NorthStar M4592900A.4 User manual

1
M4592900A.4
Owner’s Manual
Belt-Driven Air Compressor Pumps
Instructions for Installation/Set-up, Operation, Maintenance, & Storage
This NorthStar® belt-driven compressor pump has either a single stage 2-cylinder pump (Model 4592900),
2-stage 3-cylinder pump (Model 4593000) or a 2-stage 2-cylinder pump (Model 4593100), made with heavy-duty cast
iron cylinders for long life, and a compact design rated for 130 maximum PSI (4592900) or 175 maximum PSI
(4593000 and 4593100). Its continuous-duty rating ensures long-lasting performance, and its cast iron pump head
ensures superior heat dissipation.
Read and understand this Owner’s Manual completely before using. Keep this manual for future review. Failure to
properly set up, operate and maintain the compressor pump in accordance with this manual could result in serious
injury or death to operator or bystanders.
WARNING: SPECIAL HAZARDS
Injection Injury: High-pressure air stream can pierce skin and underlying tissues, leading to serious injury and possible
amputation. Such an injection injury can result in blood poisoning and/or severe tissue damage.
Flying Debris: High-pressure air stream can cause flying debris and possible surface damage.
Not For Breathing Air: NorthStar compressor pumps are NOT designed, intended, or approved for supplying breathing air.
No compressed air should be used for breathing unless air is treated in accordance with applicable standards.
Fire/Explosion: Sparks from air powered tool heads or attachments can ignite fuel or other flammable liquids or vapors in
the vicinity. Exceeding the maximum pressure for air tools or attachments could cause them to explode.
Burns: Compressor pump, motor and discharge tubing are hot surfaces that can cause burn injuries.
Detailed safety information about these hazards appears throughout this manual.
Equipment Protection Quick Facts
Inspect Upon Delivery: FIRST! Inspect for missing or damaged components. See “Initial Set-Up”section for where
to report missing or damaged parts.
Check Pump Oil: Pump is NOT shipped with oil. Check the pump oil level before starting. See “Preparing for
Operation”section of this Owner’s Manual for capacity and viscosity.
Install a Regulator: We recommend installing a regulator on the compressor at each distribution point to maintain
constant pressure in the outlet hose line and provide reduced pressure appropriate for air tool being used.
Run Pump Unloaded for Break-in Period: Before initial use, open drain valves and run compressor pump for 30
minutes to break in pump parts.
Follow Maintenance Schedule: Pump, air filter, and tank require periodic inspection and servicing to provide
efficient function and long life. See “Maintenance Schedule”for frequency of servicing.
ITEM NUMBER: 4592900, 4593000,
4593100
SERIAL NUMBER: _____________

2
Table of Contents
Equipment Protection Quick Facts ........................................................................................................................................ 1
Table of Contents ........................................................................................................................................................2
About Your Air Compressor Pump ............................................................................................................................4
Specifications ..............................................................................................................................................................5
Engine / Motor Pulley Sizing Calculations............................................................................................................................. 5
Component Identification ...........................................................................................................................................6
Mounting Dimensions .................................................................................................................................................7
Safety Signal Words....................................................................................................................................................8
Hazard Signal Word Definitions ............................................................................................................................................ 8
Initial Set-Up ................................................................................................................................................................9
Step 1. Inspect & Unpack........................................................................................................................................................ 9
Step 2. Assembly..................................................................................................................................................................... 9
Attach Regulator (Recommended)........................................................................................................................................ 9
Step 3. Select Suitable Location............................................................................................................................................. 9
Operation ...................................................................................................................................................................10
Follow Operation Safety Rules............................................................................................................................................. 10
Prepare for Operation............................................................................................................................................................ 10
Check/Add Oil to the Pump................................................................................................................................................. 10
Proper Air Hose and Tool Use.............................................................................................................................................. 11
Pressure Control Related Devices...................................................................................................................................... 11
Compressor - Tool Requirements ....................................................................................................................................... 11
Using Compressor Pump for Spraying................................................................................................................................ 11
Flammable Materials........................................................................................................................................................... 11
Moisture in Compressed Air................................................................................................................................................ 11
For Malfunction During Operation....................................................................................................................................... 12
Maintenance & Repair...............................................................................................................................................13
Maintenance Schedule Summary.............................................................................................................................13
Detailed Instructions –Maintenance & Repair........................................................................................................13
Inspect Safety/Relief Valve ................................................................................................................................................. 13
Inspect Air Filter .................................................................................................................................................................. 13
Keep Compressor Clean..................................................................................................................................................... 13
Inspect Compressor for Air Leaks....................................................................................................................................... 14
Change Pump Oil................................................................................................................................................................ 14
Check Drive Belt for Tension and Alignment....................................................................................................................... 14
Keep Compressor Clean..................................................................................................................................................... 14
Troubleshooting ........................................................................................................................................................15
4592900 Pump Explosion .........................................................................................................................................16
4592900 Pump Parts List ..........................................................................................................................................17
4592900 Pump Kits....................................................................................................................................................17
4593000 Pump Explosion .........................................................................................................................................18
4593000 Pump Parts List ..........................................................................................................................................19
4593000 Pump Kits....................................................................................................................................................20

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4593100 Pump Explosion .........................................................................................................................................21
4593100 Pump Parts List ..........................................................................................................................................22
4593100 Pump Kits....................................................................................................................................................23
Appendix A: Lubricants and Compatibility .............................................................................................................24
Alternate Lubricants. ........................................................................................................................................................... 24
Limited Warranty .......................................................................................................................................................25

4
About Your Air Compressor Pump
Thank you for purchasing a NorthStar air compressor
pump! It is designed for long life, dependability, and top
performance.
Intended Use. Provides compressed air used primarily
for operating air tools and pressurizing other objects
that require high air pressure, such as tires.Do not
use for low-pressure objects such as balloons, air
mattresses, and sport balls, which can explode
quickly and easily. Special precautions are
necessary when used for cleaning to prevent flying
debris hazards. It is not to be used to supply
breathing air.
Supplies Required. Normal operation will require you
to supply:
Pressure regulator (recommended)
Pump oil
Personal protection equipment
See “Specifications”section for more detail.
Site Location. Intended for indoor/outdoor use.
Personal Protection. Wear safety apparel during
operation, including safety glasses with side and top
protection.
Adult Control Only. Only trained adults should set up
and operate the air compressor pump. Do not let
children operate.
Under The Influence. Never operate, or let anyone else
operate, the air compressor pump while fatigued or
under the influence of alcohol, drugs, or medication.
Keep this manual for reference and review.
ATTENTION: Rental Companies and Private
Owners who loan this equipment to others!
All persons to whom you rent/loan this air compressor
pump must have access to and read this Owner’s
Manual. Keep this manual with the air compressor pump
at all times and advise all persons who will operate the
machine to read it. You must also provide personal
instruction on how to safely set-up and operate the air
compressor pump and remain available to answer any
questions a renter/borrower might have. Owner’s
Manuals are available from NorthStar at 1-800-270-0810.

5
Specifications
MODEL
Model #
4592900
4593000
4593100
Stages
1-stage
2-stage
2-stage
Cylinders
2-cylinder
3-cylinder
2-cylinder
Outlet Port Size
5/8”
1/2”
3/4”
FLOW OUTPUT
Max. Pressure Rating
130 PSI
175 PSI
175 PSI
Volume Rating @ 90PSI
13.7 CFM
14.9 CFM
17.4 CFM or 24.4 CFM
Pump Flywheel Diameter
10.5”
12.5”
16”
Maximum Pump RPM
1396 RPM
1242 RPM
809 RPM or 1132 RPM
MOTOR / ENGINE HORSEPOWER REQUIREMENT
Electric Motor
4 HP min.
5 HP min.
5 HP min. or 7.5 HP min.
Gasoline Engine
5.5 HP min.
9 HP min.
9 HP min. or 13 HP min.
DIMENSIONS / COMPONENTS
Length
14.9”
19.7”
22.8”
Width
12.6”
13.7”
13.8”
Height
12.6”
16.9”
20.5”
Weight
52 lbs.
73 lbs.
123 lbs.
Belt Style
A groove –Qty 1
A groove –Qty 1
A groove –Qty 2
SUPPLIES REQUIRED (not included)
Pump Oil
(shipped with oil, but
refills required)
SAE 30 non-detergent
pump oil (#4043)
SAE 30 non-detergent
pump oil (#4043)
SAE 30 non-detergent
pump oil (#4043)
Pump Oil Capacity
15.6 oz.
27 oz.
33.8 oz.
Engine / Motor Pulley Sizing Calculations
Engine/Motor Pulley Diameter = Pump RPM x Pump Flywheel Diameter
Engine/Motor RPM
Pump RPM = Engine/Motor Pulley Diameter x Engine/Motor RPM
Pump Flywheel Diameter

6
Component Identification
1. Oil Cap: A cover for the hole where the oil is poured in.
2. Breather Cap: Allows air to enter/exit the crankcase.
3. Air Filter: Removes particles from the air before they
reach the pump. Keep clean and particle free. See
“Pump Explosion and Pump Parts List” for replacement
part number.
4. Sight Glass: A window through which the level of oil can
be checked visually.
5. Magnetic Oil Drain Plug: Removal allows for drainage
of oil from pump. Attracts metal particles that could
damage pump.
6. Intercooler: Cools the compressed air as it travels
between stages. The flywheel/fan creates an air flow that
rushes past and cools the intercooler.
7. Aftercooler: Cools the compressed air from the pump
before it enters the receiver tank. The heat from the
compressed air is transferred outward to the cast iron
fins of the Aftercooler, the flywheel/fan creates an air
flow that rushes past and cools the cast iron fins.
Oil Cap
Sight
Glass
Magnetic Drain
Plug
Breather Cap
Air Filter
Oil Cap
Sight
Glass
Magnetic Drain
Plug
Breather Cap
Air Filter
Oil Cap
Sight
Glass
Magnetic Drain
Plug
Breather
Cap
Air Filter
Intercooler
Intercooler
Aftercooler
Aftercooler
Intercooler
4592900
4593000
4593100

7
Mounting Dimensions
4592900
4593000
4593100
0

8
Safety Signal Words
Hazard Signal Word Definitions
DANGER
WARNING
CAUTION
CAUTION
NOTICE
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 (red) indicates a hazardous situation, which if
not avoided, will result in death or serious injury.
WARNING (orange) indicates a hazardous situation,
which if not avoided, could result in death or serious
injury.
CAUTION (yellow), used with the safety alert symbol,
indicates a hazardous situation, which if not avoided,
could result in minor or moderate injury.
CAUTION (yellow), without the safety alert symbol, is
used to address practices not related to personal injury.
NOTICE is used to address practices not related to
personal injury.

9
Initial Set-Up
Step 1. Inspect & Unpack
Upon receipt, inspect air compressor pump for missing
or damaged parts. Verify that it is the compressor pump
you ordered.
See “Component Identification” section of this manual
for a diagram of the compressor pump and its
components.
For missing components, contact Product
Support at 1-800-270-0810.
For damaged components, contact the freight
company that delivered the unit and file a claim.
If complete, fill out product serial number
information. See “Limited Warranty” section of
this manual.
Step 2. Assembly
Attach Regulator (Recommended)
We recommend using a regulator with these
compressor pumps since most pre-set tank pressure
ranges are between 145 and 175 PSI and that is usually
greater than what is needed by tools.
Without the addition of a regulator, the pressure switch
or unloader will maintain a tank pressure within the pre-
set range that may have a max of 130 or 175 PSI. This
is considered an overly high pressure for many tools. A
user-installed regulator can maintain a lower constant
pressure in the outlet hose line and prevent over
pressurization of tools.
WARNING: Bursting hazard
Too much air pressure causes a hazardous risk of
bursting. Check the manufacturer’s maximum pressure
rating for air tools and accessories. Regulators must
never be set to exceed the maximum pressure rating of
tank or tools.
Step 3. Select Suitable Location
Location Criteria:
Where no flammable vapors, dusts, and gases
are present.
At least 15” away from walls and other objects.
Away from other heat-generating equipment.
Away from dusty/dirty conditions.
In a well illuminated area.
Airflow:
Provide access to adequate, clean and
unobstructed airflow for cooling and air supply.
Do not allow debris to accumulate or block
airflow.
Do not operate with a tarp, blanket, or cover
surrounding the machine, which blocks air flow..
Ideal operating temperatures:
40and 100F (4and 37C).
Operating Limitations:
15F (-9C) or above 125F (52C).
If temperatures consistently drop below 32F (0C),
install within a heated building. If this is not possible,
protect the safety/relief and drain valves from freezing.
Note: Excessive moisture is likely to occur if unit is
stored in an unheated area subject to large
temperature changes. Moisture forming in pump can
produce sludge in the oil, causing parts to wear out
prematurely. Excessive condensation on the pump
when it cools down is a sign that this may be
occurring.

10
Operation
Follow Operation Safety Rules
Before starting the compressor pump, review the safety
rules found below and throughout the manual.
WARNING
Failure to follow safety rules may result in serious injury
or death to the operator or bystanders.
Instruct Operators. Owner must instruct all operators in
safe set-up and operation. Do not allow anyone to
operate the compressor pump who has not read the
Owner’s Manual.
Safety Guarding. Only operate with safety covers,
guards and barriers secured and in good working
order.
Moving Parts. Keep hands, feet, hair and apparel away
from moving parts. Never remove any guards while
the unit is operating. Do not reach into an air vent or
cavity, as they may cover dangerous moving parts.
Ear Protection. Hearing can be damaged from
prolonged, close-range exposure to the noise level
produced by this compressor. Ear plugs or other
hearing protection is recommended for persons
working who are exposed within 15-20 feet of the
running compressor for an extended period of time.
Eye Protection. Wear ANSI/OSHA required “Z87.1”
safety glasses when operating or servicing the
compressor. Pressurized air spray from this unit can
cause severe injury to the eyes. Also, small objects
will become airborne as the air spray contacts them.
Respirator. Wear a respirator when using the
compressed air for spraying. Spray in a well-
ventilated area to prevent health and fire hazards.
Prepare for Operation
Make sure that any regular maintenance has been
performed as prescribed in “Maintenance & Repair”
section.
Drain receiver tank of any moisture.
Inspect for oil leaks.
Check for any unusual noise/vibration.
Ensure the area around compressor pump is free
from rags, tools, debris and flammable or
explosive materials.
Ensure belt guards and covers are securely in
place.
WARNING: Entanglement hazard
Do NOT operate with protective covers or guards
removed. Beneath these covers are high speed moving
components, which can entangle the operator or
bystanders. Entanglement in this equipment may result
in serious injury, amputation or death.
Check/Add Oil to the Pump
Check the oil level in the pump. Use sight glass for
pump oil level. Add oil as needed.
WARNING: Burn hazard
Never open oil port while compressor pump is running.
Hot oil can spray over face and body.
CAUTION: Inadequate lubrication hazard
Never operate compressor pump with inadequate
lubricant. This will cause overheating and severe
damage to the pump.
4592900 Model Pump: The compressor pump capacity
is 15.6 oz. Use SAE 30 non-detergent pump oil (part
#4043) prior to break-in. You may use synthetic
lubricants after 50 hour break-in period. See “Lubricants
and Compatibility”for a list of suitable and alternative
lubricants.
Oil Cap
Sight
Glass
Magnetic Drain
Plug
Breather Cap

11
Figure 8
4593000 Model Pump: The compressor pump capacity
is 27 oz. Use SAE 30 non-detergent pump oil (part
#4043) prior to break-in. You may use synthetic
lubricants after 50 hour break-in period. See “Lubricants
and Compatibility”for a list of suitable and alternative
lubricants.
Figure 9
4593100 Model Pump: The compressor pump capacity
is 33.8 oz. Use SAE 30 non-detergent pump oil (part
#4043) prior to break-in. You may use synthetic
lubricants after 50 hour break-in period. See “Appendix
A: Lubricants and Compatability” for a list of suitable and
alternative lubricants.
CAUTION: Synthetic lubrication damage
If you will be using a synthetic lubricant, all downstream
piping material and system components must be
compatible.
CAUTION: Break-in period
Before initial use, open the drain valves and run the
compressor pump without air tools attached and
through open air line for 30 minutes to break-in pump
parts.
WARNING: Inflatables/Low PSI tire
Never use compressor to inflate small low-pressure
objects, i.e., balloons/inflatables, small or low volume
PSI tires. It is easy to over-pressurize them, causing
them to rupture. Identify the inflation capacity of an
object prior to filling it with air. Use a gauge to check the
pressure regularly when inflating anything.
Proper Air Hose and Tool Use
Pressure Control Related Devices
Never remove, adjust, bypass, change, modify or make
substitutions for safety/relief valves, pressure switches
or other pressure control related devices. Pressurizing
beyond the limits of the compressor could result in an
explosion.
WARNING: Overpressurization hazard
NEVER over-pressurize the receiver tank or air tools
beyond nameplate capacity. Exceeding the pressure
rating could cause them to explode or fly apart.
Compressor - Tool Requirements
Compressor and attachments must be sized properly
for pressure and air volume.
Consider the maximum pressure requirements and
air volume requirements of each. (The volume rating
of your compressor pump is listed in the
“Specifications”section.)
CAUTION: Tool overpressure hazard
Do not operate this unit with any tool rated less than the
maximum operating pressure of the unit (130 PSI or
175 PSI) unless a properly sized regulator limiting
pressure is used before the tool.
Using Compressor Pump for Spraying
Flammable Materials
Always follow precautions on container labels or MSDS’
before spraying flammable materials, such as paint.
Moisture in Compressed Air
Moisture in supply air when compressed will form into
droplets as it leaves air compressor pump and enters
receiver tank. When humidity is high or when a
compressor is in continuous use for an extended period
of time, a significant amount of moisture will collect in
the tank. Part of the moisture will be discharged in the
outlet air.
Oil Cap
Sight
Glass
Magnetic Drain
Plug
Breather Cap
Oil Cap
Sight
Glass
Magnetic Drain
Plug
Breather
Cap

12
When using a paint spray or sandblast gun, this water
will be carried from the tank through the hose, and out of
the gun as droplets mixed with the spray material. If this
is not acceptable for your application, an external air
dryer must be added to the system.
WARNING: Risk of bursting
Drain air receiver tank daily or after each use to prevent
moisture buildup in the air tank. Serious injury or death
may occur from a tank explosion caused by moisture
induced tank corrosion.
For Malfunction During Operation
Immediately turn off the compressor pump if any of the
following conditions arise during operation:
Excessive change in motor speed, slow or fast
Overheating
Excessive vibration
Unusual noise
Flame or smoke
Air leakage
Pull ring on safety valve to immediately relieve pressure.
WARNING: Shutdown hazards
Do not leave an operating machine unattended. Always
shut the machine OFF and relieve the pressure before
leaving the machine. NEVER disconnect the high-
pressure outlet hose from the unit while the tank and air
line are pressurized. A hazardous high pressure air
stream will result as receiver tank is quickly emptied.

13
Maintenance & Repair
WARNING: Maintenance hazards
ALWAYS disconnect, lock out and tag the main power supply and then release air pressure from the receiver tank before
cleaning, adjusting, or servicing the compressor pump. Make sure all guards and shields are replaced before re-starting.
Maintenance Schedule Summary
Item
Frequency
Inspect safety/relief valves
Weekly
Check pump oil level
Weekly
Inspect air filter
Weekly
Replace every 12 months or 1000 hours of
use
Inspect for air leaks
Monthly
Change pump oil/ Clean magnetic drain plug
After first 50 hours of use
Every 3 months or 500 hours of use after
that
Check drive belt tension and alignment
Monthly
Dust/debris removal
Monthly
See detailed instructions for each maintenance item below.
Detailed Instructions –Maintenance & Repair
NOTICE
Dispose of used motor and pump oil in a manner that is
compatible with the environment and in accordance
with local, state, and federal laws and regulations.
Take used oil in a sealed container to your local
recycling center or service station for reclamation.
Do not throw it in the trash, pour it on the ground, or
pour it down a drain.
No Modifications. Never modify or alter the
compressor pump in any way. Modifications can create
serious safety hazards and will void the warranty.
Inspect Safety/Relief Valve
This valve should be inspected and tested on a weekly
basis. The safety valve automatically releases air if the
tank pressure exceeds the preset maximum.
Check the safety/relief valve by pulling the rings.
It is spring loaded and should not be stuck but
come out about ¼” and then snap back into
position when released.
Replace safety/relief valves that do not operate
freely with a valve of the same pressure rating.
WARNING: Safety/Relief valve hazards
If the safety/relief valve does not work properly, over-
pressurization may occur causing air tank rupture or
explosion. Occasionally pull the ring on the safety valve
to make sure the safety valve operates freely. If the
valve is stuck or does not operate smoothly, it must be
replaced with a valve having the same pressure rating.
Inspect Air Filter
Inspect the compressor pump’s air filter on a weekly
basis. A dirty air filter will not allow the air compressor
pump to operate at full capacity.
Clean air filter if dirty and restricted air flow.
Replace the air filter every 12 months or 1000
hours.
Note: Do not operate with the air filter removed.
Keep Compressor Clean
Do not allow air intakes to become blocked. If dust or
debris accumulates in the compressor, clean with a
damp cloth or soft bristle brush.
Note: Do not spray compressor with a garden hose or
pressure washer. Water may enter the compressor
and cause damage to the motor and pump.

14
Inspect Compressor for Air Leaks
Inspect system for air leaks on a monthly basis. To test:
Squirt soapy water around joints during
compressor operation and watch for bubbles.
Developing bubbles indicate a leak is present.
Tighten fittings, if necessary.
Change Pump Oil
WARNING: Burn hazard
Never open oil fill port while compressor is running. Hot
oil can spray over face and body.
Every 3 months or 500 hours, change pump oil while
crankcase is still warm. (See “Appendix A: Lubricants”
for suitable alternatives.)
1. Remove the oil fill and drain plugs. Collect the oil
in a suitable container.
2. Replace the oil drain plug and refill compressor
pump crankcase with clean oil.
3. Replace the oil fill plug.
4. Start the unit and run for several minutes. Shut
down the air compressor and recheck the oil
level. If necessary, add more oil. (Figure 12)
Figure 12
Check Drive Belt for Tension and Alignment
CAUTION: Pulley/sheave hazard
Improper pulley/sheave alignment and belt tension can
result in motor overload, excessive vibration and
premature belt and/or bearing failure. To prevent this
from happening, check the pulley/sheave alignment and
belt tension on a regular basis.
Belts will stretch from normal use. When properly
adjusted, a 5 lb. force applied to the belt between the
motor pulley and the pump will deflect the belt about ½”.
To align and adjust drive belt tension:
1. Remove the belt guard cover.
2. Loosen the four fasteners securing the motor to
the compressor unit.
3. Slide the motor to achieve proper belt tension.
(Usually 1/8”to 1/4” is sufficient.) The belt must
be properly aligned before refastening the motor.
4. To align belt, lay a straight edge against the face
of the compressor sheave (flywheel) touching the
rim at two places. (Figure 13)
Figure 13
5. Adjust the motor pulley by shifting the motor so
that the belt runs parallel to the straight edge.
6. If necessary, use a gear puller to move the motor
pulley. Tighten set screw after motor pulley is
positioned.
7. Check for proper belt tension. (Figure 14)
Figure 14
8. Tighten the four fasteners holding the motor to
the top plate while tension and alignment is
maintained.
9. Attach the belt guard cover.
Keep Compressor Clean
Do not allow air intakes to become blocked. If dust or
debris accumulates in the compressor, clean the
compressor with a damp cloth or soft bristle brush.
Note: Do not spray compressor with a garden hose or
pressure washer. Water may enter the compressor
and cause damage to the engine and pump.
IMPORTANT
If a part needs replacement, only use parts that meet
the manufacturer’s part number specifications.
Replacement parts that do not meet specifications may
result in a safety hazard or poor operation of the
compressor. Major service, including installation or
replacement of parts, should be made by a qualified
electrical service technician.
Full
Add

15
Troubleshooting
This section provides a list of the more frequently encountered compressor pump malfunctions, their causes and
corrective actions. Some corrective actions can be performed by the operator or maintenance personnel, but others
may require assistance of a qualified Service Center.
PROBLEM
POSSIBLE CAUSE
Excessive noise, vibration, knocking or rattling.
B, C, D, F, G, K
Lights flicker or dim when running.
E
Air delivery drops off.
D, E, F, G, H, K, L, M
Compressor pump does not come up to speed.
A, B, D, E
Compressor pump is slow to come up to speed.
A, B, D, E, F
Compressor pump will not unload cycle.
F
Compressor pump will not unload when stopped.
F
Moisture in crankcase, “milky” substance in oil.
I
Oil in discharge air.
J
Safety/relief valve “pops”.
F, G
Low interstage pressure.
M
High interstage pressure.
L
POSSIBLE CAUSE
POSSIBLE SOLUTION
A.) Pump oil viscosity too high for ambient temperature
Drain existing lubricant and refill with proper lubricant.
B.) Belt tension too tight or sheaves not aligned
Check tension/ alignment.
C.) Compressor pump components leaky, broken, loose
Inspect components. Clean or replace as required.
D.) Loose flywheel or motor pulley, excessive end play in
motor shaft or loose drive belts
Check flywheel, motor pulley, crankshaft drive belt
tension/alignment. Replace or repair as required.
E.) Leaking check valve or check valve seat blown out
Replace check valve.
F.) Clogged or dirty inlet and/or discharge line
Clean or replace.
G.) Defective safety/relief valve
Replace.
H.) Inadequate ventilation around flywheel
Relocate compressor pump for better air flow.
I.) Detergent lubricant in crankcase.
Replace with proper lubricant.
J.) Lubricant level too high
Drain excess lubricant.
K.) Worn cylinder finish
Deglaze cylinder with 180 grit flex-hone.
L,) Low pressure inlet valve leaking
Inspect, clean or repair as required.
M.) High pressure inlet valve leaking
Inspect, clean or repair as required.
Any Questions, Comments, Problems or Parts Orders call NorthStar Product Support
at 1-800-270-0810.

16
4592900 Pump Explosion –Rev A.4
Fig04497

17
4592900 Pump Parts List –Rev A.4
4592900 Pump Kits –Rev A.4
Ref#
Part#
Description
Qty
Kit #
1
N/A
Cylinder head
2
Kit # 1
2
N/A
Allen bolt set
8
Kit # 1
3
789354
Air filter *
2
N/A
4
789355
Filter element
2
N/A
5
N/A
Cylinder head gasket
2
Kit # 2
6
N/A
In.& ex. valve assembly
2
Kit # 3
7
N/A
Valve seat gasket
2
Kit # 2
8
N/A
Double head screw set
8
Kit # 4
9
N/A
Cylinder
2
Kit # 5
10
N/A
Cylinder gasket
2
Kit # 2, 5 or 6
11
N/A
Piston ring
2
Kit # 5, 6
12
N/A
Piston
2
Kit # 5
13
N/A
Rod
2
N/A
14
N/A
Crankcase
1
N/A
15
789384
Oil draining plug
1
N/A
16
N/A
Front cover gasket
1
Kit # 2
17
N/A
Front cover
1
N/A
18
N/A
Bolt M6 x 20
4
N/A
Ref#
Part#
Description
Qty
Kit #
19
788880
Oil sight gauge
1
N/A
20
789386
Oil filling plug
1
N/A
21
N/A
Bearing
1
N/A
22
N/A
Crankshaft and balancer
1
N/A
23
N/A
Bearing
1
N/A
24
N/A
Rear bearing seat gasket
1
Kit # 2
25
N/A
Rear bearing seat
1
N/A
26
N/A
Bolt M8 x 20
4
N/A
27
N/A
Oil seal
1
Kit # 2
28
788882
Breathing cover
1
N/A
29
789349
Balanced pulley
1
N/A
30
N/A
Plate washer
1
Kit # 7
31
N/A
Hexagon bolt
1
Kit # 7
32
N/A
Exhaust elbow
1
Kit # 8
33
N/A
Exhaust three way pipe
1
Kit # 8
34
789352
Exhaust tube set
1
N/A
*
789524
Wing nut, air filter
2
N/A
Kit # 5 –Cylinder and Piston Kit–Part # 789342
Ref#
Description
Qty
Kit Qty
9
Cylinder
1
2
10
Cylinder gasket
1
11
Piston ring
1
12
Piston
1
Kit # 6 –Piston Ring Kit–Part # 789359
Ref#
Description
Qty
Kit Qty
10
Cylinder gasket
2
1
11
Piston ring
2
Kit # 7 –Plate and Bolt Kit–Part # 789367
Ref#
Description
Qty
Kit Qty
30
Plate washer
1
1
31
Hexagon bolt
1
Kit # 8 –Elbow and Pipe Kit–Part # 789351
Ref#
Description
Qty
Kit Qty
32
Exhaust elbow
1
1
33
Exhaust three way pipe
1
Kit # 1 - Cylinder Head Kit–Part # 789336
Ref#
Description
Qty
Kit Qty
1
Cylinder head
1
2
2
Allen bolt set
4
Kit # 2 –Gasket Seal Kit–Part # 789339
Ref#
Description
Qty
Kit Qty
5
Cylinder head gasket
2
1
7
Valve seat gasket
2
10
Cylinder gasket
2
16
Front cover gasket
1
24
Rear bearing seat gasket
1
27
Oil seal
1
Kit # 3 –Valve Kit–Part # 789340
Ref#
Description
Qty
Kit Qty
6
In.& ex. valve assembly
2
1
Kit # 4 –Screw Kit–Part # 789358
Ref#
Description
Qty
Kit Qty
8
Double head screw set
4
2

18
4593000 Pump Explosion –Rev A.4

19
4593000 Pump Parts List –Rev A.4
Ref#
Part#
Description
Qty
Kit #
1
N/A
Cylinder head
3
Kit # 1
2
N/A
Allen bolt set
12
3
789354
Air filter *
2
N/A
4
789355
Filter element
2
N/A
5
N/A
Cylinder head gasket
3
Kit # 2
6
N/A
In.& ex. valve assembly
2
Kit # 3
7
N/A
Valve seat gasket
2
Kit # 2
8
N/A
Double head screw set
12
Kit # 4
9
N/A
Cylinder
2
Kit # 5
10
N/A
Cylinder gasket
3
Kit # 2, 5, 6, 9
11
N/A
Piston ring
2
Kit # 5, 6
12
N/A
Piston
2
Kit # 5
13
N/A
Rod
1
N/A
14
N/A
Crankcase
1
N/A
15
789384
Oil draining plug
1
N/A
16
N/A
Front cover gasket
1
Kit # 2
17
N/A
Front cover
1
N/A
18
N/A
Bolt M6 x 20
8
N/A
19
788880
Oil sight gauge
1
N/A
20
789386
Oil filling plug
1
N/A
21
N/A
Bearing
1
N/A
22
N/A
Crankshaft and balancer
1
N/A
23
N/A
Pulley Key
1
N/A
24
N/A
Bearing
1
N/A
25
N/A
Rear bearing seat gasket
1
Kit # 2
26
N/A
Rear bearing seat
1
N/A
27
N/A
Oil seal
1
Kit # 2
28
788882
Breathing cover
1
N/A
29
789366
Balanced pulley
1
N/A
30
N/A
Plate washer
1
Kit # 7
31
N/A
Hexagon bolt
1
32
N/A
Rod
1
N/A
33
N/A
Exhaust elbow
1
Kit # 8
34
N/A
Exhaust three way pipe
1
35
789369
Exhaust tube set
1
N/A
36
789370
Exhaust tube set
1
N/A
37
N/A
In.& ex. valve assembly
1
Kit # 3
38
N/A
Valve seat gasket
1
Kit # 2
39
N/A
Cylinder
1
Kit # 9
40
N/A
Piston ring
1
Kit # 6, 9
41
N/A
Piston
1
Kit # 9
42
N/A
Nipple
1
Kit # 10
43
789396
Pressure relief valve
1
N/A
44
N/A
Plug
1
Kit # 10
45
N/A
Intercooler
1
46
N/A
Exhaust elbow
1
*
789524
Wing nut, air filter
2
N/A

20
4593000 Pump Kits –Rev A.4
Kit # 1 - Cylinder Head Kit–Part # 789336
Ref#
Description
Qty
Kit Qty
1
Cylinder head
1
2
2
Allen bolt set
4
Kit # 2 –Gasket Seal Kit–Part # 789356
Ref#
Description
Qty
Kit Qty
5
Cylinder head gasket
2
1
7
Valve seat gasket
2
10
Cylinder gasket
2
16
Front cover gasket
1
25
Rear bearing seat gasket
1
27
Oil seal
1
38
Valve seat gasket
1
Kit # 3 –Valve Kit–Part # 789357
Ref#
Description
Qty
Kit Qty
6
In.& ex. valve assembly
2
1
37
In.& ex. valve assembly
1
Kit # 4 –Screw Kit–Part # 789358
Ref#
Description
Qty
Kit Qty
8
Double head screw set
4
2
Kit # 5 –Cylinder and Piston Kit–Part # 789342
Ref#
Description
Qty
Kit Qty
9
Cylinder
1
2
10
Cylinder gasket
1
11
Piston ring
1
12
Piston
1
Kit # 6 –Piston Ring Kit–Part # 789360
Ref#
Description
Qty
Kit Qty
10
Cylinder gasket
2
1
11
Piston ring
2
40
Piston ring
1
Kit # 7 –Plate and Bolt Kit–Part # 789367
Ref#
Description
Qty
Kit Qty
30
Plate washer
1
1
31
Hexagon bolt
1
Kit # 8 –Elbow and Pipe Kit–Part # 789368
Ref#
Description
Qty
Kit Qty
33
Exhaust elbow
1
1
34
Exhaust three way pipe
1
Kit # 9 –Cylinder and Piston Kit–Part # 789371
Ref#
Description
Qty
Kit Qty
10
Cylinder gasket
1
1
39
Cylinder
1
40
Piston ring
1
41
Piston
1
Kit # 10 –Intercooler Kit–Part # 789372
Ref#
Description
Qty
Kit Qty
42
Nipple
1
1
44
Plug
1
45
Intercooler
1
46
Exhaust elbow
1