Central Pneumatic CentralPneumatic 68064 Installation manual

2 HP, 4 GALLON, 125 PSI
TWIN TANK AIR COMPRESSOR
Model 68064
SET UP 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©2010 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.
For technical questions or replacement parts, please call 1-800-444-3353.

Page 2 For technical questions, please call 1-800-444-3353. SKU 68064
CONTENTS
IMPORTANT SAFETY
INFORMATION ............................ 3
GENERAL COMPRESSOR
SAFETY WARNINGS.......................3
AIR COMPRESSOR SAFETY
WARNINGS......................................5
GROUNDING ................................. 6
110-120 V~ GROUNDED
COMPRESSORS:
COMPRESSORS WITH THREE
PRONG PLUGS...............................6
SYMBOLOGY.....................................7
SPECIFICATIONS.......................... 8
UNPACKING .................................. 8
INSTRUCTIONS FOR PUTTING
INTO USE .................................... 8
FUNCTIONS .......................................8
WORK PIECE AND WORK AREA
SET UP ............................................9
ASSEMBLY.........................................9
SET UP ...............................................9
CHECKING THE OIL........................10
GENERAL OPERATING
INSTRUCTIONS ........................ 11
EMERGENCY
DEPRESSURIZATION................... 12
AUTOMATIC SHUT OFF SYSTEM ..12
MAINTENANCE AND
SERVICING ............................... 13
CLEANING, MAINTENANCE, AND
LUBRICATION ............................... 13
MAINTENANCE SCHEDULE...........13
OIL MAINTENANCE.........................14
DRAINING MOISTURE FROM THE
TANK..............................................14
AIR FILTER MAINTENANCE ...........15
TROUBLESHOOTING......................16
PARTS LIST................................. 18
ASSEMBLY DIAGRAM................ 19
LIMITED 1 YEAR / 90 DAY
WARRANTY .............................. 20

Page 3For technical questions, please call 1-800-444-3353.SKU 68064
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.
IMPORTANT SAFETY
INFORMATION
In this manual, on the labeling,
and all other information
provided with this product:
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.
DANGER indicates
a hazardous
situation which, if not
avoided, will result in death or
serious injury.
WARNING
indicates a
hazardous situation which, if
not avoided, could result in
death or serious injury.
CAUTION, used
with the safety
alert symbol, indicates a
hazardous situation which, if
not avoided, could result in
minor or moderate injury.
NOTICE is used to
address practices
not related to personal injury.
CAUTION, without
the safety alert
symbol, is used to address
practices not related to
personal injury.
General Compressor Safety
Warnings
WARNING Read all safety
warnings and instructions.
Failure to follow the warnings and
instructions may result in electric
shock, re and/or serious injury.
Save all warnings and
instructions for future reference.
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 ammable 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 a grounded
compressor. Standard plugs and

Page 4 For technical questions, please call 1-800-444-3353. SKU 68064
matching outlets will reduce risk of
electric shock.
b.Do not expose the 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 pulling or 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 inuence
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 eye
protection. Safety equipment such
as a dust mask, non-skid safety
shoes, hard hat, or hearing protection
used for appropriate conditions will
reduce personal injuries.
c. Prevent unintentional starting.
Ensure the switch is in the off-
position before connecting to
power source or moving the
compressor.
d.Only use safety equipment
that has been approved by an
appropriate standards agency.
Unapproved safety equipment may
not provide adequate protection. Eye
protection must be ANSI-approved
and breathing protection must be
NIOSH-approved for the specic
hazards in the work area.
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 of the compressor
before making any adjustments,
changing accessories, or storing
it. 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. Following
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.

Page 5For technical questions, please call 1-800-444-3353.SKU 68064
5. Service
a.Have your compressor serviced
by a qualied repair person using
only identical replacement parts.
This will ensure that the safety of the
compressor is maintained.
Air Compressor Safety Warnings
1. Risk of re or explosion - Do not
spray ammable liquid in a conned
area or towards a hot surface. Spray
area must be well-ventilated. Do not
smoke while spraying or spray where
spark or ame 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 maximum
stated pressure of attachment.
3. Risk of injury - Do not direct air
stream at people or animals.
4. To reduce the risk of electric shock,
do not expose to rain. Store indoors.
5. Wear ANSI-approved safety goggles
during use.
6. Do not use to supply breathing air.
7. Do not use the air hose to move the
compressor.
8. Drain Tank daily and after use.
Internal rust causes tank failure and
explosion.
9. Add correct amount of compressor
oil before rst use and every
use. Operating with the incorrect
amount of oil causes permanent
damage and voids warranty. To
prevent damage, do not use with
overlled or low oil. Slowly ll to
full line, wait 2 minutes and ll
back up to full line. Compressor
has small passages that will ll
slowly.
10. Do not remove the Pressure Switch
(63) cover or adjust the internal
components.
11. Compressor head gets hot during
operation. Do not touch it or allow
children nearby during or immediately
following operation.
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, lters, etc.,
must be rated for a minimum working
pressure of 125 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:
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 14 12
10.1 – 12 16 16 14 12
12.1 – 16 14 12 Do not use.
TABLE A

Page 6 For technical questions, please call 1-800-444-3353. SKU 68064
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 ll to marked level if
needed.
20. People with pacemakers should
consult their physician(s) before
use. Electromagnetic elds 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 birth defects (or
other reproductive harm). (California
Health & Safety code § 25249.5, et
seq.)
22. 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.
SAVE THESE
INSTRUCTIONS.
GROUNDING
TO PREVENT
ELECTRIC SHOCK
AND DEATH FROM
INCORRECT GROUNDING
WIRE CONNECTION:
Check with a qualied
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
t the outlet, have a proper
outlet installed by a qualied
electrician.
110-120 V~ Grounded
Compressors: Compressors with
Three Prong Plugs
1. In the event of a malfunction or
breakdown, grounding provides a

Page 7For technical questions, please call 1-800-444-3353.SKU 68064
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 t the outlet, have the
proper outlet installed by a qualied
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 qualied 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.
120 V~ 3-Prong Plug and Outlet
(for up to 120 V~ and up to 15.5 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 120 V~ 3-Prong Plug and Outlet.
The compressor has a grounding
plug that looks like the plug illustrated
above in 120 V~ 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
Canadian Standards Association
V~ Volts Alternating Current
AAmperes
n0xxxx/min. No Load Revolutions per Minute
(RPM)

Page 8 For technical questions, please call 1-800-444-3353. SKU 68064
SPECIFICATIONS
Electrical
Requirements 120 V~ / 60 Hz / 2 HP
Amperage 14A
Motor Speed 3450 RPM
Phase Single
Air Outlet Size 1/4”-18 NPT
Air Pressure Auto Shut-Off @ 125 PSI
Restart @ 95 PSI
Measured Air Tank
Capacity 4 Gallons
Stated Air Flow
Capacity
3.7 SCFM @ 90 PSI
5 SCFM @ 40 PSI
Oil Capacity 5.6 oz. (165ml)
Oil Type
SAE 30W non-detergent
Air Compressor Oil
(Sold separately)
(SKU 95048)
Decibel Level 90 dB @ 1m
UNPACKING
When unpacking, make sure that the
item is intact and undamaged. If any parts
are missing or broken, please call Harbor
Freight Tools at 1-800-444-3353 as soon
as possible.
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 Lever “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.
Functions
Figure 1
Oil Sight
Glass
(35)
Pressure
Regulator
(85)
Tank Pressure
Gauge (83)
Output Pressure
Gauge (86)
Quick Coupler (84) -
For attaching in-line
shutoff valve, air
hose and tool
Drain Valve (71),
under bottom Tank
Tank Pressure
Gauge (83)
Output Pressure
Gauge (86)
Pressure
Regulator (85)
Quick Coupler
(84)
Control Panel
ON
OFF
ON/OFF
Power Lever Safety
Valve
(64)
Controls on side of unit

Page 9For technical questions, please call 1-800-444-3353.SKU 68064
Work Piece and Work 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 at
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.
Assembly
1.
Figure 2
Bolt (74)
Washer (75)
Wheel (73)
Tank (59)
Bushing (76)
Frame
Nut (77)
To attach the Wheels (73) to the
frame:
a. Slide the Washer (75), Wheel (73)
and Bushing (76) onto the Bolt (74).
b. Slide the Bolt through the frame hole
and secure in place with the Nut
(77).
c. Repeat steps 2 and 3 for the other
Wheel.
Set Up
1. Break in the new Air Compressor as
follows:
a. Check the oil level before operation.
Fill the Pump Crankcase (41) with
approximately 5.6 oz. of premium
quality SAE 30-weight, non-
detergent air compressor oil.
b. Make sure the Power Lever is OFF
and the unit is unplugged. Insert a
male coupler (sold separately) into
the Female Quick Coupler (84) and
fully open all regulators and valves.
c. Plug in the Power Cord.
d. Turn the Power Lever ON.
e. Let the unit run for 30 minutes. Air
will expel freely through the Coupler.
f. Turn the Power Lever OFF.
g. Unplug the Power Cord and remove
the male coupler.

Page 10 For technical questions, please call 1-800-444-3353. SKU 68064
2.
Quick
Coupler
Sample Air Line Setup
Regulator with
Pressure Gauge
Quick
Coupler Air Hose
on Reel
Shut
Off
Valve
FilterOiler
Coupler
Plug
Tool
Air
Compressor
Coupler
Plug
Connect a regulator valve, an in-line
shut off valve and a 1/4” NPT air hose
(all sold separately) to the Quick
Coupler (84). 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.
3. 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 lter, or a dryer (all sold separately).
Consult your air tool’s manual for
needed accessories.
Checking the Oil
1. Check the oil level before operation.
Fill the Pump Crankcase (41) with
approximately 5.6 oz. of premium
quality SAE 30-weight, non-detergent
air compressor oil.
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 overlled or low
oil. Slowly ll to full line, wait 2
minutes and ll back up to full line.
Compressor has small passages
that will ll slowly.
2.
Oil Sight Glass (35)Crankcase Cover (33)
Wheel (73)
Figure 3
OVERFILL
LOW
FULL
OIL LEVEL
The oil level should be at the center
of the “full” level on the oil level sight
glass, as shown in Figure 3. 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 overll 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 (39).
b. Using a funnel to avoid spills, pour
enough oil into the Pump Crankcase
(41) to reach the “full” level in the Oil
Sight Glass (35).
c. Replace the Oil Plug.
Cold Weather Operation
Premium quality 30-weight, non-
detergent air compressor oil (sold
separately) is recommended for