjusting keys and wrenches. Check that keys and adjusting
wrenchesareremovedfromthe tool or machine work surfacebefore
connecting it.
12. Avoid unintentional starting. Be sure the ButterflyThrottle Switch is in the
neutral, OFF position when not in use and before attaching to pressure
source.Do not carry any tool with your finger on the ButterflyThrottle Switch,
whether it is attached 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 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 the ButterflyThrottle Switch does not function properly.

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15. Guard against electric shock when working on electrical equipment,
such as your air compressor. Prevent body contact with grounded surfaces
suchaspipes, radiators, ranges, and refrigeratorenclosures.
16. Replacement parts and accessories. When servicing,useonlyidentical
replacement parts.Use of any other parts will void the warranty.Only use
accessoriesintended for use with this tool. Approved accessories are
availablefromHarborFreightTools.
17. Do not operate tool if under the influence of alcohol or drugs. Read
warninglabelsonprescriptions to determine if yourjudgmentor reflexes are
impaired while taking drugs. If there is any doubt, do not operate the tool.
18. Use proper size and type air pressure line and fittings. The recommended
air line for this tool is 3/8” delivering no more than 90 psi. Recommended air
inlet size is 1/4” - 18 npt.
19. Maintenance. For your safety, service and maintenance should be performed
regularlybyaqualified technician.
20. You should maintain a proper regulator and moisture trap in your air
line at all times.
Note:Performanceofthistoolmay vary dependingonvariationsinlocalairpressure.
Warning: The warnings, cautions, and instructions discussed in this instruc-
tion manual cannot cover all possible conditions and situations that may oc-
cur. It must be understood by the operator that common sense and caution
are factors which cannot be built into this product, but must be supplied by
the operator.
WARNING: The brass components of this product contain lead, a chemical
known to the State of California to cause birth defects (or other reproductive
harm). (California Health & Safety code 25249.5, et seq. )
Unpacking
When unpacking, Examine the conditiojn of your impact wrench. If any parts are
missing or broken, please call Harbor FreightTools at the number on the cover of
this manual.
Air Impact
Wrench

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Operation
1. Install a standard 1/4” Air Connector (not included) to the Air Inlet (36). First
wrapthethreaded portion of the1/4”air connector with pipethreadseal tape
before threading it into the Air Inlet (36).Tighten securely.
2. Attach a standard quick connector (not included) to your 3/8” air pressure
source hose. Then attach the air hose to the Air Impact Wrench.
NOTE:If you are not using an automatic in-line oiler, add a few drops of pneumatic
oil to the Air Inlet (36) before attaching the air hose. Add a few more drops of oil
aftereveryhourofcontinualuse.
3. Set the air pressure regulator on your air compressor at 90 psi.
WARNING: Donot exceedthe recommended pressure of90 psi.Damage to your
tool,and possiblepersonal injury and/or property damage mayresult.
4. Check the air line and its connections for air leaks. Make note of these, and
repairthembefore using this tool.
NOTE: Turnoffyouraircompressoranddisconnecttheairpressurehosebefore
changing sockets or making any adjustments to this tool. Severe injury or property
damagemayotherwiseresult.
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
bedeliveredtothework piece.
5. Select the appropriate size 3/8” square drive impact socket (not included) for
your needs. Push and snap the socket onto the Anvil (9).
6. Set the direction of the Air Impact
Wrenchto“FORWARD”or
“REVERSE”. Please see photo. By
movingthe ThrottleLever“Butterfly”
(5) to the right, you are setting the
tool to operate FORWARD.You may
control the amount of torque to be
appliedbyrotatingtheRegulator(38)
(Seephotonextpage). Thereare
settings from 1 through 8, indicating
increasingtorque.RocktheThrottle
Lever “Butterfly” (5) to the left to REVERSE the direction of the tool.
NOTE:In this booklet, “FORWARD”refers to clockwise rotation,and “REVERSE”
refersto counterclockwise rotation ofthe Anvil (9). Always be aware of the direction
of the threading of the fastener you are working on. While most fasteners install
withclockwiserotation, some threads areintentionally the reverse.
FORWARD
REVERSE
ThrottleLever“Butterfly”(5)

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NOTE:Theactual torque deliveredateach of the eight
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(notsupplied).
7. If installing a nut or bolt, set it as tight as possible by
handbeforetighteningwiththeAirImpactWrench.
8. Place the socket (not included) over the fastener.
9. Grip the Air ImpactWrench tightly with both hands,
and rock theThrottle Lever“Butterfly”(5) to the
right.The toolwill operate and tightenthefastener.
10. When the fastener is tightened, release theThrottle Lever “Butterfly”(5) , and
remove the tool from the fastener.
11. If possible, check the actual torque applied to the fastener with a mechanical
torquewrench(notsupplied).
12. If removing a fastener, grip the Air Impact Wrench tightly with both hands, and
rock theThrottle Lever“Butterfly”(5) to the left.The tool will operate and
loosen the fastener (assuming that the fastener is a standard right-hand
thread).NOTE: Always check to be sure of the thread direction of any
fastener before attempting to install or remove it. If the fastener is a left-hand
thread, rock theThrottle Lever “Butterfly”(5) to the right for removal.
WARNING:If the fastener will not come off,first check to be sure of the
direction of the thread. If you have the thread direction correct and the fas-
tener will not come off,DO NOT INCREASETHE AIR PRESSURE to the tool
beyond 90 psi.This may damage the tool.You may have to use penetrating
oil,heat,or a mechanical wrench to remove the fastener.
13. When you are done using this tool, turn off the air compressor, and disconnect
the air hose.Put the Air Impact Wrench away in its proper storage place.
Regulator(38)
Maintenance
1. Your Air Impact Wrench should be kept clean and dry.
2. When not in use, store your tool in a suitable place where it will not be
exposedtowater,corrosivematerials,orunduebangingaround.
3. If you are not using an in-line oiler, you should inject a few drops of pneumatic
oil into the air inlet of the tool and the Oiler Screw (3) port after every hour of
continuoususe.
4. If your tool loses power, or you notice air leaks, take it to a certified technician for service.
5. All repairs to this tool should be performed by a qualified service technician.

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Parts List
NOTE: Some parts are listed and shown for illustration purposes only and are not
available individually as replacement parts.
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PLEASE READ THE FOLLOWING CAREFULLY
THE MANUFACTURER AND/OR DISTRIBUTOR HAS PROVIDED THE PARTS DIAGRAM
IN THIS MANUAL AS A REFERENCETOOL ONLY. NEITHER THE MANUFACTURER NOR
DISTRIBUTOR MAKES ANY REPRESENTATION OR WARRANTY OF ANY KIND TO THE
BUYER THAT HE OR SHE IS QUALIFIEDTO MAKE ANY REPAIRS TOTHE PRODUCT OR
THAT HE OR SHE IS QUALIFIED TO REPLACE ANY PARTS OFTHE PRODUCT. IN FACT,
THE MANUFACTURER AND/OR DISTRIBUTOR EXPRESSLY STATES THAT ALL REPAIRS
AND PARTS REPLACEMENTS SHOULD BE UNDERTAKEN BY CERTIFIED AND
LICENSED TECHNICIANS AND NOT BY THE BUYER.THE BUYER ASSUMES ALL RISK
AND LIABILITY ARISING OUT OF HIS OR HER REPAIRS TO THE ORIGINAL PRODUCT
OR REPLACEMENT PARTSTHERETO, OR ARISING OUT OF HIS OR HER INSTALLATION
OF REPLACEMENT PARTS THERETO.

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Assembly Drawing