Polair Systems portable air compressor User manual

ROLAIR SYSTEMS
606 S. Lake Street, P.O. Box 346
Hustisford Wisconsin 53034-0346
Phone: [phone]
Sales Fax: [phone]
Service Fax: [phone]
www.rolair.com
PORTABLE
AIR COMPRESSOR
OWNER’S MANUAL
WARNING
COMPRESSOR DISCHARGE AIR MAY CONTAIN HYDROCARBONS AND
OTHER CONTAMINANTS! DO NOT USE DISCHARGE AIR FOR BREATHING!
PARTS
Genuine ROLAIR replacement parts are sold nationwide through a network of authorized dealers and
service centers. Please contact the dealership where your air compressor was purchased or our factory
Customer Service Department if you need help troubleshooting, obtaining parts, or locating an
authorized ROLAIR service representative.
To order replacement parts: 1. Give compressor model number
2. Give compressor serial number
3. Name of part
4. Part number
5.
Q
uantit
y
re
q
uired

TABLE OF CONTENTS
Introduction and Definitions of Safety Warnings--------------------------------------------------------- 1
Safety Warnings – Risk of Asphyxiation & Bursting---------------------------------------------------- 2
Safety Warnings – Risk of Electrocution, Shock, Explosion, & Fire-------------------------------- 3
Safety Warnings – Risk of Moving Parts, Burns, & Lifting--------------------------------------------- 4
Safety Warnings – Risk of Propelled Objects, Unsafe Operation, and Damage---------------- 5
To Compressor or Property
Identification of System Controls---------------------------------------------------------------------------- 6-7
Pre-Start Checklist---------------------------------------------------------------------------------------------- 8
Operation---------------------------------------------------------------------------------------------------------- 9
Maintenance------------------------------------------------------------------------------------------------------ 10-11
Troubleshooting-------------------------------------------------------------------------------------------------- 12
Guarantee--------------------------------------------------------------------------------------------------------- 13
RECORD OF PERTINENT INFORMATION
Make a permanent record of the model and serial number of your new air compressor
here. You’ll save time and expense by including this reference information when requesting
service or replacement parts.
Place & Date of Purchase Volts
Model HZ
Serial # HP
With the tank gauge at 0 PSI and air line(s) disconnected, close drain valve(s) and record
the amount of time it takes to build tank pressure on the space provided. Periodically test your air
compressor against this pump-up time to determine if it is operating correctly. If time test is
considerably off, contact your local ROLAIR representative to arrange service.
From 0 to ______*PSI From 0 to ______*PSI
Date Min Sec Date Min Sec
*Record the top end pressure setting of your air compressor in the space provided and
perform pump-up time test several times each year or if a pumping problem is suspected.

INTRODUCTION
Congratulations on the purchase of your new ROLAIR air compressor!
With over 45 years experience building ROLAIR air compressors specifically designed for the
professional, Associate Engineering Corporation has earned a reputation for providing a product
unsurpassed in quality and reliability. We are committed to continuing this tradition by analyzing
and adapting to the changing needs and rigorous demands of your industry. You can depend on
ROLAIR because they are built to last.
This manual was compiled for the benefit of the operator. Do not use or allow anyone else to use
your air compressor until this manual is read and all safety/operating instructions are understood.
By reading and following the instructions contained in this manual, you can acheive years of
trouble free service from your new air compressor. If you have any additional safety or operating
questions after reading this manual, please contact your distributor or our customer service
department. Do not remove or paint over any of the warning decals attached to the compressor.
Definitions – Safety Warnings
Safety symbols are used throughout this manual to alert you to potentially hazardous situations.
The following definitions describe the level of severity for each signal word.
DANGER: Indicates an imminently hazardous situation which, if not avoided,
WILL result in death or serious injury.
WARNING: Indicates a potentially hazardous situation which, if not avoided,
COULD result in death or serious injury.
CAUTION: Indicates a potentially hazardous situation which, if not avoided,
MAY result in minor or moderate injury or damage to the air compressor.
WARNING
The engine exhaust from this product
contains chemicals known to the State
of California to cause cancer, birth
defects or other reproductive harm.

SAFETY WARNINGS
Read and Understand all Safety Warnings before using Air Compressor
Hazard Level
Risk of Asphyxiation
Risk of Bursting
Potential of Hazard
Serious injury or death may occur
from inhaling compressed air. The
air stream may contain carbon
monoxide, toxic vapors, or solid
articles.
p
Sprayed materials such as paint,
stucco, insecticides, solvents, etc.
contain harmful vapors and poisons
that may cause serious injury or
eath if inhaled.
d
Serious injury or death may occur if
the exhaust from gas-powered
small engines is inhaled. Engine
exhaust fumes contain poisonous,
carbon monoxide which is odorless
nd colorless.
a
Serious injury or death may occur
from an air tank explosion if the air
tanks are not properly maintained
or if modifications, alterations, or
repairs are attempted to the air
eceivers.
r
Serious injury or death may occur if
modifications are made to the pilot
unloader valve, pressure switch,
safety relief valve, or other
components that control the tank
ressure.
p
Serious injury may occur if
accessories or attachments are
operated above the manufacturer’s
recommended pressure ratings,
causing them to explode or fly
apart.
How to Avoid Hazard
Never inhale compressed air directly from
the pump, receiver, or from a breathing
evice connected to the air compressor.
d
Operate compressor only in a well-
ventilated area. Use a respirator device
and follow the manufacturer’s
recommendations for their spray
equipment. Keep compressor at least 25
eet away from spray equipment.
f
Operate gas-powered compressors only in
a well-ventilated area. Avoid inhaling
engine exhaust fumes, and never run a
small gas-powered engine in a closed
building or confined area without adequate
entilation.
v
Drain air tanks daily or after each use.
Never drill into, weld, patch, or modify the
air tanks. If a leak develops replace the
tank immediately, or replace the entire
ompressor.
c
Never make adjustments to the
components that control tank pressure. Do
not make alterations to the factory
operating pressure settings. Check
operation of the safety valve on a regular
basis and never operate without a factory
pproved safety valve.
a
Do not use air tools or attachments before
reading the owner’s manual to determine
the maximum pressure recommendations.
Never exceed the manufacturer’s maximum
allowable pressure ratings. Do not use
compressor to inflate small low pressure
objects such as toys.

SAFETY WARNINGS
Read and Understand all Safety Warnings before using Air Compressor
Hazard Level
Risk of Electrocution or
Electrical Shock
Risk Explosion or Fire
Potential of Hazard
Serious injury or death could occur
if the air compressor is not
properly grounded.
Electrical shock may occur if
compressor is not properly
operated.
Serious injury or death may occur
if electrical repairs are attempted
by unqualified personnel.
Serious injury or death may result
from normal electrical sparks that
occur within the motor and/or
pressure switch.
Serious injury may occur if a fire is
caused by overheating due to
inadequate ventilation or
restrictions to any of the
compressors ventilation openings.
Serious injury or death may occur
from a fire or explosion if spilled
gas or vapors come in contact with
hot engine parts and ignite.
How to Avoid Hazard
Always plug compressor into a
properly grounded outlet which
provides correct voltage, proper
grounding, and adequate fuse
rotection.
p
Never operate air compressor in wet
conditions or outdoors when it’s
raining. Disconnect power and bleed
tank pressure before servicing.
Do not operate with damaged power
cord or with protective electrical
overs removed.
c
Do not allow electric cords to lay in
water. Do not touch plug with wet
hands. Do not pull on electric cord to
isconnect from the outlet.
d
Any electrical repairs or wiring
performed on this compressor should
only be performed by authorized
service personnel in accordance with
the National and Local Electric Codes.
Always operate compressor in a well-
ventilated area free of combustible
materials, gasoline, flammable
olvents, or vapors.
s
Always locate compressor at least 20
feet away from work area if spraying
flammable materials.
Never place objects against or on top
of an air compressor. Always operate
air compressor at least 18” away from
any wall or obstruction. Always
operate in a clean, dry, and well-
ventilated area.
Never attempt to fill the gas tank while
the engine is hot or running. Add fuel
outdoors in a well-ventilated area. Do
not fill gas tank near lit cigarettes or
near other sources of ignition.

SAFETY WARNINGS
Read and Understand all Safety Warnings before using Air Compressor
Hazard Level
Risk From
Moving Parts
Risk of Burn
Risk of Injury
from Lifting
Potential of Hazard
Serious injury may occur from
moving parts such as belts,
pulleys, flywheels, or fans if they
came in contact with you or your
clothing.
An electric air compressor with
automatic controls can restart at
any time and cause bodily injury
when least expected.
Serious injury may occur if repairs
are attempted with damaged,
missing, or removed protective
guards, shrouds or missing covers.
Serious burn injuries could occur
from touching exposed metal parts
such as the compressor head,
copper/braided discharge lines,
and engine exhaust muffler during
operation, and even after
compressor is shut down for
sometime.
Serious injury can result from
attempting to lift an object that is
too heavy.
How to Avoid Hazard
Never operate the air compressor
without protective belt guards
installed. Replace damaged
protective covers or guards
mmediately.
i
Always unplug air compressor and
drain air tanks completely before
attempting any repairs or performing
maintenance. Never allow children or
adolescents to operate air
compressor.
All repairs to the air compressor
should be made only by authorized or
rained service personnel.
t
Never touch any of the exposed metal
parts during operation and for an
extended period of time after the air
compressor has shut down.
Do not attempt maintenance on the
unit until it has been allowed to
completely cool.
Always obtain assistance from others
before attempting to lift any object that
is too heavy for one person.

SAFETY WARNINGS
Read and Understand all Safety Warnings before using Air Compressor
Hazard Level
Flying objects
Warning
Risk of Unsafe
Operation
Caution
Risk of Damage
to Air
Compressor or
Property
Potential of Hazard
Serious injury may occur from
loose debris being propelled at
high speeds from the compressed
air stream.
Serious injury or death may occur
to you or others if air compressor
is used in an unsafe manner.
Failure to transport or operate the
air compressor properly may result
in major repair expenses.
Oil leaks will damage carpets,
painted surfaces, flooring, and
other items.
How to Avoid Hazard
Always wear OSHA required “287” safety
glasses to protect the eyes during
operation of the air compressor. Never
point the air stream or tools at any point
of your body, other people, or animals.
Always turn off the air compressor and
drain tank pressure completely before
attempting maintenance, or attaching air
tools.
Review and understand all instructions
and warnings in your owner’s manual.
Know how to stop the air compressor. Do
not operate until you are thoroughly
familiar with all of the controls. Do not
operate the compressor if fatigued or
under the influence of alcohol or drugs.
Stay alert while operating the
compressor, and pay close attention to
he task at hand.
t
Check oil levels daily and maintain proper
oil levels. Always run compressor in a
level, secure position, that keeps it from
tipping or falling during use. Do not
operate without an air filter or in a
corrosive environment.
Always transport in a level position and
use protective mats to keep truck beds
clean, etc. Check drain bolts regularly
and do not overfill machinery with oil.
Please note that this product may not be equipped with a spark arresting muffler. If the compressor is operated
around flammable materials or agricultural crops, brush, forests, and grasslands an approved spark arrestor must be
installed, maintained, and in good working order. An approved spark arrestor is legally required in the State of
California under sections 4442 and 4443 of the California Public Resources Code Statute section /30050.
This product contains chemicals, including lead, known to the state of California to cause cancer, birth defects, and
other reproductive harm. Always wash hands after handling this product.

SYSTEM CONTROLS
(1) SAFETY RELIEF VALVE Every ROLAIR air compressor is equipped with a safety relief valve which is designed to
discharge tank pressure at a predetermined setting when a systems failure occurs. Check the safety valve periodically by
pulling on the ring only when the tank pressure is completely drained. The spring loaded valve should move freely within the
safety valve body. An inoperable safety valve could allow an excessive amount of tank pressure to build causing the air tank to
catastrophically rupture or explode.
Do not tamper with or attempt to eliminate the safety relief valve.
(2) MANUALOVERLOAD/MOTORRESET Every ROLAIR electric air compressor is built with manual overload protection. If
the motor overheats, the overload sensor will trip the reset button to protect the motor. If this occurs, please allow the motor to
cool for approximately five minutes. Locate and push in the reset button. The use of an undersized or excessive length of
extension cord may be the cause of overheating. Re-evaluate the power source and gauge/length of extension cord being
used. (Refer to chart on page 8)
(3) PRESSURE SWITCH Most electric air compressors are operated by the use of a pressure switch. Always make sure
the lever is in the off position before plugging in the power cord. By moving the lever to the “On/Auto” position, the compressor
will start and stop automatically within the settings of the pressure switch which are typically 105 – 130 PSI. Do not attempt to
stop the compressor by unplugging the power cord. To stop, simply move the lever to the “Off” position. The lever operates a
relief valve that dumps off head pressure and allows the compressor to restart without load the next time it is used.
(4)REGULATOR–WORKING PRESSURE To adjust the output/line pressure, simply lift up on the regulator adjustment knob
and rotate clockwise to increase working pressure or counter-clockwise to decrease. Push adjustment knob back down to lock
in setting. Never exceed the manufacturer’s maximum allowable pressure rating of the tool being used or item being inflated.
(5) PRESSURE GAUGE(S) Typically, most compressors are designed with a gauge to measure tank or storage pressure
and another gauge attached to the regulator that indicates output or working pressure.
(6) DRAIN VALVE(S) One or more drain valves are installed to allow moisture to be drained on a daily basis from the
compressor storage tank(s). Open drains carefully and slowly to prevent scale, rust, or debris from becoming expelled at a
high rate of speed.
(7) AIR INTAKE FILTER Air intake filters are installed to prevent foreign matter from entering into the engine or
compressor pump. Check intake elements on a regular basis and either clean or replace as needed. Warm soapy water or
low compressed air may be used to clean the elements. Check intake canisters or elbow components for cracks or broken
seals and replace if structural problems are found.

(8) PILOT UNLOADER VALVE A pilot unloader valve is used on all gas-powered units and can be used on electric air
compressors to operate in a continuous manner. When the storage tank reaches the top pressure setting of the pilot valve,
the air being compressed is discharged to atmosphere instead of into the storage tank. When the tank pressure drops to the
low pressure setting of the pilot valve, the compressed air will be redirected to the air tank. Do not attempt to replace the pilot
valve without first draining the tank pressure completely. See Figure 3 for adjustment and fine-tuning instructions. Do not
adjust above the following factory recommendations.
Classification Pressure Setting
Direct Drive Compressor 105-130 PSI
I-Stage Compressor 110-135 PSI
II-Stage Compressor 130-150 PSI
(9) SIGHT GAUGE/DIPSTICK Prior to daily operation, make a habit of checking the oil level of the compressor pump and
engine (if compressor is gas-powered). Every direct drive hand-carry air compressor has a dipstick to help check and maintain
the proper oil level. The dipstick also functions as a crankcase vent. Never operate a direct drive unit without the factory
supplied dipstick. Our belt-driven air compressors are equipped with a sight gauge to make the daily task of checking the oil
level easier. Always maintain the oil level to read 2/3 full on the sight gauge.
(10) CHECK VALVE Every ROLAIR air compressor is built with a check valve to seal off and maintain tank pressure after
the top end pressure setting of pilot valve or pressure switch is reached. The check valve works in conjunction with the
pressure switch relief valve to provide a loadless start for the compressor system. A quick burst of air escaping from the
pressure switch relief valve after an electric unit reaches top end indicates the check valve is working properly. If the
compressor has a mysterious leak after stopping that cannot be traced elsewhere, the check valve may require
servicing/replacing.
(11) BREATHER/OIL FILL PLUG All reciprocating air compressor pumps are built with a crankcase vent to relieve the
pressure that is created by the downward movement of the piston in the pump cylinder. Our direct drive air compressors vent
the crankcase pressure through special ports in the dipstick. Our belt-driven units vent through the oil fill plug. Never operate
the air compressor without the dipstick or oil fill plug.
(12) AUTOMATIC IDLE CONTROL Every ROLAIR gas-powered air compressor is built with an engine idle control kit
that automatically decreases the engine speed when the top end pressure setting of the pilot unloader valve is reached. The
top RPM setting of the engine is factory set for maximum performance and service life. Do not alter the factory top RPM
setting. The engine idle speed is factory set and controlled by a black plastic Philips head screw on the carburetor. A slight
increase to the idle speed setting may be required when operating in colder temperatures. Turn screw clockwise in ¼ turn
increments to increase the idle speed. If the idle speed setting is too low, premature fouling of spark plug will occur.
(13) COLD-START VALVE Most ROLAIR direct drive air compressors are built with an automatic cold-start valve that
allows the motor/pump to warm up before being subjected to tank pressure. Our belt-driven portable units have a manual drain
valve installed on the pump aftercooler to assist with cold weather starting. Open drain valve and allow the motor and pump to
run unloaded for a minute to warm up. Close the drain and repeat the procedure if the motor or engine continue to struggle.
(14) SCHMIDT BELT TIGHTENING DEVICE (FOR GAS UNITS ONLY) Every ROLAIR gas-powered belt-driven
portable air compressor has a unique system for maintaining proper belt tension. Simply loosen the ½” locknuts (only until
washers beneath spin freely) that secure the engine and rotate the fine thread bolt located on the wheel end of the base plate
clockwise until the desired belt tension is achieved. (See drawing in section on operating instructions for proper tension) Re-
tighten ½” locknuts to secure engine and maintain desired belt tension setting.
(15) VIBRATION DAMPENER(S) The rubber pads installed beneath every portable ROLAIR tank assembly are very
important to the proper operation of the air compressor. They provide protection from vibration that left unchecked could cause
damage to many system components.
(16) ENGINE KILL SWITCH A kill switch is installed to easily stop the engine. Do not attempt to move the throttle lever
(as described in the Honda owner’s manual) when stopping the engine. The engine throttle lever is factory set and locked
down at a top RPM setting that will provide maximum performance and service life for the complete air compressor system.
The kill switch must be moved to the “On” position prior to pulling the recoil rope assembly to start the engine.
(17) ENGINE CHOKE Moving the choke lever completely to the left (closed position) will help start a cold engine. Also see
instructions for cold-start valve (Item # 13). After start up, the choke lever must be moved completely to the right (open
position) for the engine to operate properly. Fouling of spark plug and excessive internal carbon build up will occur if engine is
operated with choke lever even partially closed.
(18) FUEL SHUT-OFF VALVE The fuel shut off valve should only be moved to the “Open” position (completely to the
right) when the engine is being operated. Always stop the flow of fuel by moving the shut-off valve completely to the left when
the engine is not being operated. Do not move or transport the air compressor with the fuel valve in the open position.

PRE-START CHECKLIST
Read the owner’s manual thoroughly. Make sure that you completely understand all of
the safety warnings, system controls, and instructions provided before attempting to operate this
air compressor. Every effort has been made to provide you with the information needed to obtain
many years of reliable and trouble-free service out of your new air compressor. It is your
responsibility to operate the air compressor properly. To obtain the longest possible service life
from your air compressor you must always keep the following instructions in mind.
1. ALWAYS OPERATE THE COMPRESSOR IN A LEVEL POSITION
All splash lubricated pumps have a dipper on the bottom of the connecting rod that must
remain submerged in the oil bath. Operation at more than a 10 degree angle will cause the
pump to seize and void the product warranty
2. OPERATE IN A CLEAN, DRY, AND WELL VENTILATED AREA
Allow at least 18” behind the belt guard for proper cooling of pump from flywheel blast. Do not
operate in the rain or in areas of standing water. Never operate in an area where other gases,
fumes, or vapors are present which may become explosive when compressed. Do not
operate compressor in an enclosed area.
3. CHECK OIL LEVEL DAILY AND CHANGE AT REGULAR INTERVALS
Refer to the maintenance section of this owner’s manual for the correct type/weight of oil to
use and how often the oil should be changed. Check oil levels daily.
4. INSPECT/CLEAN/CHANGE INTAKE ELEMENTS ON A REGULAR BASIS
The ingestion of dirt into the pump and engine is the primary cause of premature wear. Pay
special attention to the intake filters. Check intake filters daily.
5. USE LONGER PROPERLY SIZED AIR HOSE RATHER THAN EXTENSION CORDS
If an extension cord must be used, please refer to the chart below for the proper gauge and
maximum length that can be used. The use of inadequately sized air hose will also lead to
frictional pressure drops that could affect the proper performance of your air tools.
6. DO NOT USE A GENERATOR AS THE POWER SOURCE
Air compressors use inductive motors that require 3-5 times the full load amp draw to
properly start. Most generators will not provide the wattage needed to properly start this type
of electric motor.
7. CHECK TENSION OF BOLTS, BELTS, AND HARDWARE ON A REGULAR BASIS
Operation of any equipment with loose bolts and/or fittings will lead to excessive vibration and
the premature failure of the compressor system control components.
8. MAINTAIN RUBBER VIBRATION PADS
Excessive vibration is a major cause of premature compressor failure. Always maintain the
rubber vibration pads located beneath tank assembly. Operation without them will void your
warranty.
9. DRAIN MOISTURE FROM AIR TANKS DAILY
Water is a natural byproduct of compressed air. Drain air tank(s) after each use to combat
internal tank corrosion. Keep drain valve(s) closed if storing compressor for any length of
time.
ELECTRIC EXTENSION CORD TABLE
Minimum Wire Size
Extension
Cord Length Motor ½ and ¾ HP Motor 1, 1 ½, and 2 HP
Up to 25 ft. 14 Ga. 12 Ga.
25 – 50 ft. 12 Ga. 10 Ga.
50 – 100 ft. 10 Ga. 8 Ga.

OPERATION
WARNING – Your safety and the wellbeing of others during the operation of every ROLAIR
compressor is our main concern. Do not operate or permit anyone else to operate your air
compressor until the information contained in this manual is read and completely understood.
Please contact your distributor or our customer service department if you have any questions on
the proper use of your air compressor.
DIRECT DRIVE ELECTRIC
Establish that the air compressor is ready to operate by reviewing the topics and information
provided in the “Pre-Start Checklist” section of this manual. Slowly open tank drain to remove any
condensate that has accumulated and keep drain open for a few seconds after starting to warm
up motor/pump assembly. Make sure the pressure switch lever is in the “Off” position before
plugging power cord into a properly grounded outlet. Move pressure switch lever to the “On/Auto”
position to build and automatically maintain top end tank pressure setting. Rotate regulator
adjustment knob counterclockwise until the gauge attached reads 0 PSI before attaching air hose
and accessory. Set working pressure by rotating regulator adjustment knob clockwise and lock in
working pressure according to specifications provided by the tool manufacturer. Always use the
pressure switch “On(Auto)/Off” lever to start or stop the air compressor. Never stop the
compressor by unplugging it from the power source. Store compressor in a warm/dry location &
perform maintenance as indicated in manual.
BELT-DRIVEN ELECTRIC
Follow same procedures described for use of direct drive
electric compressor. Use the drain valve located on the
pump aftercooler for cold-starting purposes. Your belt-
driven electric compressor may be set up for dual control
operation. See figure 1 for instructions to switch operation
from start/stop to constant speed. Use constant speed
operation during periods of heavy use to extend motor life
and prevent overheating. An electric belt-driven motor
should not be subjected to more than fifteen starts per
hour. Consult your dealer or any authorized ROLAIR
service center for information on a conversion kit if you
experience nuisance tripping of the motor overload due to
an excessive amount of start/stops.
GAS-POWERED
Refer to item numbers 12, 16, 17, & 18 in the “System Controls” section of this manual for
information on the engine automatic idle control, kill switch, choke, and fuel shut off valve.
Additional instructions can be found in the engine owner’s manual. Use the drain valve located on
the pump aftercooler or intercooler for cold-starting purposes. Take additional care to keep
dirt/debris from entering the fuel tank or obstructing the air flow through the engine or past the
pump. Make sure the air flow to the regulator is completely closed (gauge attached reads 0 PSI)
before attaching air hose and accessory. A slight hissing noise caused by the air flow being
directed to atmosphere during engine idle is normal. Store compressor in a warm/dry location and
perform maintenance as indicated in your manuals.

MAINTENANCE
Your new air compressor represents the finest engineering and construction available. Even the best
machinery requires periodic maintenance. Please stick to the maintenance schedule and consider the
suggestions that follow to keep your compressor in peak condition.
NOTE: Always unplug or shut down your compressor and drain the air tanks completely before
attempting any type of maintenance. Wait for compressor to cool before servicing.
IMPORTANT: Replace the oil after the first 50 hours of operation.
MAINTENANCE HINTS: 1) Use a soap/water solution to check for air leaks.
2) Never clean filters with a flammable solvent.
3) Retorque head bolts only after pump has cooled.
4) Move motor 1/4" and roll belts back on to increase
belt tension on electric units.
5) Never weld on air tank(s).
6) Use heat to loosen loctite seal on drain valves, engine
pulleys, and flywheels before attempting to remove.
LUBRICATION
Prior to each use, make a habit of checking the pump oil
level. Most direct drive air compressors have a dipstick with casting
marks that indicate the minimum and maximum acceptable levels of
oil. Our belt-driven pumps have a sight gauge, located on the
outside of the crankcase, to make the task even easier. Always
maintain the oil level at the maximum mark on the dipstick or to 2/3
full in the sight gauge
Do not operate the pump with an inadequate or excessive
amount of oil. The cost of failures which occur due to incorrect oil
levels will not be covered under warranty.
DO NOT USE A DETERGENT OIL!
NOTE: Unit must be level when in operation
OIL TYPE TABLE
Temperature 0-40° 40° & Above
NON-DETERGENT – Straight Weight 10WT* 30WT*
*For maximum performance and service life, we recommend using ROLAIR Premium Quality compressor oil.
MAINTENANCE SCHEDULE
Recommendation Daily Weekly Monthly Quarterly
Check Oil Level X
Drain Moisture from Tank(s) X
Inspect Air Filter(s) X
Check for Unusual Noise or Vibration X
Inspect Belt Guard X
Check for Air or Oil Leaks X
Clean Exterior of Air Compressor X
Check Condition of Vibration Pads X
Tighten/Retorque Bolts X
Check Belt Tension X
Check Operation of Safety Valve X
Change Compressor Oil X
Clean/Change Air Filter X
Perform Pump Up Time Test X
Check Operation of System Controls X
Check Air Tanks for Dents/Leaks X

TORQUE CHART (INCH/LBS)
Pump Type Direct Drive K12 K17 K18 K24 K28 K30
Head Bolts 96 243 243 243 243 391 391
Cylinder Bolts 120 182 182 182 182 330 330
Bearing Carrier Bolts N/A 130 130 130 130 130 130
Connecting Rod Bolts N/A 121.5 121.5 121.5 121.5 121.5 121.5
Flywheel N/A 243 382 382 382 477 477
Determine pump type using suffix of Model number (Example: 4090HK17 uses K17 pump)
PILOT VALVE ADJUSTMENT
RESETTING DIFFERENTIAL (2)
Make sure the top toggle lever is positioned as shown. (See Figure 3). Loosen
locknut (1) by turning counterclockwise several full turns. Gently turn differential
setting (2) clockwise only until the internal rod makes contact with the steel ball
inside. After making contact, turn differential (2) counterclockwise ¼ turn. Secure
position by tightening locknut (1) and proceed to top end setting.
TOP END SETTING (4)
Loosen locknut (3) by turning counterclockwise several full turns. (4) is the top end
setting. Turning (4) clockwise will increase the top end pressure setting. Turning
counterclockwise will decrease the top end pressure setting. Begin at a low setting
by turning counterclockwise one full turn. Proceed to fine tuning instructions.
FINE TUNING INSTRUCTIONS
Start engine/motor and observe tank pressure gauge. As tank pressure approaches
100-130 P.S.I.G., the pilot valve should begin unloading at felt muffler and cause
gas engine to slow down to idle speed. If pilot valve does not unload as tank
pressure approaches 130 P.S.I.G., slowly turn top end setting (4) counterclockwise
until pilot starts to unload prematurely (at 100 P.S.I.G.), turn top end setting (4)
clockwise in ¼ turn increments, tap down on the internal rod at toggle attachment
and repeat until desired top end setting is reached. If pilot valve begins to rifle
(sputter), fine tune differential setting (2) 1/16 turn in either direction until rifling
stops. After fine tuning, secure setting by turning locknuts (1 & 3) clockwise until
tight. Hold setting (2 & 4) in place while turning locknuts to secure.
DRIVE PULLEYS
SCHMIDT BELT TIGHTENING DEVICE
(FOR GAS UNITS ONLY)
To tighten belt tension, proceed as follows:
1. Loosen locknuts for engine hold-down bolts only until washers
beneath spin freely.
2. Rotate ½” adjusting bolt clockwise until desired tension is
reached. (See Figure 4).
3. Retighten locknuts to secure engine.
Drive pulleys must be properly aligned and
drive belt tension set to specification. Improper
pulley alignment and belt tension can cause
motor overloading, excessive vibration, and
premature belt and/or bearing failure.
(See Figure 5).
GASOLINE ENGINE RPM SETTINGS
Model Top RPM Idle RPM Pump RPM
4090 Series 2950 1900 1025
1040 & 2040 Series 2775 1900 1175
6590 Series 3150 1900 1125
8422 & 8230 Series 3000 1900 900
NOTE: Engine RPM’s (High – Low Settings) are factory set for maximum efficiency. Adjusting RPM’s
above factory specification will void the warranty.

TROUBLESHOOTING
WARNING - Make sure you completely understand all of the safety warnings and
operation of each system control component before attempting any maintenance or repair.
Always drain the tank pressure completely, make sure the power cord is unplugged, and unit has
time to cool before performing any maintenance or service operations.
PROBLEM CAUSE SOLUTION
Loose/slipping belt Adjust belt tension
Excessive leaks in system Correct air leaks
Blown gasket Replace head gaskets
Broken reed valve Replace reed valves
Obstructed intake filter Clean or replace intake
element
Leaking regulator Replace regulator
Pump is slow to build tank
pressure
Defective pilot valve Replace pilot valve
Too much oil in crankcase Drain to proper level
Improper weight of oil Replace with proper oil
Obstructed crankcase vent Replace dipstick or oil fill
plug/crankcase vent
Dirty/plugged intake filter Clean/replace intake filter
Worn piston rings Take unit in for service
Excessive oil consumption
Scored cylinder Take unit in for service
Loose pulley or flywheel Tighten appropriate parts
Loose belts Adjust belt tension
Knocking noise Internal pump problem Take unit in for service
Poor ventilation Relocate compressor
Improper pump rotation Rewire for correct rotation
Overheating compressor Internal pump problem Take unit in for service
Thermal overload tripped Locate and push reset button
Reset physically broken Replace overload/reset
Loose motor leads or electrical
connection Locate and correct loose electrical connection(s)
Electric motor dead,
will not even hum
Short in power cord Replace power cord
Motor is starting/stopping
excessively Install constant speed or dual control kit
Overload is defective/weak Replace overload
Improper gauge of extension
cord Use longer lengths of air hose or heavier cord
Stripped or poorly tightened
motor thru bolts Retighten or replace stripped thru bolts
Motor trips overload/reset
button
Cracks in end bell or housing Take unit in for service
Fouled, incorrect, or
improperly gapped spark plug Install proper spark plug after gapping to factory specs
Improper engine oil level Fill to top of threads for oil plug
Improper weight of pump or
engine oil Change to proper weight of oil for operating temperature
Gasoline engine is hard to
start
Improper or old gas Take unit in for service

Guarantee
Associate Engineering Corporation warrants that all ROLAIR compressors will be free of defects in
material and workmanship for a period of twelve months from the date of initial retail purchase, or
eighteen months from the date of manufacture, whichever may occur first.
Should any failure to conform to this warranty be reported to the company within said period, the
company shall, upon purchaser shipping the compressor to our plant transportation prepaid, correct
such nonconformity by suitable repair or, at its option, furnish a replacement part F.O.B. our plant.
Associate Engineering Corporation shall not be liable for any unauthorized repairs, replacements,
adjustments to the compressors, or the costs of labor performed by the purchaser.
This warranty is expressly in lieu of all other warranties expressed, implied or statutory (including, but
not limited to, warranties of merchantability and fitness for purpose) and of any other obligations,
and/or liabilities on the part of Associate Engineering Corporation. Associate Engineering Corporation
neither assumes nor authorizes any other person to assume for it any other obligations or liability in
connection with or with respect to any compressor.
Associate Engineering Corporation shall in no event be liable neither for any consequential, incidental
or special damages nor for the improper selection of any compressor for a particular application.
Quality
Associate Engineering Corporation is devoted to continual quality control and thorough
research of the products we build. It is our creed to give you, the user, all of the
experience and engineering available in the production of every piece of equipment we
produce.
Our line covers the complete needs of today’s varied air requirements. Rely on ROLAIR for
all the newest and finest features that are available for the modern compressor.
ROLAIR SYSTEMS
606 South Lake Street, P O Box 346
Hustisford Wisconsin 53034-0346
Phone: [phone]
Sales Fax: [phone]
Service Fax: [phone]
www.rolair.com
PBN0017 11/07