Central Pneumatic 21 User manual

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21
GAL cast iron
vertical air
compressor
Owner’s Manual & Safety Instructions
Save This Manual Keep this manual for the safety warnings and precautions, assembly,
operating, inspection, maintenance and cleaning procedures. Write the product’s serial number in the
back of the manual near the assembly diagram (or month and year of purchase if product has no number).
Keep this manual and the receipt in a safe and dry place for future reference.
When unpacking, make sure that the product is intact
and undamaged. If any parts are missing or broken,
please call 1-888-866-5797 as soon as possible.
Copyright©2013 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.
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.
Read this material before using this product.
Failure to do so can result in serious injury.
SAVE THIS MANUAL.
REV 15a

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SAFETY SETUP OPERATION MAINTENANCE
Table of Contents
Safety ......................................................... 2
Setup .......................................................... 6
Specifications ............................................. 6
Operation................................................... 11
Maintenance.............................................. 14
Parts List and Diagram.............................. 18
Warranty .................................................... 20
WARNING SYMBOLS AND DEFINITIONS
This is the safety alert symbol. It is used to alert you to potential
personal injury hazards. Obey all safety messages that
follow this symbol to avoid possible injury or death.
Indicates a hazardous situation which, if not avoided,
will result in death or serious injury.
Indicates a hazardous situation which, if not avoided,
could result in death or serious injury.
Indicates a hazardous situation which, if not avoided,
could result in minor or moderate injury.
Addresses practices not related to personal injury.

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SAFETYSETUPOPERATIONMAINTENANCE
IMPORTANT SAFETY INFORMATION
General Safety Warnings
WARNING Read all safety warnings and instructions.
Failure to follow the warnings and instructions may result in electric shock, fire and/or serious injury.
Save all warnings and instructions for future reference.
The warnings, precautions, and instructions discussed in this instruction manual cannot cover all possible
conditions and situations that may occur. 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.
1. Work area safety
a. Keep work area clean and well lit.
Cluttered or dark areas invite accidents.
b. Do not operate the Compressor in explosive
atmospheres, such as in the presence
of flammable liquids, gases or dust.
Compressor motors produce sparks
which may ignite the dust or fumes.
c. Keep children and bystanders away
from an operating compressor.
2. Electrical safety
a. Compressor plugs must match the outlet.
Never modify the plug in any way.
Do not use any adapter plugs with grounded
compressors. Standard plugs and matching
outlets will reduce risk of electric shock.
b. Do not expose compressor to rain or wet
conditions. Water entering a compressor
will increase the risk of electric shock.
c. Do not abuse the cord. Never use the
cord for unplugging the compressor.
Keep cord away from heat, oil, sharp edges
or moving parts. Damaged or entangled
cords increase the risk of electric shock.
3. Personal safety
a. Stay alert, watch what you are doing and
use common sense when operating this
compressor. Do not use this compressor
while you are tired or under the influence
of drugs, alcohol or medication. A moment
of inattention while operating a compressor
may result in serious personal injury.
b. Use personal protective equipment.
Always wear ANSI-approved eye
protection during setup and use.
c. Prevent unintentional starting. Ensure the
switch is in the off-position before connecting
to power source or moving the compressor.
4. Compressor use and care
a. Do not use the compressor if the switch
does not turn it on and off. Any compressor
that cannot be controlled with the switch
is dangerous and must be repaired.
b. Disconnect the plug from the power source
before making any adjustments, changing
accessories, or storing the compressor.
Such preventive safety measures reduce the
risk of starting the compressor accidentally.
c. Store an idle compressor out of the reach
of children and do not allow persons
unfamiliar with the compressor or these
instructions to operate it. A compressor is
dangerous in the hands of untrained users.
d. Maintain the compressor. Keep the
compressor clean for better and safer
performance. Follow instructions for
lubricating and changing accessories.
Keep dry, clean and free from oil and grease.
Check for misalignment or binding of moving
parts, breakage of parts and any other
condition that may affect the compressor’s
operation. If damaged, have the compressor
repaired before use. Many accidents are
caused by a poorly maintained compressor.
e. Use the compressor in accordance with
these instructions, taking into account
the working conditions and the work to
be performed. Use of the compressor for
operations different from those intended
could result in a hazardous situation.
5. Service
a. Have your compressor serviced by a
qualified repair person using only identical
replacement parts. This will ensure that the
safety of the compressor is maintained.

Page 4 For technical questions, please call 1-888-866-5797. ITEM 61454
SAFETY SETUP OPERATION MAINTENANCE
Air Compressor Safety Warnings
1. Risk of fire or explosion - do not spray
flammable liquid in a confined area or towards a
hot surface. Spray area must be well-ventilated.
Do not smoke while spraying or spray where
spark or flame is present. Arcing parts - keep
compressor at least 20 feet away from explosive
vapors, such as when spraying with a spray gun.
2. Risk of bursting - do not adjust regulator higher
than marked maximum pressure of attachment.
3. Risk of injury - do not direct air
stream at people or animals.
4. Do not use to supply breathing air.
5. Do not leave compressor unattended
for an extended period while plugged in.
Unplug compressor after working.
6. Keep compressor well-ventilated.
Do not cover compressor during use.
7. Drain Tank daily and after use. Internal rust causes
tank failure and explosion.
8. Add correct amount of compressor oil before first
use and every use. Operating with low or no oil
causes permanent damage and voids warranty.
9. Do not remove the valve cover or
adjust internal components.
10. Compressor head gets hot during operation.
Do not touch it or allow children nearby
during or immediately following operation.
11. Do not use the air hose to move the compressor.
12. Release the pressure in the
storage tank before moving.
13. The use of accessories or attachments not
recommended by the manufacturer may
result in a risk of injury to persons.
14. All air line components, including hoses, pipe,
connectors, filters, etc., must be rated for a minimum
working pressure of 150 PSI, or 150% of the
maximum system pressure, whichever is greater.
15. USE OF AN EXTENSION CORD IS NOT
RECOMMENDED. If you choose to use an
extension cord, use the following guidelines:
TABLE A: RECOMMENDED MINIMUM WIRE
GAUGE FOR EXTENSION CORDS
(120 VOLT)
NAMEPLATE
AMPERES
(at full load)
EXTENSION CORD
LENGTH
25′ 50′ 100′ 150′
0 – 6 18 16 16 14
6.1 – 10 18 16 Do not use.
10.1 – 12 16 16 Do not use.
12.1 – 16 14 12 Do not use.
a. Make sure your extension cord
is in good condition.
b. Be sure to use an extension cord which
is heavy enough to carry the current your
product will draw. An undersized cord will
cause a drop in line voltage resulting in loss
of power and overheating. Table A shows the
correct size to use depending on cord length
and nameplate ampere rating. If in doubt,
use the next heavier gauge. The smaller
the gauge number, the heavier the cord.
16. Industrial applications must follow OSHA guidelines.
17. Maintain labels and nameplates on the
compressor. These carry important safety
information. If unreadable or missing, contact
Harbor Freight Tools for a replacement.
18. This product is not a toy.
Keep it out of reach of children.
19. Operate unit on level surface. Check oil level
daily and fill to marked level if needed.
20. People with pacemakers should consult their
physician(s) before use. Electromagnetic fields in
close proximity to heart pacemaker could cause
pacemaker interference or pacemaker failure.
21. WARNING: The brass components of this product
contain lead, a chemical known to the State
of California to cause cancer and birth defects
or other reproductive harm. (California Health
& Safety Code § 25249.5, et seq.)
22. WARNING: The cord of this product contains
lead and/or di (2-ethylhexyl) phthalate (DEHP),
chemicals known to the State of California
to cause cancer, and birth defects or other
reproductive harm. Wash hands after handling.
(California Health & Safety Code § 25249.5, et seq.)
SAVE THESE INSTRUCTIONS.

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SAFETYSETUPOPERATIONMAINTENANCE
Grounding
TO PREVENT ELECTRIC SHOCK AND DEATH
FROM INCORRECT GROUNDING WIRE CONNECTION:
Check with a qualified electrician if you are in doubt as to whether the outlet is properly
grounded. Do not modify the power cord plug provided with the compressor.
Never remove the grounding prong from the plug. Do not use the compressor if the power cord or plug is
damaged. If damaged, have it repaired by a service facility before use. If the plug will not fit the outlet,
have a proper outlet installed by a qualified electrician.
110-120 VAC Grounded Compressors:
Compressors with Three Prong Plugs
1. In the event of a malfunction or breakdown,
grounding provides a path of least resistance for
electric current to reduce the risk of electric shock.
This compressor is equipped with an electric
cord having an equipment-grounding conductor
and a grounding plug. The plug must be
plugged into a matching outlet that is properly
installed and grounded in accordance
with all local codes and ordinances.
2. Do not modify the plug provided –
if it will not fit the outlet, have the proper
outlet installed by a qualified electrician.
3. Improper connection of the equipment-grounding
conductor can result in a risk of electric shock.
The conductor with insulation having an outer
surface that is green with or without yellow
stripes is the equipment-grounding conductor.
If repair or replacement of the electric cord or
plug is necessary, do not connect the equipment-
grounding conductor to a live terminal.
4. Check with a qualified electrician or service
personnel if the grounding instructions are
not completely understood, or if in doubt as to
whether the compressor is properly grounded.
5. Use only 3-wire extension cords that have
3-prong grounding plugs and 3-pole receptacles
that accept the compressor’s plug.
6. Repair or replace damaged or
worn cord immediately.
125 VAC 3-Prong Plug and Outlet
(for up to 125 VAC and up to 15 A)
Grounding
Pin
7. This compressor is intended for use on a
circuit that has an outlet that looks like the one
illustrated above in 125 VAC 3-Prong Plug
and Outlet. The compressor has a grounding
plug that looks like the plug illustrated above
in 125 VAC 3-Prong Plug and Outlet.
8. The outlet must be properly installed and grounded
in accordance with all codes and ordinances.
9. Do not use an adapter to connect this
compressor to a different outlet.
Symbology
PSI Pounds per square inch of pressure
CFM Cubic Feet per Minute flow
SCFM Cubic Feet per Minute flow
at standard conditions
NPT National pipe thread, tapered
NPS National pipe thread, straight
Double Insulated
Canadian Standards Association
Underwriters Laboratories, Inc.
VAC Volts Alternating Current
AAmperes

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SAFETY SETUP OPERATION MAINTENANCE
Specifications
Electrical Rating 120VAC / 60Hz / 14A
(Dedicated circuit recommended)
Air Outlet Size 1/4″ -18 NPT
Air Pressure Shut-off 125 PSI
Restart 95 PSI
Air Tank Capacity 21 Gallons
Air Flow Capacity 4.7 CFM @ 90 PSI
5.8 CFM @ 40 PSI
Oil Capacity 5.6 oz.
Oil Type SAE 30W, non-detergent, Air Compressor Oil
(sold separately)
Sound Level 90 dB @ 3′
Instructions for putting into use
Read the ENTIRE IMPORTANT SAFETY INFORMATION section at the beginning of this
manual including all text under subheadings therein before set up or use of this product.
TO PREVENT SERIOUS INJURY FROM ACCIDENTAL OPERATION:
Turn the Power Switch “OFF” and unplug the Air Compressor from its electrical
outlet before assembling or making any adjustments to the compressor.
Note: For additional information regarding the parts listed in the following pages,
refer to the Assembly Diagram near the end of this manual.
Figure A: Functions
ON/OFF Power Lever
(On Pressure Switch (54))
Oil Sight
Glass
(33)
Pressure
Regulator
(74)
Safety
Valve
(73) Tank Pressure
Gauge (53)
Output
Pressure
Gauge (77)
Quick
Coupler (76)
- for attaching
in-line shutoff
valve, air
hose and tool
Drain
Valve (66)
OFF
ON
ON/OFF
Power
Lever
Tank Pressure
Gauge (53)
Safety
Valve
(73)
Output Pressure
Gauge (77)
Pressure
Regulator
(74)
Quick
Coupler
(76)
Pressure
Switch (54)
Figure B: Controls
248648

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SAFETYSETUPOPERATIONMAINTENANCE
Assembly
1.
Figure D Bolt (64)
Hex Nut (65)
Tank (70)
Wheel (63)
Screw (69)
Nut (24)
Foot Pad (67)
Washer (68)
Washer (64b)
Sleeve (64a)
Attach the Wheels (63) to the Tank (70),
using the Bolts (64), Washers (64b), Sleeves
(64a), and Hex Nuts (65). Attach the Foot
Pads (67) to the bottom of the Tank (70)
using the Screws (69) and Washers (68).
2.
Figure E
Handle (72)
Bolts (71)
Tank (70)
Slide the Handle (72) into the two slots
on the top of the Tank (70) and secure
in place with four Bolts (71).
3.
Figure F
Air Filter
(6)
Cylinder Head (7)
Thread the Air Filter (6) onto the
side of the Cylinder Head (7).
4. Break in the new Air Compressor as follows:
a. Turn the Power Switch off and unplug the unit.
Insert a male coupler (sold separately)
into the female Quick Coupler and fully
open all regulators and valves.
b. Plug in the Power Cord.
c. Turn the Power Switch ON.
d. Let the unit run for 30 minutes.
Air will expel freely through the Coupler.
e. Turn the Power Switch OFF.
f. Unplug the Power Cord and
remove the male coupler.
5. Connect a regulator valve, an inline shut off valve
and a 1/4″ NPT air hose to the Quick Coupler
(all sold separately). The air hose must be long
enough to reach the work area with enough extra
length to allow free movement while working.
Note: An in-line shutoff ball valve is an important
safety device because it controls the air supply even
if the air hose is ruptured. The shutoff valve should
be a ball valve because it can be closed quickly.
6. Depending on the tool which you will be using
with this compressor, you may need to incorporate
additional components, such as an in-line
oiler, a filter, or a dryer (all sold separately),
as shown on Figure G on page 8 and
Figure H on page 9. Consult your air
tool’s manual for needed accessories.

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SAFETY SETUP OPERATION MAINTENANCE
Figure G: Portable Air Supply Setup
G
A
E
E H
F
B
Non-lubricated Tools Lubricated Tools
A
B
C
C
DA
Description Function
A Air Hose Connects air to tool
B Filter Prevents dirt and condensation from damaging tool or workpiece
C Regulator Adjusts air pressure to tool D Lubricator (optional) For air tool lubrication
E Coupler and Plug Provides quick connection and release
F Leader Hose (optional) Increases coupler life
G Air Cleaner / Dryer (optional) Prevents water vapor from damaging workpiece
H Air Adjusting Valve (optional) For fine tuning airflow at tool

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SAFETYSETUPOPERATIONMAINTENANCE
Figure H: Stationary Air Supply Setup
N
L
L O
M
C C
Non-lubricated
Tools
Lubricated Tools
H
I
I
J
JKH
F
G
E
Slope
F
F
B B
A
A
CD
Description Function
A Vibration Pads For noise and vibration reduction
B Anchor Bolts Secures air compressor in place
C Ball Valve Isolates sections of system for maintenance D Isolation Hose For vibration reduction
EMain Air Line - 3/4″ minimum recommended Distributes air to branch lines
F Ball Valve To drain moisture from system
GBranch Air Line -1/2″ minimum recommended Brings air to point of use
H Air Hose Connects air to tool
I Filter Prevents dirt and condensation from damaging tool or workpiece
J Regulator Adjusts air pressure to tool
K Lubricator (optional) For air tool lubrication
L Coupler and Plug Provides quick connection and release
M Leader Hose (optional) Increases coupler life
N Air Cleaner / Dryer (optional) Prevents water vapor from damaging workpiece
O Air Adjusting Valve (optional) For fine tuning airflow at tool

Page 10 For technical questions, please call 1-888-866-5797. ITEM 61454
SAFETY SETUP OPERATION MAINTENANCE
Checking the Oil
1. Check the oil level before operation. Fill the Pump
Crankcase (39) with SAE 30W, non-detergent,
Air Compressor Oil (sold separately).
IMPORTANT: Running the Air Compressor with
the incorrect amount of oil will cause damage
to the equipment and void the warranty. To
prevent damage, do not use with overfilled or
low oil. Slowly fill to full line, wait 2 minutes
and fill back up to full line. Compressor
has small passages that will fill slowly.
2.
Oil Sight Glass (33)Crankcase Cover (31)
Tank (70)
OVERFILL
LOW
FULL
OIL LEVEL
Figure I: Oil Sight Glass
The oil level should be at the center of the “full”
level on the oil level sight glass, as shown in
Figure I. Add oil as needed to maintain this level.
Do not let the oil level go below the center dot
(LOW as shown above) and do not overfill the
oil so that it is above the center dot (OVERFILL
as shown above) on the sight glass.
3. To add oil:
a. Remove the Oil Plug (37).
b. Using a funnel to avoid spills, pour enough
oil into the Pump Crankcase (39) to reach
the “full” level in the Oil Sight Glass (33).
c. Replace the Oil Plug.
Cold Weather Operation
Premium quality 30-weight, non-detergent air
compressor oil (sold separately) is recommended
for use with this compressor. Start compressor
in heated area if outdoor temperatures drop
below 32° F. If this is not practical, drain out the
old pump oil and use SAE 10W Non-detergent Air
Compressor Oil in the pump crankcase instead
whenever the compressor’s temperature will fall
below 40°. Do not use multi-viscosity oil (such
as 10W-30), they leave carbon deposits on pump
components and lead to accelerated failure. Heavy
operation may require heavier viscosity oil.
4. If uncertain which oil to use for this compressor,
please call Harbor Freight Tools customer
service at 1-888-866-5797 for assistance.
5. Change the compressor oil after the first
hour of use to remove any debris.
CAUTION! TO PREVENT INJURY FROM BURNS:
Do not add or change the oil while
the compressor is in operation.
Allow the compressor to cool before replacing oil.

Page 11For technical questions, please call 1-888-866-5797.ITEM 61454
SAFETYSETUPOPERATIONMAINTENANCE
Operating Instructions
Read the ENTIRE IMPORTANT SAFETY INFORMATION section at the beginning of this
manual including all text under subheadings therein before set up or use of this product.
Compressor Area Set Up
1. Designate a work area that is clean and well-lit.
The work area must not allow access by
children or pets to prevent injury.
2. Locate the Compressor on a flat level surface to
ensure proper pump lubrication and to prevent
damage to the unit. Keep at least 12″ of space
around the unit to allow air circulation.
3. Route the power cord from the compressor
to the grounded wall outlet, along a safe path
without creating a tripping hazard or exposing
the power cord to possible damage.

Page 12 For technical questions, please call 1-888-866-5797. ITEM 61454
SAFETY SETUP OPERATION MAINTENANCE
General Operation
1. IMPORTANT: First, turn the Power Switch OFF.
This releases tank pressure and allows the motor
to start freely, without tripping the Circuit Breaker.
2. Close the Drain Valve by turning it clockwise.
3. Check for oil leaks and check the oil level
(See Checking the Oil).
4. Close the in-line Shutoff Valve between
the compressor and the air hose.
5. Plug the Air Compressor Power Cord into
a grounded 120 VAC electrical outlet.
6. Turn the Power Switch ON.
7. Allow the Air Compressor to build
up pressure until it cycles off.
Note: At the beginning of the day’s first use
of the Air Compressor, check for air leaks by
applying soapy water to connections while the
Air Compressor is pumping and after pressure cut-
out. Look for air bubbles. If air bubbles are present
at connections, tighten connections. Do not use the
Air Compressor unless all connections are air tight,
the extra air leaking out will cause the compressor to
operate too often, increasing wear on the compressor.
Note: As long as the Power Switch is ON, the operation
of the Air Compressor is automatic, controlled by an
internal pressure switch. The Compressor will turn on
automatically when the air pressure drops to 95 PSI,
and will turn off automatically when the
air pressure reaches 125 PSI.
WARNING! TO PREVENT SERIOUS
INJURY AND DEATH FROM
EXPLOSION:
Do not adjust the internal
pressure switch. Any change to the automatic
pressure levels may cause excess pressure to
accumulate, causing a hazardous situation.
8. Adjust the Air Compressor’s Pressure Regulator
so that the air output is enough to properly
power the tool, but the output will not exceed
the tool’s maximum air pressure at any time.
Turn the knob clockwise to increase the pressure
and counter-clockwise to decrease pressure.
Adjust the pressure gradually, while checking
the air output gauge to set the pressure.
9. Make sure the air tool’s throttle or switch is in the
off position. Connect the air tool to the air hose.
10. Open the in-line Shutoff Valve.
11. Use the air tool as needed.
12. After the job is complete, turn
the Power Switch OFF.
Note: Turn the switch off before
unplugging the compressor.
13. Unplug the Air Compressor.
14. Close the in-line Shutoff Valve.
15. Bleed air from the tool then disconnect the tool.
16. Turn the Drain Valve, at the bottom of the Tank,
two turns counterclockwise to release any
built-up moisture and the internal tank pressure.
Close the valve after moisture has drained out.
Do not remove the Drain Valve.
17. Clean, then store the Air Compressor indoors.

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SAFETYSETUPOPERATIONMAINTENANCE
Emergency Depressurization
If it is necessary to quickly depressurize the Compressor, turn the Power Switch OFF.
Then, pull on the ring on the Safety Valve to quickly release stored air pressure.
Automatic Shut off System
Reset
Button
Figure J: Reset Button
1. If the Compressor automatically shuts off
before reaching its normal cutoff pressure:
a. Shut off all tools.
b. Wait until the Compressor cools down
(about 10 minutes);
c. If the unit does not start up again on its own,
press the Reset Button to start the compressor;
d. Resume operation.
2. Possible causes of repeated automatic
shut off of the compressor are:
a. Using an extension cord that
is too long or narrow;
b. An air leak or open hose causing the compressor
to cycle too often and build up heat.
3. Correct any issues before further use to
avoid damage to the compressor.

Page 14 For technical questions, please call 1-888-866-5797. ITEM 61454
SAFETY SETUP OPERATION MAINTENANCE
Maintenance and Servicing
Procedures not specifically explained in this manual must
be performed only by a qualified technician.
TO PREVENT SERIOUS INJURY FROM ACCIDENTAL OPERATION:
Turn the Power Switch “OFF” and unplug the Compressor from its electrical outlet
before performing any inspection, maintenance, or cleaning procedures.
TO PREVENT SERIOUS INJURY FROM COMPRESSOR FAILURE:
Do not use damaged equipment. If abnormal noise or vibration occurs,
have the problem corrected before further use.
Cleaning, Maintenance, and Lubrication
1. BEFORE EACH USE, inspect the general
condition of the air compressor. Check for:
• loose hardware,
• misalignment or binding of moving parts,
• damaged belts,
• cracked or broken parts,
• damaged electrical wiring, and
• any other condition that may
affect its safe operation.
2. AFTER USE, wipe external surfaces of
the compressor with a clean cloth.
3. WARNING! If the supply cord of this
compressor is damaged, it must be replaced
only by a qualified service technician.
Maintenance Schedule
Following are general guidelines for maintenance checks of the Air Compressor.
Note: The environment in which the compressor is used, and the frequency of use can affect how often
you will need to check the Air Compressor components and perform maintenance procedures.
Daily:
a. Check oil level.
b. Check for oil leaks.
c. Make sure all nuts and bolts are tight.
d. Drain moisture from air tank.
e. Check for abnormal noise or vibration.
f. Check for air leaks.*
g. Inspect belt (if provided).
h. Wipe off any oil or dirt from the compressor.**
* To check for air leaks, apply soapy
water to joints while the Air Compressor is
pressurized. Look for air bubbles.
** To clean the compressor surface, wipe with
a damp cloth, using a mild detergent or mild solvent.
Weekly:
a. Inspect Air Filter.
b. Inspect Oil Breather Plug.
Monthly:
Inspect Safety Valve.
Every 6 months or 100 Operation Hours:
Replace Pump oil.***
*** Use SAE 30W, non-detergent,
Air Compressor Oil only (sold separately).

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SAFETYSETUPOPERATIONMAINTENANCE
Oil Maintenance
Check the oil periodically for clarity. Replace oil if it appears milky or if debris is present,
or every 6 months, or 100 hours of runtime, whichever comes first.
In harsh environments such as high heat or high humidity, you will need to replace the oil more frequently.
CAUTION! TO PREVENT INJURY FROM BURNS:
Allow Air Compressor to cool before changing the oil.
1. Place a container under the Drain Plug.
2. Remove the Oil Breather Plug to
allow air flow into the Pump.
3. Remove the Drain Plug, allowing the
oil to drain into the container.
4. When the oil is completely drained from the Pump,
replace the Drain Plug.
5. Fill the Pump with new SAE 30W, non-detergent,
Air Compressor Oil to the FULL level
on the Oil Sight Glass (5.6 oz.).
6. Replace and tighten the Oil Breather Plug.
7. Discard the old oil according to local,
state and federal regulations.
Draining Moisture from the Tank
The Drain Valve is located under the Tank.
It must be used daily to release all trapped air
and moisture from the Tank. This will eliminate
condensation which can cause tank corrosion.
CAUTION! Do not open the Drain Valve so
that more than four threads are showing.
1. Turn the Power switch of the compressor off.
2. Place a collection pan under the Drain Valve.
3. Unthread the Drain Valve two or three turns ONLY.
4. When all the pressure and moisture is released,
close the Drain Valve. Figure K: Drain Valve Operation
Counterclockwise
Drain Valve Open
Clockwise
Drain Valve Closed
Inside Compressor
Compressor Wall
Knob
To open the Drain Valve, turn the knob on the
bottom of the Compressor counterclockwise.
To close the Drain Valve, turn the knob on the
bottom of the compressor clockwise until you feel
tension and the knob is down as far as it can go.
Air Filter Maintenance
Check the Air Filter weekly to see if it needs replacement.
If working in dirty environments, you may need to replace the filter more often.
1. Remove the Cover.
2. Remove the Air Filter.
3. Replace with a new Air Filter.
4. Replace the Cover.

Page 16 For technical questions, please call 1-888-866-5797. ITEM 61454
SAFETY SETUP OPERATION MAINTENANCE
Troubleshooting
Problem Possible Causes Likely Solutions
Compressor does
not start or restart
1. Tank(s) already pressurized.
2. Power cord not plugged in properly.
3. Incorrect power supply.
4. No power at outlet.
5. Thermal overload switch tripped.
6. Building power supply circuit tripped or
blown fuse.
7. Cord wire size is too small or cord is too
long to properly power compressor.
8. Compressor needs service.
1. No problem. Compressor will start when needed.
2. Check that cord is plugged in securely.
3. Check that circuit matches compressor requirements.
4. Reset circuit breaker, or have outlet
serviced by a qualified technician.
5. Turn off Compressor and wait for it to cool down.
Press reset button. Resume operation.
6. Reset circuit or replace fuse. Check for low
voltage conditions. It may be necessary to
disconnect other electrical appliances from the
circuit or move the compressor to its own circuit.
7. Use larger diameter or shorter extension cord or
eliminate extension cord. See Recommended Wire
Gauge for Extension Cords in Safety section.
8. Have unit inspected by a qualified technician.
Compressor builds
pressure too slowly
1. Incorrect power supply.
2. Crankcase oil overfilled or oil too thick.
3. Working environment too cold.
4. Safety valve leaking.
5. Loose fittings.
1. Check that circuit matches compressor requirements.
2. Drain oil and refill to proper level
with recommended oil.
3. Move compressor to a warmer location.
Check that recommended oil is in crankcase.
4. Listen for air leaking from valve.
If leaking, replace with identical valve with same rating.
DO NOT SEAL OR TAMPER WITH SAFETY VALVE.
5. Reduce air pressure, then check all fittings with
a soap solution for air leaks and tighten as needed.
Do not overtighten.
Compressor not
building enough
air pressure
1. Air filters need cleaning/replacing.
2. Check Valve needs service.
3. Compressor not large enough for job.
4. Loose fittings.
5. Hose or hose connections too narrow.
6. Crankcase oil too thick.
7. High altitude reducing air output.
1. Check inlet and outlet filters.
Clean and/or replace as needed.
2. Have technician clean or replace, as needed.
3. Check if accessory CFM is met by Compressor.
If Compressor cannot supply enough air flow (CFM),
you need a larger Compressor.
4. Reduce air pressure, then check all fittings with
a soap solution for air leaks and tighten as needed.
Do not overtighten.
5. Replace with wider hose and/or hose connections.
6. Drain oil and refill to proper level
with recommended oil.
7. Higher altitudes require compressors
with greater output.
High Oil
Consumption
1. Crankcase oil too thin.
2. Unit not on level surface.
3. Crankcase vent clogged.
1. Drain oil and refill to proper level
with recommended oil.
2. Reposition unit on a level surface.
3. Clean Crankcase vent.
Follow all safety precautions whenever diagnosing or servicing the compressor.
Disconnect power supply before service.

Page 17For technical questions, please call 1-888-866-5797.ITEM 61454
SAFETYSETUPOPERATIONMAINTENANCE
Problem Possible Causes Likely Solutions
Overheating 1. Air filters need cleaning/replacing.
2. Crankcase oil too thin or incorrect type.
3. Crankcase oil level too low.
4. Unusually dusty environment.
5. Extension cord used.
6. Unit not on level surface.
1. Check inlet and outlet filters.
Clean and/or replace as needed.
2. Drain oil and refill to proper level
with recommended oil.
3. Add oil to proper level, check for leaks.
4. Clean and/or replace filters more often or
move unit to cleaner environment.
5. Eliminate extension cord.
6. Reposition unit on a level surface.
Compressor
starts and stops
excessively
1. Loose fittings.
2. Compressor not large enough for job.
1. Reduce air pressure, then check all fittings with a soap
solution for air leaks and tighten as needed.
Do not overtighten.
2. Check if accessory CFM is met by Compressor.
If Compressor doesn’t reach accessory
CFM, you need a larger Compressor.
Excessive noise 1. Crankcase overfilled with oil or oil
is incorrect thickness or type.
2. Crankcase oil level too low.
3. Loose or damaged belt guard.
4. Loose fittings.
5. Unit not on level surface.
1. Drain oil and refill to proper level
with recommended oil.
2. Add oil to proper level, check for leaks.
3. Replace belt guard.
4. Reduce air pressure, then check all fittings with a soap
solution for air leaks and tighten as needed.
Do not overtighten.
5. Reposition unit on a level surface.
Moisture in
discharge air
Too much moisture in air. Install inline air filter/dryer, and/or relocate
to less humid environment.
Oil in discharge air 1. Crankcase oil too thin or
crankcase overfilled with oil.
2. Crankcase vents clogged.
1. Drain oil and refill to proper level
with recommended oil.
2. Clean Crankcase vents.
Safety Valve “pops” Safety valve needs service. Pull on test ring of safety valve. If it still pops, replace.
Air leaks from
pump or fittings
Loose fittings. Reduce air pressure, then check all fittings with a soap
solution for air leaks and tighten as needed.
Do not overtighten.
Air leaks from tank Defective or rusted tank. Have tank replaced by a qualified technician.
Drain moisture from tank daily to prevent future corrosion.
Follow all safety precautions whenever diagnosing or servicing the compressor.
Disconnect power supply before service.
Troubleshooting (cont.)
PLEASE READ THE FOLLOWING CAREFULLY
THE MANUFACTURER AND/OR DISTRIBUTOR HAS PROVIDED THE PARTS LIST AND ASSEMBLY DIAGRAM
IN THIS MANUAL AS A REFERENCE TOOL ONLY. NEITHER THE MANUFACTURER OR DISTRIBUTOR
MAKES ANY REPRESENTATION OR WARRANTY OF ANY KIND TO THE BUYER THAT HE OR SHE IS
QUALIFIED TO MAKE ANY REPAIRS TO THE PRODUCT, OR THAT HE OR SHE IS QUALIFIED TO REPLACE
ANY PARTS OF THE 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 PARTS
THERETO, OR ARISING OUT OF HIS OR HER INSTALLATION OF REPLACEMENT PARTS THERETO.

Page 18 For technical questions, please call 1-888-866-5797. ITEM 61454
SAFETY SETUP OPERATION MAINTENANCE
Parts List and Diagram
Parts List
Record Product’s Serial Number Here:
Note: If product has no serial number, record month and year of purchase instead.
Note: Some parts are listed and shown for illustration purposes only,
and are not available individually as replacement parts.
Part Description Qty
1 Cover 1
2 Elbow 1
3 Start Valve 1
4 Spring Washer M6 8
5 Screw M6 x 50 4
6 Air Filter 1
7 Cylinder Head 1
8 Head Gasket 1
9 Valve Plate 2
10 Metal Gasket 1
11 Valve 2
12 Valve Plate Gasket 1
13 Cylinder 1
14 Bolt M8 x 30 2
15 Spring Washer M8 3
16 Cylinder Gasket 1
17 Pin Ø 13 x 44 1
18 Compression Ring 2
19 Oil Ring 1
20 Wrist Pin Retainer 2
21 Piston 1
22 Connecting Rod 1
23 Screw M6 x 20 5
24 Hex Nut M6 3
25 Crank Shaft 1
26 O-Ring 2
26a Zip Tie 1
27 Capacitor 1
28 Screw M8 x 20 1
29 Capacitor Bracket 1
30 Hex Nut M8 1
31 Crank Case Cover 1
32 O-Ring 1
33 Oil Sight Glass 1
34 O-Ring 1
35 Drain Plug M5 x 10 1
36 O-Ring 1
37 Oil Plug 1
38 Crankcase Cover Gasket 1
39 Pump Crankcase 1
40 Washer M5 10
41 Screw M5 x 16 10
Part Description Qty
42 Manual Overload Protector 1
43 Oil Seal 1
44 Bearing 1
45 Rotator 1
46 Bearing 1
47 Stator 1
48 Automatic Thermal Protector 1
49 End Cover 1
50 Fan 1
51 Circlip 1
51a Plain Washer 5 4
51b Spring Washer 5 4
51c Bolt M5 x 130 4
52 Connector 1
53 Tank Pressure Gauge 1
54 Pressure Switch 1
55 Unloader Tube 1
56 Nut 1
57 Ferrule 1
58 Check Valve 1
59 Ferrule 2
60 Nut 2
61 Exhaust Tube 1
62 Cooling Fin 1
63 Wheel 2
64 Bolt M12 x 55 2
64a Sleeve 2
64b Washer 12 2
65 Hex Nut M12 2
66 Drain Valve 1
67 Foot Pad 2
68 Washer 2
69 Screw M6 x 25 2
70 Tank 1
71 Bolt M6 x 10 4
72 Handle 1
73 Safety Valve 1
74 Pressure Regulator 1
75 Motor Cord 1
76 Quick Coupler 1
77 Output Pressure Gauge 1
78 Plug 1

Page 19For technical questions, please call 1-888-866-5797.ITEM 61454
SAFETYSETUPOPERATIONMAINTENANCE
Assembly Diagram
a
a
b
b

Limited 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 verifies 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 specific legal rights and you may also have other rights which vary from state to state.
3491 Mission Oaks Blvd. • PO Box 6009 • Camarillo, CA 93011 • 1-888-866-5797