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.
GAL
30
gas powered two-stage
air compressor
REV 15e
Using a generator indoors CAN
KILL YOU IN MINUTES.
Generator exhaust contains
carbon monoxide. This is a poison
you cannot see or smell.
NEVER use inside
a home or garage,
EVEN IF doors and
windows are open.
When unpacking, make sure that the product is intact
and undamaged. If any parts are missing or broken,
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.
SymbolProperty or Statement
RPM
HP
Revolutions Per Minute
Horsepower
WARNING marking concerning Risk
of Eye Injury. Wear ANSI-approved
safety goggles with side shields.
SymbolProperty or Statement
WARNING marking concerning
Risk of Respiratory Injury.
Operate engine OUTSIDE and far away
from windows, doors, and vents.
WARNING marking concerning
Risk of Explosion.
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.
Set up Precautions
1. Gasoline fuel and fumes are flammable, and
potentially explosive. Use proper fuel storage
and handling procedures. Do not store fuel
or other flammable materials nearby.
2. Have multiple ABC class fire extinguishers nearby.
3. Operation of this equipment may create sparks
that can start fires around dry vegetation. A spark
arrestor may be required. The operator should
contact local fire agencies for laws or regulations
relating to fire prevention requirements.
4. Set up and use only on a flat, level,
well-ventilated surface.
5. Use only lubricants and fuel recommended
in the engine manual or in the
Specifications chart of this manual.
6. Wear ANSI-approved safety goggles, heavy-duty
work gloves, and dust mask/respirator during set up.
Engine Precautions
Follow engine precautions and instructions in the included engine instruction manual.
Operating Precautions
1. CARBON MONOXIDE HAZARD
Using an engine indoors CAN KILL
YOU IN MINUTES.
Engine exhaust contains carbon
monoxide. This is a poison you cannot see or smell.
NEVER use inside a home or garage, EVEN IF
doors and windows are open.
Only use OUTSIDE and far away from windows,
doors, and vents.
2. Keep children away from the equipment,
especially while it is operating.
3. Fire Hazard! Do not fill gas tank while
Compressor engine is running. Do not
operate if gasoline has been spilled. Clean
spilled gasoline before starting engine. Do
not operate near pilot light or open flame.
4. Do not touch Compressor engine during
use. Let engine cool down after use.
5. Never store fuel or other flammable
materials near the Compressor engine.
6. Only use a suitable means of transport and
lifting devices with sufficient weight bearing
capacity when transporting the Compressor.
7. Secure the Compressor on transport vehicles to
prevent the tool from rolling, slipping, and tilting.
8. Industrial applications must follow
OSHA requirements.
9. Do not leave the equipment unattended when it is
running. Turn off the equipment (and remove safety
keys, if available) before leaving the work area.
10. Wear ANSI-approved safety glasses, hearing
protection, and NIOSH-approved dust mask/
respirator under a full face shield along
with steel-toed work boots during use.
11. People with pacemakers should consult their
physician(s) before use. Electromagnetic fields
in close proximity to a heart pacemaker could
cause pacemaker interference or pacemaker
failure. Caution is necessary when near
the engine’s magneto or recoil starter.
12. Use only accessories that are recommended
by Harbor Freight Tools for your model.
Accessories that may be suitable for one
piece of equipment may become hazardous
when used on another piece of equipment.
13. Do not operate in explosive atmospheres,
such as in the presence of flammable
liquids, gases, or dust. Gasoline-powered
engines may ignite the dust or fumes.
14. Stay alert, watch what you are doing and
use common sense when operating this
piece of equipment. Do not use this piece
of equipment while tired or under the
influence of drugs, alcohol or medication.
15. Do not overreach. Keep proper footing and
balance at all times. This enables better control
of the equipment in unexpected situations.
16. Dress properly. Do not wear loose clothing or
jewelry. Keep hair, clothing and gloves away
from moving parts. Loose clothes, jewelry or
long hair can be caught in moving parts.
17. Parts, especially exhaust system components,
get very hot during use. Stay clear of hot parts.
18. Do not cover the engine or
equipment during operation.
19. Keep the equipment, engine, and
surrounding area clean at all times.
20. Use the equipment, accessories, etc., in
accordance with these instructions and in the
manner intended for the particular type of
equipment, taking into account the working
conditions and the work to be performed. Use of
the equipment for operations different from those
intended could result in a hazardous situation.
21. Do not operate the equipment with known
leaks in the engine’s fuel system.
22. WARNING: This product contains or, when
used, produces 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.)
23. 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.)
SAFETYSETUPOPERATIONMAINTENANCE
24. When spills of fuel or oil occur, they must be
cleaned up immediately. Dispose of fluids and
cleaning materials as per any local, state, or
federal codes and regulations. Store oil rags in
a bottom-ventilated, covered, metal container.
Service Precautions
25. Keep hands and feet away from moving parts. Do
not reach over or across equipment while operating.
26. Before use, check for misalignment or binding
of moving parts, breakage of parts, and any
other condition that may affect the equipment’s
operation. If damaged, have the equipment serviced before using. Many accidents are
caused by poorly maintained equipment.
27. Use the correct equipment for the application.
Do not modify the equipment and do not use the
equipment for a purpose for which it is not intended.
1. Before service, maintenance, or cleaning:
a. Turn the engine switch to its “OFF” position.
b. Allow the engine to completely cool.
c. Then, remove the spark plug
cap from the spark plug.
2. Keep all safety guards in place and in
proper working order. Safety guards include
muffler, air cleaner, mechanical guards,
and heat shields, among other guards.
3. Do not alter or adjust any part of the
equipment or its engine that is sealed by the
manufacturer or distributor. Only a qualified
service technician may adjust parts that may
increase or decrease governed engine speed.
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 maximum stated 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 use the air hose to move the compressor.
6. Drain Tank daily and after use. Internal
rust causes tank failure and explosion.
4. Wear ANSI-approved safety goggles,
heavy-duty work gloves, and dust
mask/respirator during service.
5. Maintain labels and nameplates on
the equipment. These carry important
information. If unreadable or missing, contact
Harbor Freight Tools for a replacement.
6. Have the equipment serviced by a qualified repair
person using only identical replacement parts.
This will ensure that the safety of the equipment
is maintained. Do not attempt any service or
maintenance procedures not explained in this
manual or any procedures that you are uncertain
about your ability to perform safely or correctly.
7. Store equipment out of the reach of children.
8. Follow scheduled engine and
equipment maintenance.
7. Add correct amount of compressor oil before
first use and every use. Operating with the
incorrect amount of oil causes permanent
damage and voids warranty. To prevent
damage, do not use with overfilled or low oil.
8. Compressor head gets hot during operation.
Do not touch it or allow children nearby
during or immediately following operation.
9. Release the pressure in the storage
tank before moving.
10. The use of accessories or attachments not
recommended by the manufacturer may
result in a risk of injury to persons.
11. All air line components, including hoses, pipe,
connectors, filters, etc., must be rated for a minimum
working pressure of 125 PSI, or 150% of the
maximum system pressure, whichever is greater.
Note: Engine specifications are found in the engine manual supplied with this equipment.
Engine Controls
Belt Guard Frame (122) &
Belt Guard Cover (130)
ON/OFF
Switch
Tank
Pressure
Gauge (97)
Pilot Valve
Pump Safety Valve (91)
SAFETYSETUPOPERATIONMAINTENANCE
Air Filter
Assembly
(84)
Oil Sight
Glass (19)
Air Outlet (106)
1. Belt Guard - The Belt Guard encloses the pulleys and drive belts.
It protects the user from the moving parts and allows the
large pulley to direct cooling air to the Air Pump.
2. Oil Sight Glass - The oil sight glass shows proper level of
the oil. Oil level should be at center of Sight Glass.
3. Tank Drain Valve - The Air Tank Drain Valve allows moisture
to be removed from the tank to prevent corrosion.
4. Safety Valve - The Safety Valve automatically releases
air if the Air Tank pressure exceeds the preset maximum.
In an emergency, the ring can be pulled to relieve tank air pressure.
There is one safety valve on the pump and one on the tank.
5. Air Outlet - An air hose attaches to this valve.
Air pressure required by tools is set by an air pressure regulator.
6. Air Storage Tank - The Air Tank is where air
pressurized by the Air Pump is stored for use.
7. Tank Pressure Gauge - The Air Tank Pressure
Gauge displays the air pressure in the tank.
8. Pilot Valve - Open the Pilot Valve before starting the engine.
It relieves resistance on the engine to make starting possible.
Rotate the pin so it is vertical to open it. Once the engine is running,
close the Pilot Valve so the Compressor can build up pressure.
The emission control system for this Compressor’s Engine is warranted for standards set by the U.S. Environmental
Protection Agency and by the California Air Resources Board (also known as CARB). For warranty information,
refer to the engine manual.
SAFETYSETUPOPERATIONMAINTENANCE
Mounting to a Truck bed
1. Before mounting, if needed, reinforce the area with plywood or steel plating.
2. With assistance, move the compressor to the truck bed location and mark the floor of the truck
bed through the holes in the compressor’s feet. Check for any hidden wiring or cables and
adjust the location for the holes as needed. Then, temporarily set the compressor aside.
3. Drill the four 1/2″ diameter holes through the truck bed and any reinforcing materials.
4. Set the compressor back in place, and align the foot holes with the pre-drilled holes. Use four 1/2″
diameter, bolts, washers and lock washers (all not included) to secure the compressor in place.
Air Filter
Assembly (84)
Wing NutConnector
Assembly
To install the Air Filter Assembly (84), fit the Connector
into the Air Filter Assembly and slide the assembly into
the hole on the side of the First Stage Cylinder Head (61).
Secure in place with the Wing Nut.
Break-In Compressor
Break in the new Air Compressor as follows:
a. Make sure the engine is off. Open the air outlet valve on the left side of the tank.
b. Check all fluid levels in the engine and pump.
c. Start the engine following the General Operating Instructions.
d. Let the unit run for 30 minutes. Air will expel freely through the Coupler.
e. Turn OFF the engine.
f. Remove the male coupler.
Second Stage
Cylinder Head
(21)
First Stage
Cylinder Head
(61)
Connection
1. Connect a regulator valve, an in-line shut off valve and a 1/2″ NPT air hose
(all sold separately) to the Quick Coupler. 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.
2. 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). Consult your air tool’s manual
for needed accessories. See Typical Air Line Setup charts on the following pages.
This is a truckbed compressor, so use the portable setup as a model.
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.
Using the Compressor
Inspect Compressor, engine, pump and equipment looking for damaged, loose, and missing parts
before set up and starting. If any problems are found, do not use equipment until fixed properly.
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.
Before starting the Compressor:
a. Follow the Set Up Instructions in the equipment manual to prepare the equipment.
b. Follow the Set Up Instructions in the Engine manual to prepare the engine.
c. Inspect all components of the setup. Make sure all nuts and bolts are tight.
d. Fill the Engine with the proper amount and type of both fuel and oil.
e. Fill the Compressor Pump with compressor oil following
the Maintenance Instructions in this manual.
To Start and Use the Compressor
SAFETYSETUPOPERATIONMAINTENANCE
1. Close the Drain Valve (137) by turning the lever
up so that it is perpendicular to the valve.
2. Close the in-line Shutoff Valve between
the compressor and the air hose.
3. Open the Pilot Valve by rotating it to a vertical position.
5. To start a cold engine, move the Choke to the CHOKE
(start/closed) position.
To restart a warm engine, leave the
Choke in the RUN position.
SAFETYSETUPOPERATIONMAINTENANCE
5
6. For MANUAL START
a. Turn the Engine Switch to ON.
ON
OFFSTART
b. Grip the Starter Handle of the Engine loosely and
pull it slowly several times to allow the gasoline
to flow into the Engine’s carburetor. Then pull
the Starter Handle gently until resistance is felt.
Allow Cable to retract fully and then pull it quickly.
Repeat until the engine starts. Note: Do not let
the Starter Handle snap back against the engine.
Hold it as it recoils so it doesn't hit the engine.
ON
For ELECTRIC START
Turn the Engine Switch to START.
Note: To prolong starter life, use short starting
cycles (5 seconds maximum). Then wait one
minute before attempting to start again.
ON
OFFSTART
START
7. Allow the Engine to run for several seconds.
Then, if the Choke lever is in the CHOKE position,
move the Choke Lever very slowly to its RUN position.
Note: Moving the Choke Lever too fast could kill the engine.
8. Close the Pilot Valve by rotating
it to a horizontal position.
9. When the Gas Engine is started and running, the
compressor Pump starts compressing air into the Air
Tank. Open the in-line Shutoff Valve and adjust the
Pressure Regulator (sold separately) 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 counterclockwise to decrease pressure.
Adjust the pressure gradually, while checking
the air output gauge to set the pressure.
IMPORTANT: Allow the engine to run for five minutes with no load
after each start-up so that the engine can stabilize.
Maintenance Break-in Period:
Breaking-in the engine will help to ensure proper equipment and engine operation.
The maintenance break-in period will last about 20 hours of use. After this period, change the engine oil.
Under normal operating conditions, subsequent maintenance follows the schedule
explained in the MAINTENANCE AND SERVICING section.
Note: When maximum tank pressure is reached, the compressor automatically disengages, and the engine
RPM drops down to idle speed. The engine remains at idle until Air Tank pressure falls to a preset level.
The Gas Engine will then accelerate and air pressure once again begins to build up in the Air Tank.
Note: As long as the engine is running, the operation of the Air Compressor
is automatic, controlled by an internal pressure switch.
9
SAFETYSETUPOPERATIONMAINTENANCE
IMPORTANT: The internal pressure switch is not user adjustable; do not make changes to the
air pressure settings of the internal pressure switch. Any change to the automatic pressure
levels may cause excess pressure to accumulate, causing a hazardous situation.
Note: Depressurization - If it is necessary to quickly depressurize the Compressor, turn OFF the engine.
Then, pull on the ring on the tank Safety Valve to release stored air pressure.
10. Use the air tool as needed.
11. After the job is complete, turn OFF the engine.
To stop the engine in an emergency,
turn the Engine Switch off.
Under normal conditions, use the following procedure:
a. Turn the Engine Switch off.
b. Close the Fuel Valve.