JobSmart 3901726 Quick reference guide

3901726
4 Gallon Air Compressor
Assembly & Operating Instructions
READ ALL INSTRUCTIONS AND WARNINGS BEFORE USING THIS PRODUCT.
This manual provides important information on proper operation & maintenance. Every effort has been
made to ensure the accuracy of this manual. These instructions are not meant to cover every possible
condition and situation that may occur. We reserve the right to change this product at any time
without prior notice.
IF THERE IS ANY QUESTION ABOUT A CONDITION BEING SAFE OR UNSAFE, DO NOT
OPERATE THIS PRODUCT!
HAVE QUESTIONS OR PROBLEMS? DO NOT RETURN THIS PRODUCT TO THE
RETAILER - CONTACT CUSTOMER SERVICE.
If you experience a problem or need parts for this product, visit our website http://www.buffalotools.com
or call our customer help line at 1-888-287-6981, Monday-Friday, 8 AM - 4 PM Central Time. A copy of the
sales receipt is required.
FOR CONSUMER USE ONLY – NOT FOR PROFESSIONAL USE.
KEEP THIS MANUAL, SALES RECEIPT & APPLICABLE WARRANTY FOR FUTURE
REFERENCE.

3901726 JobSmart 4 Gallon Air Compressor Assembly & Operating Instructions 2
TABLE OF CONTENTS
RECOGNIZE SAFETY SYMBOLS, WORDS AND LABELS................................................................2
SERVICE..............................................................................................................................................6
PACKAGE CONTENTS........................................................................................................................6
COMPONENTS....................................................................................................................................6
ASSEMBLY ..........................................................................................................................................7
OPERATION.........................................................................................................................................8
MAINTENANCE..................................................................................................................................10
PARTS LIST.......................................................................................................................................11
PARTS DIAGRAM..............................................................................................................................11
RECOGNIZE SAFETY SYMBOLS, WORDS AND LABELS
What You Need to Know About Safety Instructions
Warning and Important Safety Instructions appearing in this manual are not meant to cover all possible
conditions and situations that may occur. Common sense, caution and care must be exercised when
assembling or using this product.
Always contact your dealer, distributor, service agent or manufacturer about problems or conditions you
do not understand.
This is a 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.
This is a 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.

3901726 JobSmart 4 Gallon Air Compressor Assembly & Operating Instructions 3
GENERAL PRODUCT SPECIFICATIONS
FEATURES:
• Required Oil For Lubrication
• Includes air Regulator & Quick Coupler
• Lightweight Design With Easy-To-Read Gauges
• Pancake Tank Design With Water Drain Valve & Rubber Feet
SPECIFICATIONS
• 5 CFM @ 90 PSI
• 13.8 AMP
• 2 HP MOTOR
• 120V / 60 Hz
• 115 PSI
• Requires SAE 5W-30 motor oil
KEEP THIS MANUAL, SALES RECEIPT & APPLICABLE WARRANTY FOR FUTURE
REFERENCE.
READ ALL INSTRUCTIONS AND WARNINGS BEFORE USING THIS PRODUCT.
When unpacking, check to make sure all parts listed are included. If any parts are missing or broken,
please call Customer Service at 1-888-287-6981.
FOR CONSUMER USE ONLY – NOT FOR PROFESSIONAL USE

3901726 JobSmart 4 Gallon Air Compressor Assembly & Operating Instructions 4
IMPORTANT SAFETY RULES
COMMON SENSE AND CAUTION ARE FACTORS WHICH CANNOT BE BUILT INTO ANY PRODUCT.
THESE FACTORS MUST BE SUPPLIED BY THE OPERATOR.
Keep your work area clean and well lit. Cluttered work benches and dark work areas may cause
accidents or injury.
Keep bystanders, children and visitors away while operating the compressor.Distractions can
cause you to lose control.
Do not force tool. Use the correct tool for your application. The correct tool will do the job better and
safer at the rate for which it is designed.
Store idle tools out of reach of children and other untrained persons. Tools are dangerous in the
hands of untrained users.
Use common sense while operating this compressor.
Do not use this tool if you are:
• Feeling tired or are under the influence of alcohol or drugs.
• Wearing loose clothing or jewelry. Keep long hair pulled back and away from moving parts.
• Overreaching or have improper footing. Handling the tool in this way could cause serious injury.
• Wear the proper safety equipment, such as safety goggles, dust masks, non-skid shoes, etc.
• Check to be sure all adjusting keys or wrenches have been removed before use.
Safety glasses and ear protection must be worn during operation.
Read the manual carefully. Learn the tool's applications and limitations, as well as specific potential hazards
peculiar to it.
Ground all tools. If the tool is equipped with three-pin plug, it should be plugged into a three-pin electrical
socket. Never remove the ground pin.
Avoid body contact with grounded surfaces such as pipes, radiators, ranges, and refrigerators. There is an
increased risk of electric shock if your body is grounded.
Do not expose tool to moisture. Don't use this tool in damp or wet locations: Keep out of rain.
Do not abuse cord. Never use the cord to carry tools or pull the plug from an outlet. Keep cord away from
heat, sharp edges or moving parts. Replace damaged cords immediately. Damaged cords increase the risk
of electric shock.
Remove adjusting keys or wrenches before turning the tool on. A wrench or key that is left attached to a
moving part of the tool may result in personal injury.
Don't overreach. Keep proper footing and balance at all times when operating this tool.

3901726 JobSmart 4 Gallon Air Compressor Assembly & Operating Instructions 5
Disconnect the tool from power source before making any adjustments, storing, servicing, or
changing accessories. This will reduce the risk of starting the tool accidentally.
Do not force tool. Use the correct tool for your application. The correct tool will do the job better and
safer at the rate for which it was designed.
Do not use the tool if the switch does not turn it on and off. Any tool that cannot be controlled with the
switch is dangerous and must be repaired.
Check for damage. Check your tool regularly. If part of the tool is damaged it should be carefully inspected
to make sure that it can perform its' intended function correctly. If in doubt, the part should be repaired.
Refer all servicing to a qualified technician. Consult your dealer for advice.
Keep away from flammables. Do not attempt to operate this tool near flammable materials or
combustibles. Failure to comply may cause serious injury or death.
Store idle tools out of the reach of children and untrained persons. Tools may be dangerous in the
hands of untrained users.
Maintain tools with care. Keep tools sharp and clean. Properly maintained tools, with sharp cutting edges,
are less likely to bind and are easier to control.
Never exceed the pressure rating of any component in system.
Protect material and air lines from damage or puncture. Keep hose and power cable away from
sharp objects, moisture, chemicals, oil, etc.
Check condition of hoses before each use. Do not use a damaged hose. If hose is damaged, replace
immediately.
Read, understand and comply with all warning labels on unit.
Drain tank of moisture after each use. If Compressor is not to be used for extended periods of time, leave
tank drain valve open to allow moisture to completely drain from tank.
Do not tamper with Safety Valve. The Safety Valve is factory set for your model air compressor. Any user
adjustments to Safety Valve will automatically void warranty.
Air compressors get hot while in operation. NEVER touch the motor, discharge tubing or compressor
pump while in operation.
The Compressor operates automatically while the motor is turned on.
Compressed air from the unit may contain carbon monoxide. Air produced is not suitable for breathing purposes.
Always use a respirator when spraying paint or chemicals.
The air pressure switch is set at the factory for optimum performance of your equipment. Never
attempt to bypass or remove this switch as serious damage to equipment or personal injury could result
from excessive air pressure.

3901726 JobSmart 4 Gallon Air Compressor Assembly & Operating Instructions 6
SERVICE
Tool service must be performed only by qualified repair personnel. Service or maintenance by unqualified
personnel could result in a risk of injury.
When servicing a tool, use only identical replacement parts and follow instructions in the manual. Use
of unauthorized parts or failure to follow Maintenance Instructions may create a risk of shock or injury.
SAVE THESE INSTRUCTIONS FOR FUTURE REFERENCE.
This manual contains important information regarding safety, operation, maintenance and storage of this product.
Before use, read carefully and understand all warnings, cautions, instructions and labels. Failure to do so could result
in serious personal injury, property damage or even death.
IMPORTANT SAFETY INSTRUCTIONS
Before using this tool, you need to become familiar with its operation. If you are unsure about the
operation of the tool, or have any questions about its proper use, call the Customer Service Department at
1-888-287-6981. Follow these instructions for safe handling of the tool:
• Be sure your work area is clean and secure. Be sure the area is free from all foreign material, nails,
staples, or any other material.
• Always use the appropriate safety gear when operating. Including but not limited to, goggles, dust
mask or respirator.
PACKAGE CONTENTS
• Air Compressor
• Air Filter
• Air Chuck
• Oil Breather Cap
COMPONENTS
1. Air Filter
2. Handle
3. Air Regulator
4. Air Chuck
5. Pressure Gauges
6. Tank Drain Valve
(Under Compressor)
7. Air Tank
8. Safety Valve
9. Power Switch
10. Oil Breather Cap
4
1
10
8 5
9
7 6
3
2

3901726 JobSmart 4 Gallon Air Compressor Assembly & Operating Instructions 7
Handle: Rubber gripped handle for easy transport.
Air Regulator: Controls the air flow pressure. Turn regulator
clockwise to increase air pressure, counter-clockwise to
decrease.
Air Chuck: Allows for fast, easy connection to an air hose.
Tank Drain Valve: Open to allow moisture and compressed
air to be released from the Air Tank.
WARNING The Tank Drain Valve should always be
opened slowlv to avoid damage to equipment and
possible injury.
Oil Breather Cap: As the compressor motor operates
pressurized air must be released from the crank case. The oil
breather cap allows built up air to escape, while shielding your
air compressor from airborne impurities.
Air Tank: Powder coated steel tank, with a 4 gallon capacity,
stores the compressed air until it is needed.
Power Switch: Red tipped power switch turns the air
compressor on and off. When switch is pulled up, compressor
is turned ON. When switch is pushed down, compressor is
turned OFF.
Note: Always make sure that compressor Power Switch is in
the OFF position before performing any maintenance or
plugging the compressor Into a power supply.
Pressure Gauges: Dual gauges indicate the amount of air
pressure built up in the air tank, as well as the air pressure
being delivered to the air chuck.
Safety Valve: Relieves pressure from the Air Tank in the
event of excessive pressure build up. Preset at factory. Do not
attempt to make any adjustments to the Safety Valve.
Periodically pull ring on the Safety Valve end to check that it is
working properly.
Air Filter: Heavy duty metal air filter keeps your compressor
running clean by filtering out impurities.
ASSEMBLY
Before performing any assembly or maintenance, make sure compressor is turned off and unplugged
from the power supply.
Your air compressor is shipped without oil in the crankcase. YOU MUST ADD OIL TO THE CRANKCASE
BEFORE STARTING THE AIR COMPRESSOR.
1. Place compressor on level ground.
2. Remove the Oil Shipping Plug from the Oil Fill hole, located on the top of the crankcase cover at the rear.
3. Pour the oil into the Oil Fill hole, until the oil level rises to the center of the red dot on the Oil Sight Glass.
Note: This compressor uses only SAE 5W-30 motor oil.
4. Install the Oil Breather Cap into the Oil Fill hole.
5. Firmly hand-tighten the Oil Breather Cap by turning clockwise.
lnstalling the Air Chuck
Note: Use a sealant tape on the threads of the Air Chuck to prevent air leakage.
1. Thread the Air Chuck into the Air Regulator by turning the Air Chuck clockwise.
2. Securely tighten the Air Chuck in place with a wrench.
Note: DO NOT over tighten Air Chuck.
lnstalling the Air Filter
The metal Air Filter is installed into the threaded port of the cylinder head.
1. Thread the Air Filter into the Cylinder Head by turning Air Filter clockwise.
2. Securely tighten the Air Filter in place with a wrench. (See Figure 4)
Note: DO NOT over tighten Air Filter.
Figure 4
lnstalling the
Air Filter
Figure 3
lnstalling the
Air Chuck
Figure 2
lnstalling the
Oil & Oil
Breather Cap
Oil Fill
Crankcase
Sight Glass
Drain Plug

3901726 JobSmart 4 Gallon Air Compressor Assembly & Operating Instructions 8
OPERATION
BEFORE OPERATING YOUR NEW AIR COMPRESSOR please read manual
carefully.
1 Check that all nuts and bolts are secure.
2. Make sure oil has been properly added to compressor.
Initial Start-up Procedure
1. Open the Air Tank Drain Valve to permit air to escape, preventing air pressure buildup in the air tank.
2. Run the compressor for a minimum of 20 minutes in this "no-load" position to lubricate the piston and bearings.
3. Close Air Tank Drain Valve. Your compressor is ready for use.
Depending on the CFM draw of the tools being operated, your new Air Compressor can be used for operating
paint sprayers, air tools, grease guns, airbrushes, caulking guns, abrasive blasters, tire & plastic toy inflation,
spraying weed killer and insecticides, etc. Proper adjustment of the Air Pressure Regulator is necessary for all of
these operations. Refer to the air pressure specifications provided with the tool you are using.
General Overview
To compress air, the piston moves up and down in the cylinder. On the down stroke air is drawn in through the
valve inlet. The discharge valve remains closed. On the upstroke of the piston air is compressed. The inlet valve
closes and air is forced out through the discharge valve, through the check valve, and into the air tank. Working
air is not available until the compressor has raised the tank pressure above that required at the air service
connection. The air inlet filter openings must be kept clear of obstructions, which could reduce air delivery of the
compressor.
Installation and Location
Locate the compressor in a clean, dry and well ventilated area. The compressor should be located 12 to 18
inches from walls or any other obstruction, which would interfere with airflow. Compressor should be located in a
temperature controlled area between 32" and 95" fahrenheit. Place the compressor on a firm, level surface. The
compressor is designed with heat dissipation fins which allow for proper cooling. Keep the fins (and
911 other parts which collect dust or dirt) clean. A clean compressor runs cooler and provides longer service. Do
not place rags, containers or other material on top of the compressor.
Connecting to Power Source
This air compressor is designed to operate on a properly grounded 120 volt, 60Hz, single phase, alternating
current (AC) power source with a fused 20 amp time delayed fuse or circuit breaker. It is recommended that a
qualified electrician verify the ACTUAL VOLTAGE at the receptacle into which the unit will be plugged and
confirm that the receptacle is properly fused and grounded. The use of the proper circuit size can eliminate
nuisance circuit breaker tripping while operating your air compressor.
Extension Cords
For optimum Air Compressor performance an extension cord should not be used unless
absolutely necessary. If necessary, care must be taken in selecting an extension cord appropriate for use with
your specific Air Compressor. Select aproperly grounded extension cord which will mate directly with the power
source receptacle and the Air Compressor power cord without the use of adapters. Make certain that the
extension cord is properly wired and in good electrical condition. Maximum length of extension cord should be 50
feet. Minimum wire size of extension cord should be 12 gauge.

3901726 JobSmart 4 Gallon Air Compressor Assembly & Operating Instructions 9
Attaching an Air Hose
Your Air Compressor is supplied with a 114"'Quick Disconnect Air Chuck. Once you have correctly installed the
Air Chuck your compressor will be ready to accept air hoses equipped with 114" male air couplers. (Figure 5)
Note: Use only air hoses rated for use with 115 PSI air pressure or higher.
To install an air hose, equipped with a 114" male coupler:
1. Pull back on Air Chuck outer sleeve to allow coupler to be fully inserted into Air Chuck.
2. Insert coupler into Air Chuck.
3. Release outer sleeve of Air Chuck.
4. Verify that air hose is securely connected to Air Chuck by pulling on air hose.
Adjusting the Air Pressure
Your Air Compressor is supplied with an Air Pressure Regulator. This Regulator adjusts the air pressure.
To increase air pressure, turn Air Regulator clockwise.
To decrease air pressure, turn Air Regulator counterclockwise. (Figure 6)
Cold Weather Starting
Temperatures below freezing (32°F) cause the metal parts of your Air Compressor to contract and that makes
starting more difficult. To assist the Air Compressor in starting in cold weather, follow these tips:
1. Try to keep Air Compressor stored in temperatures above 32 °F.
2. Open the Air Tank Drain Valve and release all air pressure from the Air Tank before attempting to start in cold
weather. (After air is released from Air Tank, close Drain Valve.)
3. Plug Air Compressor directly into a 120 volt electrical outlet. Do not use an extension cord when starting your
Air Compressor in cold weather.
Figure 5
Figure 6

3901726 JobSmart 4 Gallon Air Compressor Assembly & Operating Instructions 10
MAINTENANCE
Daily (or before each use)
1. Check oil level
2. Drain condensation from the air tank.
3. Check for any unusual noise or vibration.
4. Be sure all nuts and bolts are tight.
Weekly
1. Clean breather hole on Oil Breather Cap.
Monthly
1. Inspect air system for leaks by applying soapy water to all joints. Tighten these joints if leaks are discovered.
6 Months (or after 250 hours of operation - whichever comes first)
1. Change Air Compressor Oil. Note: Change oil more often if Air Compressor is used near paint spraying
operations or in dusty environments.
Checking the Air Compressor Oil
1. Place Air Compressor on level surface. The oil level should be at the red dot on the Oil Sight Glass.
2. If oil level is low, remove Oil Breather Cap and add enough oil to bring the oil level to the red
dot on the Oil Sight Glass.
3. Replace Oil Breather Cap before starting compressor.
Changing the Air Compressor Oil
Note: This compressor uses only SAE 5W-30 motor oil.
1. Remove the Drain Plug under the Oil Sight Glass by turning the nut counterclockwise with wrench.
Note: Oil will begin to drain as Drain Plug is loosened. Place a funnel and oil pan in place BEFORE loosening
Drain Plug.
2. Once Drain Plug is removed, tilt Air Compressor backwards to allow all of the oil to drain out of
the crankcase.
3. Once oil is drained, replace Drain Plug and securely tighten in place with a wrench. Be careful not to
overtighten the Drain Plug, as this could damage the rubber seal.
4. Place Air Compressor on level surface.
5. Remove the Oil Breather Cap.
6. Slowly pour the oil into the oil fill hole, until the oil level rises to the center of the red dot on the Oil Sight Glass.
7. Install the Oil Breather Cap into the oil fill hole.
8. Firmly hand tighten the Oil Breather Cap by turning clockwise.
Always inspect the tool before use, and make sure it is in good working condition. Make sure all air
vents are clear, (use compressed air to clean the machine where possible). Check the power cable to
make sure it is intact and free from cracks, bare wires etc. Avoid using solvents when cleaning plastic parts.
Most plastics are susceptible to damage from the various types of commercial solvents.

3901726 JobSmart 4 Gallon Air Compressor Assembly & Operating Instructions 11
PARTS DIAGRAM
PARTS LIST
Part # Description QTY
AC410001 Plastic Housing AC410025 Oil Breather Cap AC410049 Check Valve
AC410002 Spring Washer AC410026 Spring Washer 8 AC410050 Unload Pipe
AC410003 Washer AC410027 Washer 8 AC410051 Air Tank
AC410004 Screw M5x14 AC410028 Screw M8x20 AC410052 Tank Drain Valve
AC410005 Fan AC410029 Connecting Rod AC410053 Rubber Feet
AC410006 Screw M5x115 AC410030 Piston AC410054
Screw M6x20/nut M6
AC410007 Rear Cap , AC410031 Spring Washer 12 AC410055 Power Cord
AC410008 Washer AC410032 Piston Pin AC410056 Rubber Gasket
AC410009 Bearing 6202 AC410033 Cylinder Gasket AC410057 Centrifugal Switch
AC410010 Stator AC410034 Cylinder AC410058 Seal Washer
AC410011 Rotor AC410035 Spring Washer 6 AC410059 Nut
AC410012 Starting Capacitor AC410036 Washer 6 AC410060 Connector Seat
AC410013 Running Capacitor AC410037 Screw M6x40 AC410061 Rubber Grip
AC410014 Bearing 6204 AC410038 Gasket AC410062 Safety Valve
AC410015 Oil Seal AC410039 Sealer Ring AC410063 Pressure Gauge
AC410016 Nut M8 AC410040 Valve Gasket AC410064 Pressure Switch
AC410017 Crankcase AC410041 Valve Plate Assy AC410065 Connector
AC410018 Crankshaft AC410042 Air Intake Valve AC410066 Pressure Gauge
AC410019 Screw M8x16 (left) AC410043 Limit Pin AC410067 Regulator
AC410020 Gasket AC410044 Cylinder gasket AC410068 Air Chuck
AC410021 Crankcase Cover AC410045 Metal Air Filter
AC410022 Oil Sight Glass AC410046 Cylinder Head
AC410023 Drain Plug AC410047 Elbow Exhaust
AC410024 Pan Head Screw AC410048 Exhaust Pipe

12
Troubleshooting
If Compressor won’t start
1. Blown Fuse or circuit breaker tripped-Replace or reset fuse/circuit breaker
2. Loose electrical connections-Check wiring connections
Low Pressure
1. Restricted air flow-Replace Air Filter
2. Defective check valve-Replace check valve
3. Air Leak in safety valve-Check valve by pulling on ring. If condition persists, replace valve.
Safety valve releasing
1. Defective pressure switch-Replace pressure Switch
Oil Discharge in air
1. Too much oil in crankcase-Drain crankcase and refill to proper level on oil sight glass.
2. Compressor overheated-Reduce air pressure regulation
3. Restricted oil breather cap-Clean or replace oil breather cap
(3901726201005)