GORMAN-RUPP S Series User manual

PUBLICATION NUMBER MR-04319
August 8, 1995
Rev. C 08‐08‐15
GORMAN‐RUPP PUMPS
www.grpumps.com
e1995 Gorman‐Rupp Pumps Printed in U.S.A.
S SERIES PUMPS
S8D
All Materials And Voltages

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:

MR-04319 S SERIES PUMPS
PAGE I - 1INTRODUCTION
INTRODUCTION
Thank You for purchasing a Gorman‐Rupp S
Series Pump. Read this manual carefully to learn
how to safely maintain and service your pump. Fail
ure to do so could result in personal injury or dam
age to the pump.
A set of three manuals accompanies your pump.
The Installation/Operation Manual contains essen
tial information on installing and operating the
pump, and on making electrical connections. The
Parts List Manual provides a performance curve, a
pump model cross‐section drawing, and parts list
for your pump.
This Maintenance and Repair Manual provides
troubleshooting and maintenance instructions re
quired to properly diagnose operational problems,
and to service the pump components. Pump motor
maintenance may be performed only by a Gor
man‐Rupp authorized Submersible repair facility,
or the factory. Otherwise, the pump warranty will be
negated, and damage to the pump, and injury or
death to personnel can result. Contact the factory
for the authorized repair facility closest to you.
As described on the following page, this manual
will alert personnel to known procedures which re
quire special attention, to those which could dam
age equipment, and to those which could be dan
gerous to personnel. However, this manual cannot
possibly anticipate and provide detailed precau
tions for every situation that might occur during
maintenance of the unit. Therefore, it is the respon
sibility of the owner/maintenance personnel to en
sure that only safe, established maintenance pro
cedures are used, and that any procedures not ad
dressed in this manual are performed only after es
tablishing that neither personal safety nor pump in
tegrity are compromised by such practices.
If there are any questions regarding the pump
which are not covered in this manual or in other lit
erature accompanying the unit, please contact
your Gorman‐Rupp distributor or the Gorman‐
Rupp Company:
The Gorman‐Rupp Company
P.O. Box 1217
Mansfield, Ohio 44901-1217
or:
Gorman‐Rupp of Canada Limited
70 Burwell Road
St. Thomas, Ontario N5P 3R7
CONTENTS
SAFETY - SECTION A
TROUBLESHOOTING - SECTION B
ELECTRICAL TESTING PAGE B - 3........................................................
Test Equipment PAGE B - 3...........................................................
Voltage Imbalance PAGE B - 3........................................................
Motor and Power Cable Continuity PAGE B - 4..........................................
Insulation Resistance PAGE B - 4......................................................
PUMP MAINTENANCE AND REPAIR - SECTION C
GENERAL INFORMATION PAGE C - 1.....................................................
Lifting PAGE C - 1....................................................................
TYPICAL PUMP ASSEMBLY PAGE C - 2....................................................
PUMP ASSEMBLY PARTS IDENTIFICATION LIST PAGE C - 3.................................
TERMINAL HOUSING AND CABLE ASSEMBLY PAGE C - 4...................................
TERMINAL HOUSING AND CABLE ASSEMBLY PARTS IDENTIFICATION LIST PAGE C - 5.......
PUMP END DISASSEMBLY PAGE C - 6....................................................
PUMP END REASSEMBLY PAGE C - 9.....................................................
MOTOR DISASSEMBLY PAGE C - 14......................................................
MOTOR REASSEMBLY PAGE C - 17.......................................................
FINAL ASSEMBLY PAGE C - 23...........................................................
VACUUM TESTING PAGE C - 24..........................................................
LUBRICATION PAGE C - 25...............................................................

MR-04319S SERIES PUMPS
PAGE I - 2 INTRODUCTION
RECORDING MODEL AND
SERIAL NUMBERS
Please record the pump model, serial number, volt
age, and motor frame size in the spaces provided
below. Your Gorman‐Rupp distributor needs this
information when you require parts or service.
Pump Model:
Serial Number:
Voltage:
Phase:
WARRANTY INFORMATION
The warranty provided with your pump is part of
Gorman‐Rupp's support program for customers
who operate and maintain their equipment as de
scribed in this and the other accompanying litera
ture. The integral electric motor must be operated
through the control furnished with the pump as
standard equipment. Please note that should the
equipment be abused or modified to change its
performance beyond the original factory specifica
tions, the warranty will become void and any claim
will be denied.
All repairs to the pump motor must be performed
by a Gorman‐Rupp authorized Submersible repair
facility or the factory. Any repairs to the motor as
sembly performed by the customer or an unautho
rized repair facility negates motor warranty.
The following are used to alert personnel to procedures which require special attention, 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 de
scribe the requirements and the possible
damage which could result from failure to
follow the procedure.
NOTE
Instructions to aid in installation, operation, and
maintenance or which clarify a procedure.

MR-04319 S SERIES PUMPS
PAGE A - 1SAFETY
SAFETY - SECTION A
The following information applies
throughout this manual to Gorman‐
Rupp S Series submersible motor driv
en pumps.
This manual will alert personnel to
known procedures which require spe
cial attention, to those which could
damage equipment, and to those which
could be dangerous to personnel. How
ever, this manual cannot possibly antici
pate and provide detailed instructions
and precautions for every situation that
might occur during maintenance of the
unit. Therefore, it is the responsibility of
the owner/maintenance personnel to
ensure that only safe, established main
tenance procedures are used, and that
any procedures not addressed in this
manual are performed only after estab
lishing that neither personal safety nor
pump integrity are compromised by
such practices.
This manual contains essential informa
tion on troubleshooting and maintain
ing the pump. In addition to this manual,
see the separate literature covering in
stallation and operation, pump parts,
and any optional equipment shipped
with the pump.
Before attempting to open or service the
pump:
1. Familiarize yourself with this man
ual.
2. Lock out incoming power to the
control box to ensure that the
pump will remain inoperative.
3. Allow the pump to completely cool
if overheated.
4. Close the discharge valve (if
used).
This pump is not designed to pump vol
atile, explosive, or flammable materials.
Do not attempt to pump any liquids for
which your pump is not approved, or
which may damage the pump or endan
ger personnel as a result of pump fail
ure. Consult the factory for specific
application data.
Before connecting any cable to the con
trol box, be sure to ground the control
box. Refer to the Control Box manual for
the suggested grounding methods.
The pump motor is designed to be oper
ated through the control box furnished
with the pump. The control box provides
overload protection and power control.
Do not connect the pump motor directly
to the incoming power lines.
The electrical power used to operate
this pump is high enough to cause inju
ry or death. Obtain the services of a qu
alified electrician to make all electrical
connections. Make certain that the
pump and enclosure are properly
grounded; never use gas pipe as an
electrical ground. Be sure that the in
coming power matches the voltage and

S SERIES PUMPS MR-04319
PAGE A-2 SAFETY
phase of the pump and control before
connecting the power source. Do not
run the pump if the voltage is not within
the limits. If the overload unit is tripped
during pump operation, correct the
problem before restarting the pump.
The electrical power used to operate
this pump is high enough to cause inju
ry or death. Make certain that the control
handle on the control box is in the OFF
position and locked out, or that the pow
er supply to the control box has been
otherwise cut off and locked out, before
attempting to open or service the pump
assembly. Tag electrical circuits to pre
vent accidental start‐up.
Never attempt to alter the length or re
pair any power cable with a splice. The
pump motor and cable must be com
pletely waterproof. Injury or death may
result from alterations.
All electrical connections must be in ac
cordance with The National Electric
Code and all local codes. If there is a
conflict between the instructions pro
vided and N.E.C. Specifications, N.E.C.
Specifications shall take precedence.
All electrical equipment supplied with
this pump was in conformance with
N.E.C. requirements in effect on the
date of manufacture. Failure to follow
applicable specifications, or substitu
tion of electrical parts not supplied or
approved by the manufacturer, can re
sult in severe injury or death and void
warranty.
After the pump has been installed, make
certain that the pump and all piping or
hose connections are secure before op
eration.
Approach the pump cautiously after it
has been running. Although the motor is
cooled by the liquid being pumped, nor
mal operating temperatures can be high
enough to cause burns. The tempera
ture will be especially high if operated
against a closed discharge valve. Never
operate against a closed discharge
valve for long periods of time.
Do not attempt to lift the pump by the
motor power cable or the piping. Attach
proper lifting equipment to the lifting
device fitted to the pump. If chains or
cable are wrapped around the pump to
lift it, make certain that they are posi
tioned so as not to damage the pump,
and so that the load will be balanced.
Obtain the services of a qualified elec
trician to troubleshoot, test and/or ser
vice the electrical components of this
pump.

MR-04319 S SERIES PUMPS
TROUBLESHOOTING PAGE B - 1
TROUBLESHOOTING - SECTION B
Review all SAFETY information in Section A.
The following precautions should be
taken before attempting to service the
pump; otherwise, injury or death could
result.
1. Familiarize yourself with this man
ual and with all other literature
shipped with the pump.
2. Lock out incoming power to the
pump or control box 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 discharge valve (if
used).
The electrical power used to operate
this pump is high enough to cause inju
ry or death. Obtain the services of a qu
alified electrician to troubleshoot, test
and/or service the electrical compo
nents of this pump.
NOTE
Many of the probable remedies listed below re
quire use of electrical test instruments; for specific
procedures, see ELECTRICAL TESTING following
the chart.
Table 1. Trouble Shooting Chart
TROUBLE POSSIBLE CAUSE PROBABLE REMEDY
PUMP FAILS TO START,
OVERLOAD UNIT NOT
TRIPPED
(MANUAL MODE)
(AUTOMATIC MODE)
Power source incompatible with con
trol box.
No voltage at line side of circuit break
er.
Open circuit in motor windings or
power cable.
Defective motor power cable.
Motor defective.
Liquid level device or control circuits
improperly connected to main control
box.
Level sensing device(s) improperly
positioned.
Level sensing device(s) fouled with
mud or foreign material.
Correct power source.
Check power source for blown fuse,
open overload unit, broken lead, or
loose connection.
Check continuity.
Replace cable.
Check for and replace defective unit.
Check wiring diagrams; correct or
tighten connections.
Position device(s) at proper level.
Clean sensing device(s).

S SERIES PUMPS MR-04319
TROUBLESHOOTINGPAGE B - 2
Table 1. Trouble Shooting Chart (cont.)
TROUBLE POSSIBLE CAUSE PROBABLE REMEDY
(AUTOMATIC MODE)
(CONT'D.)
Float type sensing device(s) tangled
or obstructed.
Defective liquid level sensing de
vice(s) or control panel.
Check installation for free move
ment of float.
Repair or replace defective unit(s).
OVERLOAD UNIT TRIPS Low or high voltage, or excessive
voltage drop between pump and
control box.
Defective insulation in motor wind
ings or power cable; defective wind
ings.
Impeller jammed due to debris or
insufficient clearance.
Bearing(s) frozen.
Measure voltage at control box.
Check that wiring is correct type,
size, and length. (See Field Wiring
Connections, Section B).
Check insulation resistance; check
continuity.
Disassemble pump and check im
peller.
Disassemble pump and check
bearing(s).
MOTOR RUNS, BUT
PUMP FAILS TO
DELIVER RATED
DISCHARGE
Discharge head too high.
Low or incorrect voltage.
Discharge throttling valve partially
closed; check valve is installed im
properly.
Discharge line clogged or re
stricted; hose kinked.
Liquid being pumped too thick.
Strainer screen or impeller clogged.
Insufficient liquid in sump or tank.
Worn impeller vanes; excessive im
peller clearance.
Pump running backwards.
Reduce discharge head, or install
staging adaptor and additional
pump.
Measure control box voltage, both
when pump is running and when
shut‐off.
Open discharge valve fully; check
piping installation.
Check discharge lines; straighten
hose.
Dilute liquid by heating if possible.
Clear clog(s). Stop pump; back flow
may flush away debris.
Stop pump until liquid level rises.
Check impeller and clearance. See
PUMP END DISASSEMBLY.
Check direction of rotation and cor
rect by interchanging any two motor
leads at control box. (See Pump
Rotation, Section C).

MR-04319 S SERIES PUMPS
TROUBLESHOOTING PAGE B - 3
Table 1. Trouble Shooting Chart (cont.)
TROUBLE POSSIBLE CAUSE PROBABLE REMEDY
PUMP RUNS WITH
EXCESSIVE NOISE OR
VIBRATION
Pumping entrained air.
Damaged or unbalanced impeller.
Discharge piping not properly sup
ported.
Impeller jammed or loose.
Motor shaft or bearings defective.
Pump cavitation.
Check liquid level in sump; check
position of pump and liquid level
sensing device(s).
Replace impeller.
Check piping installation.
Check impeller.
Disassemble pump and check mo
tor and bearings.
Reduce discharge head, or restrict
flow on low head applications.
ELECTRICAL TESTING
If you suspect that pump malfunctions are caused
by defects in the motor, power cable or control box,
perform the following checks to help isolate the de
fective part.
Obtain the services of a qualified elec
trician to troubleshoot, test and/or ser
vice the electrical components of this
pump.
Be certain to refer to the wiring diagram(s)
in the Installation Section of this manual be
fore reconnecting any electrical compo
nents which have been disconnected.
Test Equipment
A volt/amp/ohmmeter and megohmeter of ade
quate range and quality will be required to conduct
the following electrical tests. The suggested equip
ment indicated below is commercially available, or
an equivalent substitute may be used.
Equipment Use
Ammeter To check AC Voltage
and current (amperage)
Ohmeter To measure resistance
(ohms) to ground
Voltage Imbalance
Each phase of the incoming three‐phase power
must be balanced with the other two as accurately
as a commercial voltmeter will read. If the phases
are balanced, check out the motor as described
below. If the phases are out of balance, contact
your power company and request that they correct
the condition.
a. Use a voltmeter, amprobe, or equivalent me
ter to read the voltage across terminals 1 &
2, 2 & 3, and 1 & 3 in the control box. All three
measured voltages must be the same, as
accurately as the meter will read. If possible,
measure the voltage with the pump off, with
the pump running but out of the water, and
with the pump running in the water at full
load. All the measured voltages at each con
dition must be the same.
b. Use an amprobe or equivalent meter to
measure the current draw of each phase
while the pump is running at full load and at
no load. All three amperage readings must

S SERIES PUMPS MR-04319
TROUBLESHOOTINGPAGE B - 4
be the same at each condition, as accurate
ly as the meter will read. Nominal amperage
values are listed in Table 1, but these apply
only when the actual voltage at the site is the
nominal voltage listed.
c. If the voltages are balanced with the pump
off, but are unbalanced when the pump is
running, a thorough check of the power
source, all interconnecting cables, and the
pump motor is required to isolate the defect.
Motor And Motor Power Cable Continuity
To check continuity, zero‐balance the ohmmeter
set at the RX1 scale, and test as follows:
a Disconnect the motor power cable leads
from the control box and connect the test
leads to any two of the three power cable
leads (not to the green ground lead or yellow
ground check lead). If there is a high resis
tance reading on the ohmmeter, there is an
open or broken circuit caused by a break in
the power cable or motor windings, or by a
bad connection between the motor and the
power cable. Switch one test lead to the
third power lead, and test again.
b. If an open or broken circuit is indicated,
check the power cable for obvious damage,
and replace as necessary (see MAINTE
NANCE AND REPAIR). If there is no appar
ent damage to the motor cable, remove the
terminal housing (see MAINTENANCE
AND REPAIR) and check the continuity of
each power cable lead at the terminal posts.
NOTE
When shipped from the factory, the connections be
tween the power cable leads and the terminal posts
were encapsulated in heat shrink tubing and
bonded to the terminal plate to provide a water tight
seal. In service, these connections may have been
potted by the pump operator. Do not cut the tubing
or potting away unless absolutely necessary.
Check the continuity of each lead from the motor
side of the terminal plate. If the continuity is good,
there is no need to remove the tubing or potting ma
terial. If there is no continuity through the lead, re
move the tubing or potting from only that terminal,
and check for a loose connection. Be sure to re
place the tubing or potting and allow adequate dry
ing time before putting the pump back into service.
(See Power Cable Reassembly, Section E).
c. If an open circuit still exists after each lead
(terminal) has been tested and tightened,
then the entire motor power cable must be
replaced. Splicing or other means of repair
are not recommended.
d. If no break is found in the power cable,
check the motor leads for continuity. If the
test reading indicates an open or broken cir
cuit, there is an open circuit in the motor.
NOTE
It is recommended that a pump with a defective mo
tor be returned to Gorman‐Rupp, or to one of the
Gorman‐Rupp authorized Submersible Repair
Centers.
Insulation Resistance
To check insulation, zero‐balance the ohmmeter
set at the RX100K scale, and test as follows:
a. Disconnect the motor power cable leads
from the control box. Connect one test lead
to the power cable green ground lead, and
touch the other test lead to each of the three
power leads in turn.
b. The reading obtained will indicate resis
tance values in both the power cable and the
motor windings. If the resistance reading is
infinity (1), the insulation is in good condi
tion. If the reading is between infinity (1)
and 1 megohm, the insulation is acceptable
but should be rechecked periodically. If the
reading is less than 1 megohm, the insula
tion should be checked more closely; a
reading of zero indicates that the power
cable or the motor is grounded.
c. To determine whether the power cable or
the motor is grounded, remove the terminal
housing (see MAINTENANCE AND RE
PAIR), disconnect the motor leads from the
motor terminals, and test the power cable
leads and motor leads separately.

MR-04319 S SERIES PUMPS
PAGE C - 1MAINTENANCE AND REPAIR
PUMP MAINTENANCE AND REPAIR - SECTION C
GENERAL INFORMATION
Review all SAFETY information in Section A.
Do not attempt to service the pump as
sembly unless all power to the motor
has been shut off at the control box;
otherwise, injury or death could result.
Use a lifting device with sufficient ca
pacity. If slings or chains are used to
move the pump or components, make
sure that the load is balanced; other
wise serious personal injury or death
could result.
The maintenance and repair instructions in this
manual are keyed to the sectional views, Figures
C-1 and C-2, and the corresponding parts identi
fication lists. Refer to the separate Parts List Manu
al for replacement parts.
Select a suitable location, preferably indoors, to
perform required maintenance. All work must be
performed by qualified personnel.
All repairs to the pump motor must be per
formed by a Gorman‐Rupp authorized
Submersible repair facility or the factory.
Any repairs to the motor assembly per
formed by the customer or an unautho
rized repair facility negates the warranty.
This Maintenance and Repair Manual provides
troubleshooting and maintenance instructions re
quired to properly diagnose operational problems,
and to service the pump components. Pump motor
maintenance may be performed only by a Gor
man‐Rupp authorized Submersible repair facility,
or the factory. Otherwise, the pump warranty will be
negated, and damage to the pump, and injury or
death to personnel can result. Contact the factory
for the authorized repair facility closest to you.
Check TROUBLESHOOTING, Section B to deter
mine causes and remedies of pump problems.
Disassemble the pump only as far as required.
Lifting
Use lifting equipment with a capacity of at least
five times the weight of the pump, including the
weight of any options or customer‐installed acces
sories. Contact the factory or refer to the pump
Specification Data Sheet for the weight of your
pump. Discharge hose or piping must be removed
before attempting to lift the pump.

S SERIES PUMPS MR-04319
MAINTENANCE AND REPAIRPAGE C - 2
SECTION DRAWING
Figure C-1. Typical S8D Series Pump Assembly

ITEM
NO. PART NAME
ITEM
NO. PART NAME
MR-04319 S SERIES PUMPS
PAGE C - 3MAINTENANCE AND REPAIR
Typical S8D Series Pump Assembly
Parts Identification List
Refer to the separate Parts List Manual for serviceable parts, part numbers and quantities.
1 1ST STAGE DIFFUSER
2 2ND STAGE DIFFUSER
3 1ST STAGE IMPELLER
4 2ND STAGE IMPELLER
5 LOWER SEAL ASSEMBLY
6 UPPER SEAL ASSEMBLY
7 VANE PLATE
8 HEX HEAD CAPSCREW
9 STUD
10 LOCKWASHER
11 HEX NUT
12 DIFFUSER GASKET
13 SEAL PLATE
14 SEAL PLATE O‐RING
15 PIPE PLUG
16 MOISTURE DETECTOR
17 LOWER BALL BEARING
18 INTERMEDIATE
19 MOTOR HOUSING O‐RING
20 MOTOR HOUSING O‐RING
21 STATOR
22 ROTOR/SHAFT ASSEMBLY
23 MOISTURE PROBE WIRE
24 TERMINAL
25 PIPE PLUG
26 UPPER BALL BEARING
27 MOTOR HOUSING
28 FLANGE GASKET
29 DISCHARGE FLANGE
30 STUD
31 HEX NUT
32 FILL TUBE ASSEMBLY
33 EYE BOLT
34 RETAINING RING
35 PIPE CAP
36 PRESSURE RELIEF VALVE
37 STREET TEE ASSEMBLY
38 HEAVY PIPE NIPPLE
39 TERMINAL HOUSING AND
CABLE ASSEMBLY
40 STUD
41 DEFORM HEX NUT
42 NAME PLATE
43 DRIVE SCREW
44 KEY
45 HEX HEAD CAPSCREW
46 LOCKWASHER
47 HEX NUT
48 BEARING CAP
49 BEARING CAP GASKET
50 HEX HEAD CAPSCREW
51 LOCKWASHER
52 PIPE PLUG
53 WEAR RING
54 PIPE PLUG
55 INTERMEDIATE GASKET
56 SOCKET HEAD CAPSCREW
57 LOCK NUT
58 LOCKWASHER
59 WEAR RING
60 DIFFUSER GASKET
61 HEX HEAD CAPSCREW
62 LOCKWASHER
63 HEX NUT
64 SOCKET HEAD CAPSCREW
65 STRAINER SCREEN
66 BASE ASSEMBLY
67 HEX HEAD CAPSCREW
68 HEX HEAD CAPSCREW
69 LOCKWASHER
70 SUCTION HEAD
71 WEAR RING
72 WEAR RING
73 IMPELLER WASHER
74 IMPELLER NUT
75 IMPELLER KEY
76 HEX HEAD CAPSCREW
77 LOCKWASHER
78 SUCTION HEAD GASKET
79 OIL SEAL
80 MALE TAB

S SERIES PUMPS MR-04319
MAINTENANCE AND REPAIRPAGE C - 4
SECTION DRAWING
Figure C-2. Terminal Housing And Cable Assembly

MR-04319 S SERIES PUMPS
PAGE C - 5MAINTENANCE AND REPAIR
Terminal Housing And Cable Assembly
Parts Identification List
Refer to the separate Parts List Manual for serviceable parts, part numbers and quantities.
ITEM
NO. PART NAME
1 #2/0 POWER CABLE - 50 FT.
2 CABLE GRIP
3 STUD
4 HEX NUT
5 TERMINAL GLAND
6 GLAND BUSHING
7 TERMINAL WASHER
8 TERMINAL HOUSING
9 #2/0 WIRE TERMINAL
10 ROUND HEAD MACHINE SCREW
11 T‐TYPE LOCKWASHER
12 HEAT‐SHRINK TUBE
13 ALLEN HEAD SETSCREW
14 TERMINAL COLLAR
15 DYNA‐SEAL WASHER
16 TERMINAL PLATE ASSEMBLY
17 DYNA‐SEAL WASHER
18 TERMINAL POST
19 HEX HEAD CAPSCREW
20 LOCKWASHER
21 HEX NUT
22 HEAT‐SHRINK TUBE
23 ALLEN HEAD SETSCREW
24 TERMINAL POST
25 DYNA‐SEAL WASHER
26 TERMINAL COLLAR
27 ALLEN HEAD SETSCREW
28 HEAT‐SHRINK TUBE
29 GLAND BUSHING
30 INFORMATION PLATE
31 DRIVE SCREW
32 TERMINAL GLAND
33 STUD
34 HEX NUT
35 CABLE GRIP
36 #14 CONTROL CABLE-50 FT.

S SERIES PUMPS MR-04319
MAINTENANCE AND REPAIRPAGE C - 6
PUMP END DISASSEMBLY
References are to Figure C-1 and Figure C-2.
Review all SAFETY information in Section A.
Follow the instructions on all tags, label and de
cals attached to the pump.
The following maintenance and repair instructions
are keyed to the Pump Model sectional view (Fig
ure C-1) and the Terminal Housing sectional
views (Figure C-2), and the accompanying parts
lists. Refer to the Parts List manual for the part num
ber and quantity required.
Before attempting to service the pump or control,
terminate the power supply to the control box.
Close the discharge throttling valve, if so
equipped.
The pump motor is equipped with a thermal over
load protector which automatically shuts the motor
down when the operating temperature exceeds
design limits. After the motor cools down, it will au
tomatically restart. Always terminate power to the
pump and control box before investigating pump
or control box problems.
The pump motor is thermally protected
and subject to automatic restart. Always
terminate power to the pump and con
trol box. Before performing service
functions.
The electrical power used to operate
this pump is high enough to cause inju
ry or death. Make certain that the control
handle on the control box is in the OFF
position and locked out, or that the pow
er supply to the control box has been
otherwise cut off and locked out, before
attempting to open or service the pump
assembly. Tag electrical circuits to pre
vent accidental start‐up.
Use the lifting device fitted on the pump to remove
the pump from the wet well or sump, and move it to
a location where the discharge line can be re
moved. It is not necessary to disconnect a flexible
discharge hose before removing the pump. If rigid
discharge piping is used, disconnect the piping
before attempting to move the pump.
Do not attempt to lift the pump by the
motor power cable or the piping. Attach
proper lifting equipment to the lifting
device fitted to the pump. If chains or
cable are wrapped around the pump to
lift it, make certain that they are posi
tioned so as not to damage the pump,
and so that the load will be balanced.
Select a suitable location, preferably indoors, to
perform the degree of maintenance required. If the
motor housing is to be opened, the work must be
done in a clean, well‐equipped shop. All mainte
nance functions must be done by qualified person
nel.
Check the chart in TROUBLESHOOTING, Section
B of this manual, to determine the nature of the
pump problem. If the problem is mechanical in na
ture, such as worn pump parts, seal replacement,
lubrication, etc., refer to PUMP END DISASSEM
BLY for instructions.
If the problem is electrical, complete disassembly
may not be required. Refer to Electrical Testing in
TROUBLESHOOTING, Section B, and have a
qualified electrician check the control box, cable
and terminal housing. If the problem is determined
to be in the motor, proceed with PUMP END DIS
ASSEMBLY, followed by MOTOR DISASSEMBLY.
Otherwise, see Terminal Housing And Power Ca
ble Disassembly.
Carefully inspect any O‐rings or gaskets before re
moval and cleaning to determine if a proper seal
and compression existed prior to disassembly. If
sealing was faulty or questionable, the cause must

MR-04319 S SERIES PUMPS
PAGE C - 7MAINTENANCE AND REPAIR
be determined and corrected before reassembly.
All gaskets and most O‐rings must be replaced if
disturbed. Repair gaskets and O‐rings are listed in
the Parts List manual.
Strainer Removal
(Figure C-1)
To remove the strainer screen (65), raise the pump
slightly, or lay it on its side and disengage the hard
ware (67) securing the base plate (66) and strainer
assembly to the 1st stage diffuser (1). Remove the
base plate and strainer screen. If the impeller (3) is
clogged, the debris can usually be removed with
out further disassembly.
Draining Oil From Seal And Motor Cavity
(Figure C-1)
If any further disassembly is to be performed on the
pump, the seal and motor oil cavities must be
drained.
Let the pump cool before removing the
seal or motor cavity drain plugs. Pressure
built up within a hot pump could cause the
oil to spray out when the plug is removed.
Remove the plugs slowly and permit pres
sure to vent to atmosphere.
Lay the pump on its side with the pipe plugs (15
and 54) facing up. Clean any dirt from around the
plugs. Remove the seal cavity drain plug (54), and
install a short 3/8‐inch NPT nipple in the hole. Tip
the pump and drain the seal oil into a clean con
tainer. Inspect the oil for water, dirt, or cloudy condi
tion which could indicate lower seal failure or poor
gasket seal.
If motor problems are suspected, remove the mo
tor cavity drain plug (15) and use the short nipple to
drain the oil into a clean container. Inspect the oil
for a dark color which could indicate motor over
heating, dirt or water contamination. The presence
of dirt or water could indicate a breakdown in the
waterproof integrity of the motor cavity, probably
due to poor gaskets or seals.
Positioning Pump For Disassembly
(Figure C-1)
It is recommended that the pump be positioned
upside‐down during disassembly. To hold the
pump in the inverted position, rest the pump se
curely on blocks. Two brackets with lifting eyes
may be fabricated for this purpose as shown in Fig
ure C-3. Be careful not to damage the terminal
housing and cable assembly (31) while in this posi
tion. Use adequate equipment and personnel to
safely handle the pump until it is secured. If invert
ing the pump is not practical, lay the pump on its
side and secure it to prevent rolling.
2.38”
1.5”
1.5” DIA.
DRILL
THROUGH
BOTH
SIDES
1.0” UNC THREAD X 2.5” LONG
SHOULDER PATTERN WELDLESS
DROP‐FORGED EYE BOLT, NUTS
AND FLAT WASHERS
MAKE FROM 0.50”
FLAME CUT PLATE
1.06” DIA.
DRILL THROUGH
TYP. ALL
POINTS
4.5”
5.5”
4.75” 3.0”
.38”
1.25”
Figure C-3. Lifting Brackets With
Eyes
Remove two of the capscrews, lockwashers and
hex nuts (45, 46 and 47) from opposite sides of the
motor housing. Secure the brackets to the pump
using two 1-1/4-16 UNC by 7-inch long caps
crews (not supplied) and the lockwashers and
nuts (46 and 47).
Remove the lifting eyes (33) and pressure relief
valve and piping (35, 36, 37 and 38). Attach chains
and a spreader bar to the eyes in the lifting brack
ets.
Use caution not to damage the terminal
housing and cable assembly when invert

S SERIES PUMPS MR-04319
MAINTENANCE AND REPAIRPAGE C - 8
ing the pump for disassembly. Use wood
blocks to support and level the pump while
performing maintenance, and leave the lift
ing device attached if possible.
Use a lifting device of suitable capacity to raise the
pump just high enough to be rotated to the in
verted position. Rest the pump securely on blocks
positioned across the discharge flange. Be careful
not to damage the terminal housing (39) or cable
while in this position.
Suction Head And Wear Ring Removal
(Figure C-1)
Remove the hardware (68 and 69) securing the
suction head (70) to the first stage diffuser (1). Re
move the suction head, and remove and discard
the suction head gasket (78).
Inspect the wear ring (71) for excessive wear or
scoring. If replacement is required,use a small bit
to drill two holes horizontally through the wear ring,
180_apart. Use a chisel to complete the cuts
through the wear ring, and remove it from the suc
tion head. Be careful not to damage the suction
head bore.
Use caution not to damage the suction
head when removing the wear ring.
First Stage Impeller Removal
(Figure C-1)
Immobilize the first stage impeller (3) by wedging a
steel rod between the vanes. Remove the impeller
nut and washer (73 and 74). Install two 3/8-16
UNC by 2-inch long capscrews in the tapped
holes in the impeller, and use a suitable puller to re
move the impeller from the shaft.
First Stage Diffuser And Vane Plate Removal
(Figure C-1)
Disengage the hardware (61, 62 and 63) and sepa
rate the first stage diffuser (1), vane plate (7), and
gasket (60) from the second stage diffuser (2).
Remove the socket head capscrews (64) and sep
arate the vane plate from the first stage diffuser.
Inspect the wear ring (72) for excessive wear or
scoring. If replacement is required, remove the
hardware (76 and 77), and use an arbor (or hydrau
lic) press to remove the wear ring.
If no further disassembly is required, proceed to
the appropriate areas in PUMP END REASSEMB
LY.
Second Stage Diffuser and Wear Ring Removal
(Figure C-1)
Disengage the hardware (8, 10 and 11) and sepa
rate the second stage diffuser (2) and gaskets (12
and 55) from the seal plate (13) and intermediate
(18).
Inspect the wear ring (59) for excessive wear or
scoring. If replacement is required, use a small bit
to drill two holes horizontally through the wear ring,
180_apart. Use a chisel to complete the cuts
through the wear ring, and remove it from the sec
ond stage diffuser. Be careful not to damage the
diffuser bore.
Second Stage Impeller Removal
(Figure C-1)
A tool for removing the lock nut (57) may be fabri
cated as shown in Figure C-4.
2 PIECES OF 0.25” SQUARE X 1.5” LONG KEYSTOCK
- POSITION 180_APART AND WELD
5.0”0.5”
MAKE FROM STANDARD 2.75” O.D. 16 GA. TUBING
Figure C-4. Impeller Locknut Tool
Wedge a steel rod between the vanes of the impel
ler (1) and one of the studs (9) to prevent shaft rota
tion. Straighten the taps on the impeller lockwash
er (58), and position the locknut removal tool over

MR-04319 S SERIES PUMPS
PAGE C - 9MAINTENANCE AND REPAIR
the shaft so the keystock engages the slots in the
locknut. Use a pipe wrench to turn the tool and re
move the locknut and washer.
Remove the rod from the impeller vanes, and install
two 3/8-16 UNC by 2-inch long capscrews in the
tapped holes in the impeller, and use a suitable
puller to remove the impeller from the shaft. Use
caution when removing the impeller; tension on
the seal spring will be released. Retain the impeller
key (75).
Lower Seal Removal
(Figures C-1 and C-5)
Carefully remove the seal spring. Lubricate the ro
tor shaft (22) and work oil under the bellows as
sembly. Slide the hooked ends of two stiff wires
along the shaft and pull the rotating portion of the
seal from the shaft.
To remove the stationary portion of the seal, re
move the socket head capscrews (56), and slide
the seal plate (13) from the shaft. Remove and dis
card the seal plate O‐ring (14). Place a clean cloth
on a flat surface and place the seal plate on the
cloth with the impeller side down. Use a drift pin or
screwdriver to press on alternate sides of the sta
tionary seat until the stationary element and seat
are removed.
NOTE
Use caution not to damage the moisture detector
(16) after the seal plate is removed.
If no further disassembly is required, proceed to
the appropriate areas in PUMP END REASSEMB
LY.
Upper Seal Removal
(Figures C-1 and C-5)
Unless cracked or otherwise worn, it is not neces
sary to remove the intermediate (18) for access to
the upper seal assembly (6).
If the intermediate must be removed, see
the procedure under Motor Disassembly
in this section. Do not attempt to loosen
the hardware (45, 46, 47, 50 and 51) secur
ing the intermediate or bearing cap (48)
before referring to this section; otherwise,
the rotor shaft and bearings could be dam
aged.
Remove the seal retaining ring (34) using snap ring
pliers. Use caution when removing the retaining
ring; tension on the seal spring will be released.
Remove the spring retainer and seal spring.
Lubricate the rotor shaft (22) and work oil under the
bellows. Position a screwdriver or other suitable
device on each side of the bellows retaining flange,
and pry the bellows upward until the rotating por
tion is off the shaft. Slide the hooked ends of two
stiff wires along the shaft and under the stationary
seal seat. Hook the back side of the seat and pull it
from the intermediate bore.
If no further disassembly is required, proceed to
the appropriate areas in PUMP END REASSEMB
LY.
NOTE
Do not disassemble the motor unless it is neces
sary and a clean, well‐equipped shop is available. If
the motor housing components are to be serviced,
see MOTOR DISASSEMBLY in this section. Do not
reassemble the end components at this time.
PUMP END REASSEMBLY
NOTE
Reuse of old O‐rings, gaskets, or shaft seal parts
will result in premature leakage or reduced pump
performance. It is strongly recommended that new
gaskets and shaft seal assemblies be used during
reassembly (see the parts lists for numbers).
Cleaning And Inspection Of Pump Parts
(Figure C-1)
With the pump inverted, stuff a clean tissue into the
stationary seal seat bore of the intermediate (18) or
wrap a small rag around the shaft to prevent for
eign material from entering the motor cavity.
Carefully inspect any O‐rings or gaskets before re
moval and cleaning to determine if a proper seal

S SERIES PUMPS MR-04319
MAINTENANCE AND REPAIRPAGE C - 10
and compression existed prior to disassembly. If
sealing was faulty or questionable, the cause must
be determined and corrected before reassembly.
Replace any parts as required.
Thoroughly clean all reuseable parts with a soft
cloth soaked in cleaning solvent. Remove all O‐
rings and gaskets, and clean the sealing surfaces
of dirt or gasket material. Be careful not to scratch
gasket surfaces. Use a clean cloth lightly damp
ened with solvent to clean the motor housing,suc
tion head, diffuser and seal plate. Do not allow the
solvent to enter the motor.
Most cleaning solvents are toxic and
flammable. Use them only in a well ven
tilated area free from excessive heat,
sparks, and flame. Read and follow all
precautions printed on solvent contain
ers.
Inspect the rotor shaft (22) for damaged threads,
scoring, or nicks. Remove nicks and burrs with a
fine file or hand honing stone to restore original
contours. If the shaft is bent or severely damaged,
the rotor and shaft must be replaced as an assem
bly (see MOTOR DISASSEMBLY).
Neither of the shaft seal assemblies (5 or 6) should
be reused because wear patterns on the finished
faces cannot be realigned during reassembly. This
could result in premature failure. If necessary to re
use an old seal in an emergency, carefully wash
all metallic parts in fresh cleaning solvent and allow
to dry thoroughly.
Handle the seal parts with extreme care to prevent
damage. Be careful not to contaminate the preci
sion finished faces; even fingerprints on the faces
can shorten seal life. If necessary, clean the faces
with a non‐oil based solvent and a clean, lint‐free
tissue. Wipe lightly in a circular pattern to avoid
scratching the faces.
Inspect the seal components for wear, scoring,
grooves, and other damage that might cause leak
age. If any components are worn, replace the com
plete seal; never mix old and new seal parts.
Install the shaft seals as illustrated in Figure C-5.