GORMAN-RUPP PUMPS O Series Application guide

OM-01193-02
January 23, 1981
Rev. G 11‐17‐16
GORMAN‐RUPP PUMPS
www.grpumps.com
e1981 Gorman‐Rupp Pumps Printed in U.S.A.
INSTALLATION, OPERATION,
AND MAINTENANCE MANUAL
WITH PARTS LIST
0 SERIES PUMP
MODEL
03H1-GL

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Please record your pump model and serial number in the
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needs this information when you require parts or service.
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Serial Number:

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 - 2............................................
VEHICLE REQUIREMENTS PAGE B - 2.................................................
Tank Preparation PAGE B - 2.......................................................
POSITIONING PUMP PAGE B - 2.......................................................
Lifting PAGE B - 2.................................................................
ALIGNMENT PAGE B - 3..............................................................
SUCTION AND DISCHARGE PIPING PAGE B - 4.........................................
Piping PAGE B - 5................................................................
Sealing PAGE B - 6...............................................................
Valves PAGE B - 6................................................................
Siphoning PAGE B - 7.............................................................
Eductors PAGE B - 7..............................................................
OPERATION - SECTION C PAGE C - 1......................................
PRIMING PAGE C - 1.................................................................
GROUNDING PAGE C - 1.............................................................
STARTING PAGE C - 1................................................................
Rotation PAGE C - 1..............................................................
Drive PAGE C - 2.................................................................
OPERATION PAGE C - 2..............................................................
Leakage PAGE C - 2..............................................................
Liquid Temperature And Overheating PAGE C - 2.....................................
Strainer Check PAGE C - 2.........................................................
Pump Vacuum Check PAGE C - 3..................................................
STOPPING PAGE C - 3................................................................
Cold Weather Preservation PAGE C - 3..............................................
GEARBOX TEMPERATURE CHECK PAGE C - 3..........................................
TROUBLESHOOTING - SECTION D PAGE D - 1..............................
PUMP MAINTENANCE AND REPAIR ‐ SECTION E PAGE E - 1.................
PERFORMANCE CURVE PAGE E - 1...................................................
PARTS LISTS:
Pump Model PAGE E - 3..........................................................
Gearbox Assembly PAGE E - 5.....................................................
PUMP AND SEAL DISASSEMBLY AND REASSEMBLY PAGE E - 6.........................
Removing Pump and Gearbox PAGE E - 6...........................................
Pump Casing and Wear Ring Removal PAGE E - 7....................................
Impeller Removal PAGE E - 7......................................................
Seal Removal and Disassembly PAGE E - 7..........................................

TABLE OF CONTENTS
(continued)
ii
PUMP AND SEAL REASSEMBLY PAGE E - 7............................................
Seal Reassembly and Installation PAGE E - 7........................................
Impeller Installation PAGE E - 9.....................................................
Pump Casing and Wear Ring Installation PAGE E - 9..................................
Installing Pump and Gearbox PAGE E - 10............................................
GEARBOX DISASSEMBLY PAGE E - 10..................................................
GEARBOX REASSEMBLY PAGE E - 11...................................................
LUBRICATION PAGE E - 13.............................................................
Seal Assembly PAGE E - 13.........................................................
Gearbox PAGE E - 13..............................................................

0 SERIES OM-01193
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.

0 SERIES OM‐01193
PAGE A - 1SAFETY
SAFETY - SECTION A
This information applies to 0 Series
power take‐off pumps. Refer to the man
ual accompanying the power source be
fore attempting 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 vehicle ignition and
remove the key 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 for vehicular
mounting in petroleum service. Do not
attempt to pump corrosive materials
which may damage the pump or endan
ger personnel as a result of pump fail
ure.
If this pump is used with volatile and/or
flammable liquids, be certain proper
safety practices are followed before op
erating or servicing the pump. Provide
adequate ventilation, prohibit smoking,
wear static‐resistant clothing and
shoes. Clean up all fuel spills immedi
ately after occurrence.
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 connections are tight, properly sup
ported and secure before operation.
Do not operate the pump without the
shields and/or guards in place over the
rotating parts. Exposed rotating parts

0 SERIESOM-01193
PAGE A - 2 SAFETY
can catch clothing, fingers, or tools,
causing severe injury to personnel.
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.
If this pump is used with volatile and/or
flammable liquids, overheating may
produce dangerous fumes. Take pre
cautions to ensure the area surrounding
the pump is adequately ventilated. Al
low the pump to cool and use extreme
caution when venting the pump, or
when removing covers, plates, plugs, or
fitting.
Overheated pumps can cause severe
burns and injuries. If overheating of the
pump occurs:
1. Stop the pump immediately.
2. Ventilate the area.
3. Allow the pump to completely cool.
4. Check the temperature before
opening any covers, plates,
gauges, or plugs.
5. Vent the pump slowly and cau
tiously.
6. Refer to instructions in this manual
before restarting the pump.
After the vehicle is positioned for pump
maintenance, block the wheels and set
the emergency brake before attempting
to disconnect the drive shaft or remove
the pump. Be sure the pump is properly
reinstalled and secure before opera
tion.
Do not remove plates, covers, gauges,
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 completely cool before
servicing.
The gearbox provided on this pump is
designed for operation at 1000 RPM
maximum input speed. If operated at a
higher RPM, pump components may be
destroyed.
Never run this pump backwards. Be cer
tain that rotation is correct before fully
engaging the pump.
Never run the pump dry of pumping me
dium. There must be a supply of liquid to
the pump at all times to prevent destruction
of the shaft seal faces.
Pumps and related equipment must be in
stalled and operated according to all na
tional, local and industry standards.

0 SERIES OM-01193
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.
Do not test or operate your pump and in
tegral gearbox before reading the in
stallation and operation instructions in
this manual.
This pump is a self‐priming centrifugal model with
an integral gearbox assembly. It is designed for ve
hicular mounting in petroleum service, where the
liquid is supplied to the pump under pressure.
Since the pressure supplied to the pump is critical
to performance and safety, be sure to limit the in
coming pressure to 50% of the maximum permissi
ble operating pressure as shown on the pump per
formance curve (see Section E, Page 1).
The integral gearbox is designed to be driven
through the vehicle transfer case by a customer‐
supplied universal shaft assembly. The pump cas
ing or gearbox may be rotated in 45_increments to
assist with alignment with the vehicle tank; howev
er, if the gearbox is to be rotated, some modifica
tions must be made to the gearbox to ensure ade
quate lubrication. Consult the factory for details.
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 03H1‐GL

OM-01193 0 SERIES
PAGE B - 2 INSTALLATION
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 and gearbox 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.
c. Carefully read all tags, decals, and markings
on the pump assembly, and perform all duties
indicated. Note the direction of rotation indi
cated on the pump. Check that the pump
shaft rotates in the required direction.
Only operate this pump in the direction in
dicated on the pump body and/or the ac
companying decal. Reverse rotation of the
shaft will adversely effect pump perform
ance, and the pump and/or gearbox could
be seriously damaged.
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 gearbox 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.
VEHICLE REQUIREMENTS
The following instructions apply equally to new in
stallations, rebuilds or retrofits.
Tank Preparation
It is essential that any tank scale, dirt, or other for
eign material be removed from the tank and piping
prior to pump installation. Failure to do so could re
sult in clogging or damage to the pump.
Damage to the pump resulting from debris
in the suction line will not be covered by
the pump warranty.
Before connecting the suction and dis
charge piping, carefully check the storage
tank and piping for construction debris
such as nuts, bolts, wire, weld slag, and
other foreign material. Install a commer
cially available 80 mesh screen in the suc
tion line to prevent debris from entering the
pump.
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.

0 SERIES OM-01193
PAGE B - 3INSTALLATION
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.
The pump assembly can be seriously
damaged if the cables or chains used to lift
and move the unit are improperly wrapped
around the pump.
Due to the confined mounting location,
specialized equipment such as a transmis
sion jack with custom brackets should be
used to lift and position the pump and
gearbox.
NOTE
If the gearbox is rotated out of the standard position
shown in Figure 1, the oil fill and drain plugs must
be relocated. The oil vent must be relocated to the
highest port. Consult the factory for correct posi
tioning of the fill plug to provide for proper lubrica
tion of the gearbox.
ALIGNMENT
When installing and/or aligning univer
sal shaft assemblies, disconnect the
power source to ensure that the pump
will remain inoperative.
The alignment of the pump and its power source is
critical for trouble‐free mechanical operation. Be
fore checking alignment, make sure that the gear
box mounting bolts are tight.
When connecting the universal joint drive shaft as
sembly to a PTO unit, install, support, and align the
drive shaft in accordance with the manufacturer's
instructions. The pump and the drive power source
are generally positioned so that shaft centerlines
are parallel and horizontal. The maximum operat
ing angle should not exceed 15_(see Figure 2).
Check the direction of rotation of the PTO unit be
fore starting the pump. The drive shaft must rotate
in the direction shown on the body of the pump,
gearbox, and/or decals, tags, and labels.
Do not operate the pump without the
guard in place over the rotating parts.
Exposed rotating parts can catch cloth
ing, fingers, or tools, causing severe in
jury to personnel.
After the power take‐off has been aligned, block
the wheels of the external power source, engage
the braking system, or take other precautions to
ensure that the power source will remain station
ary. Block the wheels on the unit to prevent creep
ing.

OM-01193 0 SERIES
PAGE B - 4 INSTALLATION
LUG ALIGNMENT
SHAFTS PARALLEL, ANGLES EQUAL
SHAFTS NOT PARALLEL, ANGLES EQUAL
LUGS MUST BE IN LINE, REGARDLESS
OF OPERATING ANGLE SHOWN BELOW
Figure 2. Proper Installation And Alignment of Universal Assembly
SUCTION AND DISCHARGE PIPING
Typical System Installation
Tank filling and dispensing operations require a
system utilizing flow‐directing (FDF) valves, educ
tors, related piping and safety accessories. Some
of the accessories are available from Gorman‐
Rupp as optional equipment.
Refer to Figures 3 and 4 for illustrations of typical
piping systems for tank filling and dispensing.

0 SERIES OM-01193
PAGE B - 5INSTALLATION
SCHEMATIC SYSTEM USING EDUCTOR FOR DISPENSING AND FILLING
Figure 3. Typical Installation Using Educator For Filling And Dispensing
SCHEMATIC SYSTEM USING PUMP FOR DISPENSING AND FILLING
Figure 4. Typical Installation Using Pump For Filling And Dispensing
Piping
All piping material must be compatible with the liq
uid being pumped. If hose is used in suction lines,
it must be the rigid‐wall, reinforced type to prevent
collapse under suction. Using piping couplings in
suction lines is not recommended.
A suction strainer was not furnished with this pump
since it is not designed to handle liquids containing
solids. However, to protect the pump from acciden
tal damage a commercially available 80 mesh
screen should be installed in the suction line. Make
certain that the total open area of the screen is at
least three or four times the cross section of the

OM-01193 0 SERIES
PAGE B - 6 INSTALLATION
suction line to ensure an adequate supply of liquid
to the pump.
Damage To the pump resulting from debris
in the suction line will not be covered by
the pump warranty.
Before connecting the suction and dis
charge piping, carefully check the storage
tank and piping for construction debris
such as nuts, bolts, wire, weld slag, and
other foreign material. Install a commer
cially available 80 mesh screen in the suc
tion line to prevent debris from entering the
pump.
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.
Sealing
Since even a slight leak will affect priming, head,
and capacity, especially when operating with a
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
pie dope.
Valves
Gorman‐Rupp manufactures several sizes of flow‐
diverting (FDF) valves for use in truck‐mounted
pumping applications. The valves are designed to
reverse the flow of liquid with only the turn of a han
dle. This allows the same pump to fill or dispense
from the tank.
The FDF valve is designed for directing
flow only. it will not serve as a positive shut
off or throttling valve.
See Figure 5 illustrating the theory of operation for
a typical FDF valve. Consult the factory for further
assistance or other sizes.
FILL
POSITION
DISPENSE FILLTOP VIEW
DISPENSING
POSITION
Figure 5. FDF Valve Theory of Operation
When the center web of the valve is aligned with the
larger ports (filling position), the flow passes
straight through. When the handle is turned to the
dispensing position, the web blocks the straight
flow and opens two paths of flow through the larger
ports to the smaller ports.

0 SERIES OM-01193
PAGE B - 7INSTALLATION
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.
Eductors
An eductor may be used in conjunction with an
FDF valve to increase dispensing rates and im
prove efficiency. An educator may also be used to
collapse the tank service hose after the tank has
been filled or emptied.
Contact the Gorman‐Rupp Company or an autho
rized distributor for specifications and perform
ance data on eductors or FDF valves.

OM-01193
0 SERIES
OPERATION PAGE C - 1
OPERATION - SECTION C
Review all SAFETY information in Section A.
Follow the instructions on all tags, labels and
decals attached to the pump.
This pump is designed for vehicular
mounting in petroleum service. Do not
attempt to pump corrosive materials, or
any liquids which may damage the
pump or endanger personnel as a result
of pump failure.
The gearbox provided on this pump is
designed for operation at 1000 RPM
maximum input speed. If operated at a
higher RPM, pump components may be
destroyed.
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.
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.
When installed in a flooded suction application,
simply open the system valves and permit the in
coming liquid to evacuate the air. After the pump
and piping system have completely filled, evacu
ate any remaining air pockets in the pump or suc
tion line by loosening a pipe plug or opening bleed
er valves.
Once the pump casing has been filled, the pump
will prime and reprime as necessary.
GROUNDING
To eliminate electrostatic build‐up when pumping
petroleum products, the pump must be grounded
by attaching a ground wire to a ground rod. Install
the ground rod in accordance with the National
Electric Code and all local codes. Be sure the
clamp or fastener has made a tight electrical con
nection with the rod.
Inspect and test the ground wire assembly
for conductivity. Replace broken or frayed
wire before resuming operation.
STARTING
Consult the operations manual furnished with the
power source.
Rotation
The correct direction of pump rotation is counter
clockwise when facing the input drive shaft. The

OM-01193 0 SERIES
OPERATIONPAGE C - 2
pump could be damaged and performance ad
versely affected by incorrect rotation. If pump per
formance is not within the specified limits (see the
curve on Page E-1), check the direction of rotation
before further troubleshooting.
Drive
This pump is designed for operation with a power
take‐off unit coupled to the drive shaft on the gear
box. The gearbox assembly has a ratio of 4.09:1,
and is designed for operation at 1000 RPM. Do not
operate at a higher input speed.
The gearbox provided on this pump is
designed for operation at 1000 RPM
maximum. If operated at a higher rpm,
pump components may be destroyed.
OPERATION
Pump speed and operating condition
points must be within the continuous per
formance range shown on the curve (see
Section E, Page 1).
Partially open the discharge throttling valve so that
the discharge line fills slowly to prevent damage to
piping, gaskets, and other devices in the line which
could be affected by shock resulting from rapid fill
ing of the line. When the discharge line is com
pletely filled, adjust the discharge throttling valve to
the desired flow rate.
Leakage
No leakage should be visible at pump mating sur
faces, or at pump connections or fittings. Keep all
line connections and fittings tight to maintain maxi
mum pump efficiency.
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 and allow it to cool before servicing it. Refill
the pump casing with cool liquid.
Allow an overheated pump to complete
ly cool before servicing. Do not remove
plates, covers, gauges, pipe plugs, or
fittings from an overheated pump. Liq
uid within the pump can reach boiling
temperatures, and vapor pressure with
in the pump can cause parts being dis
engaged to be ejected with great force.
After 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
If a suction strainer has been shipped with the
pump or installed by the user, check the strainer
regularly, and clean it as necessary. The strainer
should also be checked if pump flow rate begins to
drop. If a vacuum suction gauge has been in
stalled, monitor and record the 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. (See Section E,
Page 1.)

OM-01193
0 SERIES
OPERATION PAGE C - 3
Pump Vacuum Check
Since this pump does not have a suction check
valve, the discharge line must be fitted with a check
valve if a pump vacuum reading is to be taken.
With the pump inoperative, install a vacuum gauge
in the system, using pipe dope on the threads.
Block the suction line and start the pump. At oper
ating speed the pump should pull a vacuum of 20
inches (508,0 mm) or more of mercury. If it does
not, check for air leaks in the seal, gasket, or dis
charge valve.
Open the suction line, and read the vacuum gauge
with the pump primed and at operation speed.
Shut off the pump. The vacuum gauge reading will
immediately drop proportionate to static suction
lift, and should then stabilize. 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 installation of the vacuum gauge.
NOTE
Petroleum products are very sensitive to changes
in temperature. Warmer temperatures elevate the
product vapor pressure, resulting in low vacuum
readings. Do not mistake temperature problems for
faulty pump installation or performance.
STOPPING
Never halt the flow of liquid suddenly. If the liquid
being pumped is stopped abruptly, damaging
shock waves can be transmitted to the pump and
piping system. Close all connecting valves slowly.
On engine driven pumps, reduce the throttle
speed slowly and allow the engine to idle briefly be
fore stopping.
If the application involves a high discharge
head, gradually close the discharge
throttling valve before stopping the pump.
After stopping the pump, remove the engine igni
tion key to ensure that the pump will remain inop
erative.
Cold Weather Preservation
If the application of this pump is limited to petro
leum products, normal freezing conditions will not
damage the pump. However, during extremely se
vere conditions care should be exercised during
start‐up, especially if the pump has been idle for
more than a few hours.
GEARBOX TEMPERATURE CHECK
The gearbox runs higher than ambient tempera
tures because of heat generated by friction. Tem
peratures of approximately 200_F (93_C) are con
sidered normal, and can operate intermittently at
250_F (121_C).
Checking gearbox temperatures by hand is inac
curate. Place a contact‐type thermometer against
the housing and record this temperature for future
reference.
A sudden increase in gearbox temperature is a
warning that the bearings are at the point of failing.
Make certain that the bearing lubricant is of the
proper viscosity and at the correct level (see LU
BRICATION in Section E). Bearing overheating
can also be caused by shaft misalignment and/or
excessive 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 within 20 minutes or less.

TROUBLE POSSIBLE CAUSE PROBABLE REMEDY
PUMP FAILS TO
PRIME
Strainer clogged. Check strainer and clean if neces
sary.
Leaking or worn seal or pump gasket. Check pump vacuum. Replace
leaking or worn seal or gasket.
Lining of suction hose collapsed. Replace suction hose.
Air leak in suction line. Correct leak.
PUMP STOPS OR
FAILS TO DELIVER
RATED FLOW OR
PRESSURE
Air leak in suction line. Correct leak.
Lining of suction hose collapsed. Replace suction hose.
Leaking or worn seal or pump gasket. Check pump vacuum. Replace
leaking or worn seal or gasket.
Suction intake not submerged at
proper level or sump too small.
Check installation and correct
submergence as needed.
Not enough liquid in casing. Add liquid to casing. See
PRIMING.
Pump speed too slow. Check power source output; con
sult power source operation man
ual.
OM-011930 SERIES
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 vehicle ignition and re
move the key, or take other precau
tions to ensure that the pump will re
main inoperative.
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 STOPS OR
FAILS TO DELIVER
RATED FLOW OR
PRESSURE (cont.)
PUMP REQUIRES
TOO MUCH
POWER
Discharge head too low. Adjust discharge valve.
EXCESSIVE NOISE Cavitation in pump. Reduce suction lift and/or friction
losses in suction line. Record vac
uum and pressure gauge readings
and consult local representative or
factory.
Secure mounting hardware.Pump or drive not securely mounted.
Locate and eliminate source of air
bubble.
Pumping entrained air.
Pump speed too high. Check driver output; check that
sheaves or couplings are correctly
sized.
Suction lift or discharge head too high. Check piping installation and install
bypass line if needed. See INSTAL
LATION.
Low or incorrect lubricant. Check for proper type and level of
lubricant.
Pump speed too slow. Check power source output; consult
power source operation manual.
BEARINGS RUN
TOO HOT
Bearing temperature is high, but within
limits.
Check bearing temperature regu
larly to monitor any increase.
Low or incorrect lubricant. Check for proper type and level
of lubricant.
Suction and discharge lines not prop
erly supported.
Check piping installation for proper
support.
Drive misaligned; piping improperly in
stalled.
Bearings in power source or gearbox Check bearings.
worn or binding.
Realign drive and piping at operat
ing temperature. Add expansion
joints if required.
Discharge line clogged or restricted;
hose kinked.
Check discharge lines; straighten
hose.
Universal joint drive misaligned. Align drive.
Universal joint drive misaligned. Align drive.
Impeller or other wearing parts worn
or damaged.
Replace worn or damaged parts.
Check that impeller is properly cen
tered and rotates freely.
OM-01193 0 SERIES
TROUBLESHOOTINGPAGE D - 2

OM-011930 SERIES
TROUBLESHOOTING PAGE D - 3
PREVENTIVE MAINTENANCE
Since pump applications are seldom identical, and
pump wear is directly affected by such things as
the abrasive qualities, pressure and temperature
of the liquid being pumped, this section is intended
only to provide general recommendations and
practices for preventive maintenance. Regardless
of the application however, following a routine pre
ventive maintenance schedule will help assure
trouble‐free performance and long life from your
Gorman‐Rupp pump. For specific questions con
cerning your application, contact your Gorman‐
Rupp distributor or the Gorman‐Rupp Company.
Record keeping is an essential component of a
good preventive maintenance program. Changes
in suction and discharge gauge readings (if so
equipped) between regularly scheduled inspec
tions can indicate problems that can be corrected
before system damage or catastrophic failure oc
curs. The appearance of wearing parts should also
be documented at each inspection for comparison
as well. Also, if records indicate that a certain part
(such as the seal) fails at approximately the same
duty cycle, the part can be checked and replaced
before failure occurs, reducing unscheduled down
time.
For new applications, a first inspection of wearing
parts at 250 hours will give insight into the wear rate
for your particular application. Subsequent inspec
tions should be performed at the intervals shown
on the chart below. Critical applications should be
inspected more frequently.
General Condition (Temperature, Unusual
Noises or Vibrations, Cracks, Leaks,
Loose Hardware, Etc.) I
Pump Performance (Gauges, Speed, Flow) I
Bearing Lubrication I R
Seal Lubrication (And Packing Adjustment,
If So Equipped) I R
V‐Belts (If So Equipped) I
Air Release Valve Plunger Rod (If So Equipped) I C
Front Impeller Clearance (Wear Plate) I
Rear Impeller Clearance (Seal Plate) I
Check Valve I
Pressure Relief Valve (If So Equipped) C
Pump and Driver Alignment I
Shaft Deflection I
Bearings I
Bearing Housing I
Piping I
Driver Lubrication - See Mfgr's Literature
Legend:
I = Inspect, Clean, Adjust, Repair or Replace as Necessary
C = Clean
R = Replace
* Service interval based on an intermittent duty cycle equal to approximately 4000 hours annually.
Adjust schedule as required for lower or higher duty cycles or extreme operating conditions.
Preventive Maintenance Schedule
Item Daily Weekly Monthly Semi‐
Annually
Annually
Service Interval*