GORMAN-RUPP PUMPS 10 Series User manual

OM-06755-01
March 24, 2015
GORMAN‐RUPP PUMPS
www.grpumps.com
e2015 Gorman‐Rupp Pumps Printed in U.S.A.
INSTALLATION, OPERATION,
AND MAINTENANCE MANUAL
WITH PARTS LIST
10 SERIES PUMP
MODEL
16C20-QSF2.8P FT4

Register your new
Gorman‐Rupp pump online at
www.grpumps.com
Valid serial number and e‐mail address required.
RECORD YOUR PUMP MODEL AND SERIAL NUMBER
Please record your pump model and serial number in the
spaces provided below. Your Gorman‐Rupp distributor
needs this information when you require parts or service.
Pump Model:
Serial Number:
The engine exhaust from this
product contains chemicals
known to the State of California to
cause cancer, birth defects or
other reproductive harm.

TABLE OF CONTENTS
i
INTRODUCTION PAGE I - 1.................................................
SAFETY - SECTION A PAGE A - 1...........................................
INSTALLATION - SECTION B PAGE B - 1....................................
Pump Dimensions PAGE B - 1.....................................................
PREINSTALLATION INSPECTION PAGE B - 1............................................
Battery Specifications And Installation PAGE B - 2....................................
POSITIONING PUMP PAGE B - 2.......................................................
Lifting PAGE B - 2.................................................................
Mounting PAGE B - 2.............................................................
Clearance PAGE B - 3.............................................................
SUCTION AND DISCHARGE PIPING PAGE B - 3.........................................
Materials PAGE B - 3..............................................................
Line Configuration PAGE B - 3......................................................
Connections to Pump PAGE B - 3..................................................
Gauges PAGE B - 3...............................................................
SUCTION LINES PAGE B - 3...........................................................
Fittings PAGE B - 3...............................................................
Strainers PAGE B - 3..............................................................
Sealing PAGE B - 4...............................................................
Suction Lines In Sumps PAGE B - 4.................................................
Suction Line Positioning PAGE B - 4................................................
DISCHARGE LINES PAGE B - 5........................................................
Siphoning PAGE B - 5.............................................................
Valves PAGE B - 5................................................................
Bypass Lines PAGE B - 5..........................................................
AUTOMATIC AIR RELEASE VALVE PAGE B - 6...........................................
Theory of Operation PAGE B - 6....................................................
Air Release Valve Installation PAGE B - 7............................................
ALIGNMENT PAGE B - 8..............................................................
OPERATION - SECTION C PAGE C - 1......................................
PRIMING PAGE C - 1.................................................................
STARTING PAGE C - 1................................................................
OPERATION PAGE C - 1..............................................................
Lines With a Bypass PAGE C - 1....................................................
Lines Without a Bypass PAGE C - 2.................................................
Leakage PAGE C - 2..............................................................
Liquid Temperature And Overheating PAGE C - 2.....................................
Strainer Check PAGE C - 2.........................................................
Pump Vacuum Check PAGE C - 2..................................................
STOPPING PAGE C - 3................................................................
Cold Weather Preservation PAGE C - 3..............................................
BEARING TEMPERATURE CHECK PAGE C - 3..........................................
TROUBLESHOOTING - SECTION D PAGE D - 1..............................

TABLE OF CONTENTS
(continued)
ii
PUMP MAINTENANCE AND REPAIR - SECTION E PAGE E - 1................
PERFORMANCE CURVE PAGE E - 1...................................................
PARTS LISTS:
PUMP MODEL ASSEMBLY PAGE E - 3..............................................
PUMP END ASSY PAGE E - 5......................................................
DRIVE ASSEMBLY PAGE E - 6.....................................................
PUMP AND SEAL DISASSEMBLY AND REASSEMBLY PAGE E - 7.........................
Back Cover Removal PAGE E - 7...................................................
Suction Check Valve Removal PAGE E - 7...........................................
Pump Casing Removal PAGE E - 8.................................................
Impeller Removal PAGE E - 8......................................................
Seal Removal and Disassembly PAGE E - 8..........................................
Separating Intermediate And Drive Assembly From Engine PAGE E - 8..................
Shaft and Bearing Removal and Disassembly PAGE E - 9.............................
Shaft and Bearing Reassembly and Installation PAGE E - 9............................
Securing Intermediate And Drive Assembly To Engine PAGE E - 11......................
Seal Reassembly and Installation PAGE E - 12........................................
Impeller Installation And Adjustment PAGE E - 13......................................
Suction Check Valve Installation PAGE E - 14.........................................
Back Cover Installation PAGE E - 14.................................................
Final Pump Assembly PAGE E - 14..................................................
LUBRICATION PAGE E - 15.............................................................
Seal Assembly PAGE E - 15.........................................................
Bearings PAGE E - 15..............................................................
Engine PAGE E - 15................................................................

10 SERIES OM-06755
PAGE I - 1INTRODUCTION
INTRODUCTION
Thank You for purchasing a Gorman‐Rupp pump.
Read this manual carefully to learn how to safely
install and operate your pump. Failure to do so
could result in personal injury or damage to the
pump.
Because pump installations are seldom identical,
this manual cannot possibly provide detailed in
structions and precautions for every aspect of
each specific application. Therefore, it is the re
sponsibility of the owner/installer of the pump to
ensure that applications not addressed in this
manual are performed only after establishing that
neither operator safety nor pump integrity are com
promised by the installation. Pumps and related
equipment must be installed and operated ac
cording to all national, local and industry stan
dards.
If there are any questions regarding the pump or
its application which are not covered in this man
ual or in other literature accompanying this unit,
please contact your Gorman‐Rupp distributor, or
The Gorman‐Rupp Company:
The Gorman‐Rupp Company
P.O. Box 1217
Mansfield, Ohio 44901-1217
Phone: [phone]
or:
Gorman‐Rupp of Canada Limited
70 Burwell Road
St. Thomas, Ontario N5P 3R7
Phone: [phone]
For information or technical assistance on the
power source, contact the power source manufac
turer's local dealer or representative.
HAZARD AND INSTRUCTION
DEFINITIONS
The following are used to alert maintenance per
sonnel to procedures which require special atten
tion, to those which could damage equipment, and
to those which could be dangerous to personnel:
Immediate hazards which WILL result in
severe personal injury or death. These
instructions describe the procedure re
quired and the injury which will result
from failure to follow the procedure.
Hazards or unsafe practices which
COULD result in severe personal injury
or death. These instructions describe
the procedure required and the injury
which could result from failure to follow
the procedure.
Hazards or unsafe practices which COULD
result in minor personal injury or product
or property damage. These instructions
describe the requirements and the possi
ble damage which could result from failure
to follow the procedure.
NOTE
Instructions to aid in installation, operation, and
maintenance or which clarify a procedure.

10 SERIES OM-06755
PAGE A - 1SAFETY
SAFETY - SECTION A
This information applies to 10 Series en
gine driven pumps. Refer to the manual
accompanying the engine before at
tempting to begin operation.
Because pump installations are seldom
identical, this manual cannot possibly
provide detailed instructions and pre
cautions for each specific application.
Therefore, it is the owner/installer's re
sponsibility to ensure that applications
not addressed in this manual are per
formed only after establishing that nei
ther operator safety nor pump integrity
are compromised by the installation.
Before attempting to open or service the
pump:
1. Familiarize yourself with this man
ual.
2. Switch off the engine ignition and
disconnect the positive battery
cable to ensure that the pump will
remain inoperative.
3. Allow the pump to completely cool
if overheated.
4. Check the temperature before
opening any covers, plates, or
plugs.
5. Close the suction and discharge
valves.
6. Vent the pump slowly and cau
tiously.
7. Drain the pump.
This pump is designed to handle dirty
water containing specified entrained
solids. Do not attempt to pump volatile,
corrosive, or flammable materials, or
any liquids which may damage the
pump or endanger personnel as a result
of pump failure.
Death or serious personal injury and
damage to the pump or components
can occur if proper lifting procedures
are not observed. Make certain that
hoists, chains, slings or cables are in
good working condition and of suffi
cient capacity and that they are posi
tioned so that loads will be balanced
and the pump or components will not be
damaged when lifting. Suction and dis
charge hoses and piping must be re
moved from the pump before lifting. Lift
the pump or component only as high as
necessary and keep personnel away
from suspended objects.
After the pump has been positioned,
make certain that the pump and all pip
ing or hose connections are tight, prop
erly supported and secure before oper
ation.
Do not operate the pump against a
closed discharge valve for long periods
of time. If operated against a closed dis
charge valve, pump components will
deteriorate, and the liquid could come
to a boil, build pressure, and cause the
pump casing to rupture or explode.
Do not remove plates, covers, gauges,

10 SERIES
OM-06755
PAGE A - 2 SAFETY
pipe plugs, or fittings from an over
heated pump. Vapor pressure within the
pump can cause parts being disen
gaged to be ejected with great force. Al
low the pump to cool before servicing.
Do not operate an internal combustion
engine in an explosive atmosphere.
When operating internal combustion
engines in an enclosed area, make cer
tain that exhaust fumes are piped to the
outside. These fumes contain carbon
monoxide, a deadly gas that is color
less, tasteless, and odorless.
Fuel used by internal combustion en
gines presents an extreme explosion
and fire hazard. Make certain that all
fuel lines are securely connected and
free of leaks. Never refuel a hot or run
ning engine. Avoid overfilling the fuel
tank. Always use the correct type of fuel.
Never tamper with the governor to gain
more power. The governor establishes
safe operating limits that should not be
exceeded. Refer to the performance
curve on page E-1 for the maximum
continuous operating speed for this
pump.

OM-0675510 SERIES
PAGE B - 1INSTALLATION
INSTALLATION - SECTION B
Review all SAFETY information in Section A.
Since pump installations are seldom identical, this
section offers only general recommendations and
practices required to inspect, position, and ar
range the pump and piping.
Most of the information pertains to a standard
static lift application where the pump is positioned
above the free level of liquid to be pumped.
If installed in a flooded suction application where
the liquid is supplied to the pump under pressure,
some of the information such as mounting, line
configuration, and priming must be tailored to the
specific application. Since the pressure supplied
to the pump is critical to performance and safety,
be sure to limit the incoming pressure to 50% of
the maximum permissible operating pressure as
shown on the pump performance curve (see Sec
tion E, Page 1).
For further assistance, contact your Gorman‐Rupp
distributor or the Gorman‐Rupp Company.
Pump Dimensions
See Figure 1 for the approximate physical dimen
sions of this pump.
OUTLINE DRAWING
Figure 1. Pump Model 16C20-QSF2.8P FT4
PREINSTALLATION INSPECTION
The pump assembly was inspected and tested be
fore shipment from the factory. Before installation,
inspect the pump for damage which may have oc
curred during shipment. Check as follows:
a. Inspect the pump for cracks, dents, damaged
threads, and other obvious damage.
b. Check for and tighten loose attaching hard
ware. Since gaskets tend to shrink after dry
ing, check for loose hardware at mating sur
faces.

OM-06755 10 SERIES
PAGE B - 2 INSTALLATION
c. Carefully read all tags, decals, and markings
on the pump assembly, and follow the instruc
tions indicated.
d. Check levels and lubricate as necessary. Re
fer to LUBRICATION in the MAINTENANCE
AND REPAIR section of this manual and per
form duties as instructed.
e. If the pump and engine have been stored for
more than 12 months, some of the compo
nents or lubricants may have exceeded their
maximum shelf life. These must be inspected
or replaced to ensure maximum pump serv
ice.
If the maximum shelf life has been exceeded, or if
anything appears to be abnormal, contact your
Gorman‐Rupp distributor or the factory to deter
mine the repair or updating policy. Do not put the
pump into service until appropriate action has
been taken.
Battery Specifications And Installation
Unless otherwise specified on the pump order, the
engine battery was not included with the unit. Re
fer to the following specifications when selecting a
battery.
Table 1. Battery Specifications
Crank
@ 0_F
Reserve
Capacity
(Minutes)
@ 80_F
Overall
Dims.
(Inches)
960-975 365
20.5L
Cold
Amps
Approx.
Amp/
Hr.
Rating
175 8.75W
9.75H
x
x
Voltage
12 Volts
Refer to the information accompanying the battery
and/or electrolyte solution for activation and charg
ing instructions.
Before installing the battery, clean the positive and
negative cable connectors, and the battery termi
nals. Secure the battery by tightening the hold
down brackets. The terminals and clamps may be
coated with petroleum jelly to retard corrosion.
Connect and tighten the positive cable first, then
the negative cable.
POSITIONING PUMP
Death or serious personal injury and
damage to the pump or components
can occur if proper lifting procedures
are not observed. Make certain that
hoists, chains, slings or cables are in
good working condition and of suffi
cient capacity and that they are posi
tioned so that loads will be balanced
and the pump or components will not be
damaged when lifting. Suction and dis
charge hoses and piping must be re
moved from the pump before lifting. Lift
the pump or component only as high as
necessary and keep personnel away
from suspended objects.
Lifting
Pump unit weights will vary depending on the
mounting and drive provided. Check the shipping
tag on the unit packaging for the actual weight, and
use lifting equipment with appropriate capacity.
Drain the pump and remove all customer‐installed
equipment such as suction and discharge hoses
or piping before attempting to lift existing, installed
units.
Mounting
Locate the pump in an accessible place as close as
practical to the liquid being pumped. Level mount
ing is essential for proper operation.
If the pump has been mounted on a movable base,
make certain the base is stationary by setting the
brake and blocking the wheels before attempting
to operate the pump.
To ensure sufficient lubrication and fuel supply to
the engine, do not position the pump and engine
more than 15_off horizontal for continuous opera
tion. The pump and engine may be positioned up
to 30_off horizontal for intermittent operation
only; however, the engine manufacturer should be
consulted for continuous operation at angles
greater than 15_.

OM-0675510 SERIES
PAGE B - 3INSTALLATION
Clearance
When positioning the pump, allow a minimum
clearance of 18 inches (457 mm) in front of the
back cover to permit removal of the cover and easy
access to the pump interior.
SUCTION AND DISCHARGE PIPING
Pump performance is adversely effected by in
creased suction lift, discharge elevation, and fric
tion losses. See the performance curve and oper
ating range shown on Page E‐1 to be sure your
overall application allows pump to operate within
the safe operation range.
Materials
Either pipe or hose maybe used for suction and
discharge lines; however, the materials must be
compatible with the liquid being pumped. If hose is
used in suction lines, it must be the rigid‐wall, rein
forced type to prevent collapse under suction. Us
ing piping couplings in suction lines is not recom
mended.
Line Configuration
Keep suction and discharge lines as straight as
possible to minimize friction losses. Make mini
mum use of elbows and fittings, which substan
tially increase friction loss. If elbows are necessary,
use the long‐radius type to minimize friction loss.
Connections to Pump
Before tightening a connecting flange, align it ex
actly with the pump port. Never pull a pipe line into
place by tightening the flange bolts and/or cou
plings.
Lines near the pump must be independently sup
ported to avoid strain on the pump which could
cause excessive vibration, decreased bearing life,
and increased shaft and seal wear. If hose‐type
lines are used, they should have adequate support
to secure them when filled with liquid and under
pressure.
Gauges
Most pumps are drilled and tapped for installing
discharge pressure and vacuum suction gauges. If
these gauges are desired for pumps that are not
tapped, drill and tap the suction and discharge
lines not less than 18 inches (457,2 mm) from the
suction and discharge ports and install the lines.
Installation closer to the pump may result in erratic
readings.
SUCTION LINES
To avoid air pockets which could affect pump prim
ing, the suction line must be as short and direct as
possible. When operation involves a suction lift, the
line must always slope upward to the pump from
the source of the liquid being pumped; if the line
slopes down to the pump at any point along the
suction run, air pockets will be created.
Fittings
Suction lines should be the same size as the pump
inlet. If reducers are used in suction lines, they
should be the eccentric type, and should be in
stalled with the flat part of the reducers uppermost
to avoid creating air pockets. Valves are not nor
mally used in suction lines, but if a valve is used,
install it with the stem horizontal to avoid air pock
ets.
Strainers
If a strainer is furnished with the pump, be certain
to use it; any spherical solids which pass through a
strainer furnished with the pump will also pass
through the pump itself.
If a strainer is not furnished with the pump, but is
installed by the pump user, make certain that the
total area of the openings in the strainer is at least
three or four times the cross section of the suction
line, and that the openings will not permit passage
of solids larger than the solids handling capability
of the pump.
This pump is designed to handle up to 3 inch (76,2
mm) diameter spherical solids.
Sealing
Since even a slight leak will affect priming, head,
and capacity, especially when operating with a

OM-06755 10 SERIES
PAGE B - 4 INSTALLATION
high suction lift, all connections in the suction line
should be sealed with pipe dope to ensure an air
tight seal. Follow the sealant manufacturer's rec
ommendations when selecting and applying the
pipe dope. The pipe dope should be compatible
with the liquid being pumped.
Suction Lines In Sumps
If a single suction line is installed in a sump, it
should be positioned away from the wall of the
sump at a distance equal to 1 1/2 times the diame
ter of the suction line.
If there is a liquid flow from an open pipe into the
sump, the flow should be kept away from the suc
tion inlet because the inflow will carry air down into
the sump, and air entering the suction line will re
duce pump efficiency.
If it is necessary to position inflow close to the suc
tion inlet, install a baffle between the inflow and the
suction inlet at a distance 1 1/2 times the diameter
of the suction pipe. The baffle will allow entrained
air to escape from the liquid before it is drawn into
the suction inlet.
If two suction lines are installed in a single sump,
the flow paths may interact, reducing the efficiency
of one or both pumps. To avoid this, position the
suction inlets so that they are separated by a dis
tance equal to at least 3 times the diameter of the
suction pipe.
Suction Line Positioning
The depth of submergence of the suction line is
critical to efficient pump operation. Figure 2 shows
recommended minimum submergence vs. veloc
ity.
NOTE
The pipe submergence required may be reduced
by installing a standard pipe increaser fitting at the
end of the suction line. The larger opening size will
reduce the inlet velocity. Calculate the required
submergence using the following formula based
on the increased opening size (area or diameter).
Figure 2. Recommended Minimum Suction Line Submergence vs. Velocity

OM-0675510 SERIES
PAGE B - 5INSTALLATION
DISCHARGE LINES
Siphoning
Do not terminate the discharge line at a level lower
than that of the liquid being pumped unless a si
phon breaker is used in the line. Otherwise, a si
phoning action causing damage to the pump
could result.
Valves
If a throttling valve is desired in the discharge line,
use a valve as large as the largest pipe to minimize
friction losses. Never install a throttling valve in a
suction line.
With high discharge heads, it is recommended that
a throttling valve and a system check valve be in
stalled in the discharge line to protect the pump
from excessive shock pressure and reverse rota
tion when it is stopped.
If the application involves a high discharge
head, gradually close the discharge
throttling valve before stopping the pump.
Bypass Lines
Self‐priming pumps are not air compressors. Dur
ing the priming cycle, air from the suction line must
be vented to atmosphere on the discharge side. If
the discharge line is open, this air will be vented
through the discharge. However, if a check valve
has been installed in the discharge line, the dis
charge side of the pump must be opened to atmos
pheric pressure through a bypass line installed be
tween the pump discharge and the check valve. A
self‐priming centrifugal pump will not prime if
there is sufficient static liquid head to hold the dis
charge check valve closed.
NOTE
The bypass line should be sized so that it does not
affect pump discharge capacity; however, the by
pass line should be at least 1 inch (25,4 mm) in di
ameter to minimize the chance of plugging.
In low discharge head applications (less than 30
feet (9,1 m)), it is recommended that the bypass
line be run back to the wet well, and located 6
inches below the water level or cut‐off point of the
low level pump. In some installations, this bypass
outline may be terminated with a six‐to‐eight foot
(1,8 to 2,4 m) length of 1‐1/4 inch (31,8 mm) I.D.
smooth‐bore hose; air and liquid vented during
the priming process will then agitate the hose and
break up any solids, grease, or other substances
likely to cause clogging.
A bypass line that is returned to a wet well
must be secured against being drawn into
the pump suction inlet.
It is also recommended that pipe unions be in
stalled at each 90_elbow in a bypass line to ease
disassembly and maintenance.
In high discharge head applications (more than
30 feet (9,1 m), an excessive amount of liquid may
be bypassed and forced back to the wet well under
the full working pressure of the pump; this will re
duce overall pumping efficiency. Therefore, it is
recommended that a Gorman‐Rupp Automatic
Air Release Valve be installed in the bypass line.
Gorman‐Rupp Automatic Air Release Valves are
reliable, and require minimum maintenance. See
Automatic Air Release Valves in this section for
installation and theory of operation of the Auto
matic Air Release Valve. Consult your Gorman‐
Rupp distributor, or contact the Gorman‐Rupp
Company for selection of an Automatic Air Release
Valve to fit your application.
Except in certain specific applications (to
prevent flooding during service of an auto
matic air release valve in a below‐ground
lift station), if a manual shut‐off valve is in
stalled anywhere in a bypass line, it must
be a full‐opening, ball‐type valve to pre
vent plugging by solids.

OM-06755 10 SERIES
PAGE B - 6 INSTALLATION
A manual shut‐off valve should not be installed
in any bypass line. A manual shut‐off valve may
inadvertently be left closed during operation. A
pump which has lost prime may continue to op
erate without reaching prime, causing danger
ous overheating and possible explosive rupture
of the pump casing. Personnel could be severe
ly injured.
Allow an over‐heated pump to completely cool
before servicing. Do not remove plates, covers,
gauges, or fittings from an over‐heated pump.
Liquid within the pump can reach boiling tem
peratures, and vapor pressure within the pump
can cause parts being disengaged to be ejected
with great force. After the pump completely
cools, drain the liquid from the pump by remov
ing the casing drain plug. Use caution when re
moving the plug to prevent injury to personnel
from hot liquid.
AUTOMATIC AIR RELEASE VALVE
When properly installed, a Gorman‐Rupp Auto
matic Air Release Valve will permit air to escape
through the bypass line and then close automati
cally when the pump is fully primed and pumping
at full capacity.
Some leakage (1 to 5 gallons [3.8 to 19
liters] per minute) will occur when the
valve is fully closed. Be sure the bypass
line is directed back to the wet well or
tank to prevent hazardous spills.
Consult the manual accompanying the Air Release
Valve for additional information on valve installation
and performance.
Air Release Valve Installation
The Automatic Air Release Valve must be inde
pendently mounted in a horizontal position be
tween the pump discharge port and the inlet side of
the discharge check valve (see Figure 3). The inlet
opening in the Air Release Valve is equipped with
standard 1‐inch NPT pipe threads.
DISCHARGE PIPE
DISCHARGE
CHECK VALVE
PUMP DISCHARGE
SELF‐PRIMING
CENTRIFUGAL
PUMP
SUCTION
LINE
SUPPORT
BRACKET
CLEAN‐OUT
COVER
INSTALL AIR RELEASE VALVE
IN HORIZONTAL POSITION
90_LONG
RADIUS
ELBOW
WET WELL
OR SUMP
BLEED LINE 1”
(25,4 MM) DIA. MIN.
(CUSTOMER FUR
NISHED) DO NOT EX
TEND BELOW PUMP
OFF LIQUID LEVEL
Figure 3. Typical Automatic Air Release Valve Installation

OM-0675510 SERIES
PAGE B - 7INSTALLATION
Connect the valve outlet to a bleed line which
slopes back to the wet well or sump. The bleed line
must be the same size as the outlet opening or
larger, depending on which Air Release Valve is be
ing used. If piping is used for the bleed line, avoid
the use of elbows whenever possible.
NOTE
For multiple pump installations, it is recommended
that each Air Release Valve be fitted with an inde
pendent bleeder line directed back to the wet well.
If multiple Air Release Valves are installed in a sys
tem, do not direct bleeder lines to a common mani
fold pipe. Contact your Gorman‐Rupp distributor or
the Gorman‐Rupp Company for information about
installation of an Automatic Air Release Valve for
your specific application.
ALIGNMENT
The alignment of the pump and the engine is criti
cal for trouble‐free mechanical operation. See Sec
tion E, Securing Intermediate and Drive Assem
bly To Engine for detailed information.

OM-06755
10 SERIES
OPERATION PAGE C - 1
OPERATION - SECTION C
OPERATION
Review all SAFETY information in Section A.
Follow the instructions on all tags, labels and
decals attached to the pump.
Do not operate an internal combustion
engine in an explosive atmosphere.
When operating an internal combustion
engine in an enclosed area, make sure
exhaust fumes are piped to the outside.
These fumes contain carbon monoxide,
a deadly gas that is colorless, tasteless
and odorless.
This pump is designed to handle most
non‐volatile, non‐flammable liquids
containing specified entrained solids
and corrosives. Do not attempt to pump
volatile, corrosive, or flammable liquids
which may damage the pump or endan
ger personnel as a result of pump fail
ure.
Pump speed and operating condition
points must be within the continuous per
formance range shown on the perfor
mance curve on page E-1.
STARTING
Check the fuel level and oil levels in the engine, air
compressor, pump bearings and seal housing.
Make sure the pump is level. Lower the jack stands
and chock the wheels, if so equipped.
Make sure the pump is level. Lower jack
stands and chock the wheels, if so
equipped. Use caution when positioning
the skid‐mounted unit to prevent damage
to the fuel tank.
This pump is equipped with automatic
liquid level controls, and is subject to
automatic restart. Keep hands and
clothing away from the unit to prevent
injury during automatic operation. Dis
connect the positive battery cable be
fore performing any maintenance. Fail
ure to do so may result in serious per
sonal injury.
Consult the engine operations manual before at
tempting to start the unit.
Consult the manual accompanying the engine
control box and start the pump.
PRIMING
Install the pump and piping as described in IN
STALLATION. Make sure that the piping connec
tions are tight, and that the pump is securely
mounted. Check that the pump is properly lubri
cated (see LUBRICATION in MAINTENANCE
AND REPAIR).
This pump is self‐priming, but the pump should
never be operated unless there is liquid in the
pump casing.
Never operate this pump unless there is
liquid in the pump casing. The pump will
not prime when dry. Extended operation of
a dry pump will destroy the seal assembly.

OM-06755 10 SERIES
OPERATIONPAGE C - 2
Add liquid to the pump casing when:
1. The pump is being put into service for the
first time.
2. The pump has not been used for a consider
able length of time.
3. The liquid in the pump casing has evapo
rated.
Once the pump casing has been filled, the pump
will prime and reprime as necessary.
After filling the pump casing, reinstall
and tighten the fill plug. Do not attempt
to operate the pump unless all connect
ing piping is securely installed. Other
wise, liquid in the pump forced out un
der pressure could cause injury to per
sonnel.
To fill the pump, remove the pump casing fill cover
or fill plug in the top of the casing, and add clean
liquid until the casing is filled. Replace the fill cover
or fill plug before operating the pump.
NOTE
This pump is self‐priming; however, it is not suited
for unattended reprime applications. In the event of
suction check valve failure and loss of prime, the
pump casing must be refilled through the fill cover
or fill plug.
ROUTINE OPERATION
Adjust the engine speed to achieve the desired
output. Do not exceed the factory set engine speed
and system operating pressure. Do not operate
below the recommended operating speed (if appli
cable).
Never tamper with the governor to gain
more power. The governor establishes
safe operating limits that should not be
exceeded. Refer to the Performance
Curve in Section E for the maximum
continuous operating speed for this
pump.
A Gorman‐Rupp automatic air release valve may
be installed in a bypass line, or the bypass line may
be left open.
A manual shut‐off valve should not be
installed in any bypass line. A manual
shut‐off valve may inadvertently be left
closed during operation. A pump which
has lost prime may continue to operate
without reaching prime, causing dan
gerous overheating and possible explo
sive rupture of the pump casing. Per
sonnel could be severely injured.
Lines With a Bypass
If a Gorman‐Rupp Automatic Air Release Valve has
been installed, the valve will automatically open to
allow the pump to prime, and automatically close
after priming is complete (see INSTALLATION for
Air Release Valve operation).
If the bypass line is open, air from the suction line
will be discharged through the bypass line back to
the wet well during the priming cycle. Liquid will
then continue to circulate through the bypass line
while the pump is in operation.
Lines Without a Bypass
Open all valves in the discharge line and start the
engine. Priming is indicated by a positive reading
on the discharge pressure gauge or by a quieter
operation. The pump may not prime immediately
because the suction line must first fill with liquid. If
the pump fails to prime within five minutes, stop it
and check the suction line for leaks.
After the pump has been primed, partially close the
discharge line throttling valve in order to fill the line
slowly and guard against excessive shock pres
sure which could damage pipe ends, gaskets,
sprinkler heads, and any other fixtures connected
to the line. When the discharge line is completely
filled, adjust the throttling valve to the required flow
rate.

OM-06755
10 SERIES
OPERATION PAGE C - 3
Do not operate the pump against a
closed discharge throttling valve for
long periods of time. If operated against
a closed discharge throttling valve,
pump components will deteriorate, and
the liquid could come to a boil, build
pressure, and cause the pump casing to
rupture or explode.
OPERATION IN EXTREME HEAT
The safety shutdown system will automatically
stop the unit if engine operating temperature ex
ceeds design limits. If engine over‐temperature
shutdown occurs, allow the unit to cool before re
starting.
If engine overheating continues, check the engine
lubricant level and viscosity. Consult the engine
operation manual for the recommended lubricant
for operation in extreme heat.
OPERATIONAL CHECKS
Leakage
Once the pump is fully primed, no leakage should
be visible at pump mating surfaces, or at pump
connections or fittings. Keep all line connections
and fittings tight to maintain maximum pump effi
ciency.
Pump Vacuum Check
Read the vacuum gauge with the pump primed
and at operation speed. Shut off the pump. The
vacuum gauge reading will immediately drop pro
portionate to static suction lift, and should then sta
bilize. If the vacuum reading falls off rapidly after
stabilization, an air leak exists. Before checking for
the source of the leak, check the point of installa
tion of the vacuum gauge.
Liquid Temperature And Overheating
The maximum liquid temperature for this pump is
160_F (71_C). Do not apply it at a higher operating
temperature.
Overheating can occur if operated with the valves
in the suction or discharge lines closed. Operating
against closed valves could bring the liquid to a
boil, build pressure, and cause the pump to rup
ture or explode. If overheating occurs, stop the
pump immediately and allow it to completely cool
before servicing it. Approach any over‐heated
pump cautiously.
Allow an over‐heated pump to com
pletely cool before servicing. Do not re
move plates, covers, gauges, or fittings
from an overheated pump. Liquid within
the pump can reach boiling tempera
tures, and vapor pressure within the
pump can cause parts being disen
gaged to be ejected with great force. Af
ter the pump cools, drain the liquid from
the pump by removing the casing drain
plug. Use caution when removing the
plug to prevent injury to personnel from
hot liquid.
Strainer Check
Check the strainer regularly, and clean it as neces
sary. The strainer should also be checked if pump
flow rate begins to drop. Monitor and record the
vacuum suction gauge readings regularly to detect
strainer blockage.
Never introduce air or steam pressure into the
pump casing or piping to remove a blockage. This
could result in personal injury or damage to the
equipment. If backflushing is absolutely neces
sary, liquid pressure must be limited to 50% of the
maximum permissible operating pressure shown
on the pump performance curve.
STOPPING
Never halt the flow of liquid suddenly. If the liquid
being pumped is stopped abruptly, damaging

OM-06755 10 SERIES
OPERATIONPAGE C - 4
shock waves can be transmitted to the pump and
piping system. Close all connecting valves slowly.
Stopping
Reduce the throttle speed slowly, and allow the en
gine to idle briefly before turning the keyswitch to
`OFF'.
If the application involves a high discharge
head, gradually close the discharge
throttling valve before stopping the pump.
After stopping the pump, close and lock the control
panel cover, or disconnect the positive battery
cable to ensure that the pump will remain inopera
tive.
Safety Shutdown System
The unit is equipped with a safety system to auto
matically shut down the engine under certain con
ditions.
Displays on the control panel will indicate which of
the safety features has caused the engine to shut
down.
Should any of the safety features cause the engine
to shut down, the cause must be determined and
corrected before putting the unit back into service.
All safety shutdown features are pre‐set at the fac
tory for optimum performance and safety; do not
attempt to adjust these settings.
Never disconnect any of the safety shut
down features; this will void the warran
ty and could result in serious damage to
the unit and/or injury to personnel. Safe
ty shutdown features are pre‐set at the
factory; do not attempt to adjust any of
the settings. Determine the cause of
shutdown before putting the unit back
into service. Consult the factory for ad
ditional information.
PERIODIC CHECKS
Seal Cavity and Bearing Lubrication
Both the seal and bearing cavities were fully lubri
cated at the factory. Check the lubrication levels
before startup and regularly thereafter as indicated
in Section E, Maintenance and Repair. When lu
brication is required, use only SAE No. 30 non‐det
ergent oil.
Bearing Temperature Check
Bearings normally run at higher than ambient tem
peratures because of heat generated by friction.
Temperatures up to 160_F (71_C) are considered
normal for bearings, and they can operate safely to
at least 180_F (82_C).
Checking bearing temperatures by hand is inaccu
rate. Bearing temperatures can be measured ac
curately by placing a contact‐type thermometer
against the housing. Record this temperature for
future reference.
A sudden increase in bearing temperatures is a
warning that the bearings are at the point of failing
to operate properly. Make certain that the bearing
lubricant is of the proper viscosity and at the cor
rect level (see LUBRICATION in Section E, Main
tenance and Repair). Bearing overheating can
also be caused by shaft misalignment and/or ex
cessive vibration.
When pumps are first started, the bearings may
seem to run at temperatures above normal. Con
tinued operation should bring the temperatures
down to normal levels.
Engine Fuel Filter
Consult the manual accompanying the engine,
and change the fuel filter periodically as indicated.
If operated under extremely dusty and/or humid
conditions, change the filter more frequently. Irreg
ular performance and loss of power usually indi
cate a dirty fuel filter.
Engine Oil
The engine was lubricated for test at the factory.
However, always check the lubrication level before
startup.

OM-06755
10 SERIES
OPERATION PAGE C - 5
Consult the manual accompanying the engine,
and change the oil filter periodically as indicated. If
operated under extremely dusty conditions,
change the filter more frequently.
COLD WEATHER PRESERVATION
In below freezing conditions, drain the pump to
prevent damage from freezing. Also, clean out any
solids by flushing with a hose. Operate the pump
for approximately one minute; this will remove any
remaining liquid that could freeze the pump rotat
ing parts. If the pump will be idle for more than a
few hours, or if it has been pumping liquids con
taining a large amount of solids, drain the pump,
and flush it thoroughly with clean water. To prevent
large solids from clogging the drain port and pre
venting the pump from completely draining, insert
a rod or stiff wire in the drain port, and agitate the
liquid during the draining process. Clean out any
remaining solids by flushing with a hose.

10 SERIES OM-06755
TROUBLESHOOTING PAGE D - 1
TROUBLESHOOTING - SECTION D
Review all SAFETY information in Section A.
Before attempting to open or service the
pump:
1. Familiarize yourself with this manual.
2. Switch off the engine ignition and dis
connect the positive battery cable to
ensure that the pump will remain in
operative.
3. Allow the pump to completely cool if
overheated.
4. Check the temperature before open
ing any covers, plates, or plugs.
5. Close the suction and discharge
valves.
6. Vent the pump slowly and cautiously.
7. Drain the pump.
TROUBLE POSSIBLE CAUSE PROBABLE REMEDY
PUMP FAILS TO
PRIME Suction check valve contaminated or
damaged.
Clean or replace check valve.
Air leak in suction line.
Lining of suction hose collapsed.
Correct leak.
Replace suction hose.
Leaking or worn seal or pump gasket. Check pump vacuum. Replace
leaking or worn seal or gasket.
Suction lift or discharge head too high. Check piping installation and in
stall bypass line if needed. See
INSTALLATION.
Strainer clogged. Check strainer and clean if neces
sary.
Not enough liquid in casing. Add liquid to casing. See PRIMING.
Suction check valve or foot valve
clogged or binding.
Clean valve
PUMP STOPS OR
FAILS TO DELIVER
RATED FLOW OR
PRESSURE
Air leak in suction line.
Lining of suction hose collapsed.
Correct leak.
Replace suction hose.
Leaking or worn seal or pump gasket. Check pump vacuum. Replace
leaking or worn seal or gasket.
Strainer clogged. Check strainer and clean if neces
sary.