GORMAN-RUPP S Series Operating instructions

PUBLICATION NUMBER MR-04152
December 19, 1994
Rev. E 05‐15‐12
THE GORMAN‐RUPP COMPANY DMANSFIELD, OHIO
www.grpumps.com
GORMAN‐RUPP OF CANADA LIMITED DST. THOMAS, ONTARIO, CANADA Printed in U.S.A.
e1995 The Gorman‐Rupp Company
S SERIES PUMPS
S4C, S4D and S4H
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-04152 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.......
TERMINAL HOUSING AND CABLE ASSEMBLY PAGE C - 6...................................
TERMINAL HOUSING AND CABLE ASSEMBLY PARTS IDENTIFICATION LIST PAGE C - 7.......
PUMP END DISASSEMBLY PAGE C - 8....................................................
PUMP END REASSEMBLY PAGE C - 10....................................................
MOTOR DISASSEMBLY PAGE C - 13......................................................
MOTOR REASSEMBLY PAGE C - 17.......................................................

MR-04152S SERIES PUMPS
PAGE I - 2 INTRODUCTION
FINAL ASSEMBLY PAGE C - 24...........................................................
VACUUM TESTING5 PAGE C - 24.........................................................
LUBRICATION PAGE C - 25...............................................................
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-04152 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

S SERIES PUMPS MR-04152
PAGE A-2 SAFETY
coming power matches the voltage and
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.

TROUBLE POSSIBLE CAUSE PROBABLE REMEDY
PUMP FAILS TO
START, OVER
LOAD UNIT NOT
TRIPPED (MANU
AL MODE)
(AUTOMATIC
MODE)
MR-04152 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.
Power source incompatible with control Correct power source.
box.
No voltage at line side of circuit beaker. Check power source for blown fuse,
open overload unit, broken lead, or
loose connection.
Open circuit in motor windings or power Check continuity.
cable.
Defective motor power cable. Replace cable.
Motor defective. Check for and replace defective unit.
Liquid level device or control circuits im‐ Check wiring diagrams; correct or
properly connected to main control box. tighten connections.
Level sensing device(s) improperly Position device(s) at proper level.
positioned.
Level sensing device(s) fouled with Clean sensing device(s).
mud or foreign material.

TROUBLE POSSIBLE CAUSE PROBABLE REMEDY
OVERLOAD UNIT
TRIPS
MOTOR RUNS,
BUT PUMP FAILS
TO DELIVER
RATED DIS
CHARGE
(AUTOMATIC
MODE )
(CONT'D.)
S SERIES PUMPS MR-04152
TROUBLESHOOTINGPAGE B - 2
Float type sensing device(s) tangled or Check installation for free movement
obstructed. of float.
Defective liquid level sensing device(s) Repair or replace defective unit(s).
or control panel.
Low or high voltage, or excessive volt‐ Measure voltage at control box.
age drop between pump and control Check that wiring is correct type,
box. size, and length. (See Field
Wiring Connections,Section B).
Defective insulation in motor windings Check insulation resistance; check
or power cable; defective windings. continuity.
Impeller jammed due to debris or insuf‐ Disassemble pump and check impel‐
ficient clearance. ler.
Bearing(s) frozen. Disassemble pump and check bear‐
ing(s).
Discharge head too high. Reduce discharge head, or install
staging adaptor and additional pump.
Low or incorrect voltage. Measure control box voltage, both
when pump is running and
when shut‐off.
Discharge throttling valve partially Open discharge valve fully; check pip‐
closed; check valve is installed improp‐ ing installation.
erly.
Discharge line clogged or restricted; Check discharge lines; straighten
hose kinked. hose.
Liquid being pumped too thick. Dilute liquid by heating if possible.
Strainer screen or impeller clogged. Clear clog(s). Stop pump; back flow
may flush away debris.
Insufficient liquid in sump or tank. Stop pump until liquid level rises.
Worn impeller vanes; excessive impeller Check impeller and clearance. See
clearance. PUMP END REASSEMBLY.
Pump running backwards. Check direction of rotation and cor‐
rect by interchanging any two mo‐
tor leads at control box. (See Pump
Rotation, Section C).

PUMP RUNS WITH
EXCESSIVE NOISE
OR VIBRATION
TROUBLE POSSIBLE CAUSE PROBABLE REMEDY
MR-04152 S SERIES PUMPS
TROUBLESHOOTING PAGE B - 3
Pumping entrained air. Check liquid level in sump; check
position of pump and liquid level
sensing device(s).
Damaged or unbalanced impeller. Replace impeller.
Discharge piping not properly support‐ Check piping installation.
ed.
Impeller jammed or loose. Check impeller.
Motor shaft or bearings defective. Disassemble pump and check motor
and bearings.
Pump cavitation. 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

S SERIES PUMPS MR-04152
TROUBLESHOOTINGPAGE B - 4
while the pump is running at full load and at
no load. All three amperage readings must
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-04152 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, C-2 or C-3, and the corresponding parts
identification lists. Refer to the separate Parts List
Manual 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. The approximate maximum weight for this
group of pumps is 206 lbs. (93,4 kg.). Discharge
hose or piping must be removed before attempt
ing to lift the pump.

S SERIES PUMPS MR-04152
MAINTENANCE AND REPAIRPAGE C - 2
SECTION DRAWING
S4H SERIES ONLY
Figure C-1. Typical S4C, S4D And S4H Series Pump Assembly

ITEM
NO. PART NAME
ITEM
NO. PART NAME
MR-04152 S SERIES PUMPS
PAGE C - 3MAINTENANCE AND REPAIR
Typical S4C, S4D And S4H Series Pump Assembly
Parts Identification List
Refer to the separate Parts List Manual for serviceable parts, part numbers and quantities.
1 DIFFUSER
2 IMPELLER
3 LOWER SEAL ASSY
4 UPPER SEAL ASSY
5 FLAT HEAD MACHINE SCREW
6 SOCKET HD CAPSCREW
7 SEAL PLATE
8 INTERMEDIATE GASKET
9 INTERMEDIATE GASKET
10 MOTOR HOUSING
11 LOWER BALL BEARING
12 BEARING SNAP RING
13 PUMP CASING
14 MOTOR HOUSING O‐RING
15 PUMP CASING O‐RING
16 UPPER MOTOR HOUSING
17 DISCHARGE FLANGE GASKET
18 DISCHARGE FLANGE
19 STUD
20 HEX NUT
21 SHAFT SLEEVE
22 IMPELLER ADJ SHIM SET
23 SEAL RETAINING RING
24 HOIST BAIL
25 BAIL BUSHING
26 HEX HD CAPSCREW
27 LOCKWASHER
28 FLAT WASHER
29 NAME PLATE
30 DRIVE SCREW
31 STUD
32 LOCKWASHER
33 HEX NUT
34 RED PIPE BUSHING
35 RELIEF VALVE ASSY
36 TERMINAL HOUSING/CABLE ASSY
37 CONNECTOR
38 HEAT SHRINK TUBE
39 WIRE MARKER KIT
40 BEARING SPRING WASHER
41 UPPER BALL BEARING
42 STATOR
43 ALLEN HD SETSCREW
44 PIPE PLUG
45 STUD
46 DEFORM LOCKNUT
47 ROTOR W/SHAFT
48 INTERMEDIATE O‐RING
49 MOTOR CAVITY DRAIN PLUG
50 SEAL CAVITY DRAIN/FILL PLUG
51 INTERMEDIATE
52 DIFFUSER O‐RING
53 SEAL PLATE GASKET
54 STUD
55 LOCKWASHER
56 HEX NUT
57 STRAINER ASSY
58 WEAR PLATE
59 HEX HD CAPSCREW
60 LOCKWASHER
61 FLAT WASHER
62 IMPELLER NUT
63 IMPELLER KEY
64 O‐RING (S4H's ONLY)
65 WEAR PLATE GASKET (S4H's ONLY)

S SERIES PUMPS MR-04152
MAINTENANCE AND REPAIRPAGE C - 4
SECTION DRAWING
Figure C-2. S4C,S4D And S4H Terminal Housing And Cable Assembly
Standard and SST‐Fitted Models

MR-04152 S SERIES PUMPS
PAGE C - 5MAINTENANCE AND REPAIR
Terminal Housing And Cable Assembly
Standard and SST‐Fitted Models
Parts Identification List
Refer to the separate Parts List Manual for serviceable parts, part numbers and quantities.
ITEM
NO. PART NAME
1 DYNA SEAL WASHER
2 UPPER TERMINAL PLATE GASKET
3 WIRE TERMINAL
4 HEX NUT
5 TERMINAL HOUSING
6 ROUND HEAD MACHINE SCREW
7 T TYPE LOCKWASHER
8 TERMINAL
9 TERMINAL
10 CABLE ASSEMBLY
11 CABLE GRIP
12 INFORMATION PLATE
13 DRIVE SCREW
14 HEAT SHRINK TUBE
15 HEX NUT
16 TERMINAL PLATE
17 LOWER TERMINAL PLATE GASKET
18 RTV SEALANT
19 TERMINAL
20 ROUND HEAD NYLOCK MACHINE SCREW

S SERIES PUMPS MR-04152
MAINTENANCE AND REPAIRPAGE C - 6
SECTION DRAWING
Figure C-3. Terminal Housing And Cable Assembly
All‐SST Models Only

MR-04152 S SERIES PUMPS
PAGE C - 7MAINTENANCE AND REPAIR
Terminal Housing And Cable Assembly
All‐SST Models Only
Parts Identification List
Refer to the separate Parts List Manual for serviceable parts, part numbers and quantities.
ITEM
NO. PART NAME
1 DYNA SEAL WASHER
2 UPPER TERMINAL PLATE GASKET
3 WIRE TERMINAL
4 HEX NUT
5 TERMINAL HOUSING
6 ROUND HEAD MACHINE SCREW
7 T TYPE LOCKWASHER
8 TERMINAL
9 TERMINAL
10 CABLE ASSEMBLY
11 TERMINAL CAP
12 INFORMATION PLATE
13 DRIVE SCREW
14 HEAT SHRINK TUBE
15 HEX NUT
16 TERMINAL PLATE
17 LOWER TERMINAL PLATE GASKET
18 RTV SEALANT
19 TERMINAL
20 ROUND HEAD NYLOCK MACHINE SCREW
21 STUD
22 HEX NUT
23 TERMINAL BUSHING
24 MOTOR PLATE
25 DRIVE SCREWS

S SERIES PUMPS MR-04152
MAINTENANCE AND REPAIRPAGE C - 8
PUMP END DISASSEMBLY
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 or C-3), and the accompany
ing parts lists. Refer to the Parts List manual for the
part number 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 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 hoisting bail to remove the pump from the
wet well or sump, and move it to a location where
the discharge line can be removed. It is not neces
sary 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
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.
PUMP END DISASSEMBLY
Strainer Removal
(Figure C-1)
To remove the strainer assembly (57), raise the
pump slightly, or lay it on its side and disengage
the hardware (59 and 60) securing the strainer to
the diffuser (1). If the impeller (2) is clogged, the de
bris can usually be removed without further disas
sembly.

MR-04152 S SERIES PUMPS
PAGE C - 9MAINTENANCE AND REPAIR
Draining Oil From Seal Cavity
(Figure C-1)
If any further disassembly is to be performed on the
pump, the seal oil cavity must be drained.
Let the pump cool before removing the
seal cavity drain plug. Pressure built up
within a hot pump could cause the oil to
spray out when the plug is removed. Re
move the plug slowly and permit pressure
to vent to atmosphere.
Lay the pump on its side with the pipe plugs (49
and 50) facing up. Clean any dirt from around the
plugs. Remove the seal cavity drain plug (50), and
install a short 1/4‐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.
Draining Oil From Motor Cavity
(Figure C-1)
If motor problems are suspected, remove the mo
tor cavity drain plug (49), and install a short nipple
in the hole. Tip the pump and drain the motor oil
into a clean container. Inspect the oil for dark color
which could indicate motor overheating, water or
dirt contamination. The presence of dirt or water
could indicate a breakdown in the waterproof in
tegrity 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. Be careful not to damage the ter
minal housing and cable assembly (36) while in
this position. Use adequate equipment and per
sonnel to safely handle the pump until it is secured.
If inverting the pump is not practical, lay the pump
on its side and secure it to prevent rolling.
Diffuser And Wear Plate Removal
(Figure C-1)
It is not necessary to remove the wear plate (58)
unless complete pump disassembly is required. To
remove the wear plate, disengage the hardware
(55 and 56) securing the wear plate and diffuser (1)
to the intermediate (51). Remove the wear plate
and diffuser. Remove and discard the O‐ring (52).
S4H Series Only - Remove and discard the O‐
rings (64) and the wear plate gasket (65).
Impeller Removal
(Figure C-1)
Wedge a piece of wood between the vanes of the
impeller (2) and the intermediate studs (54). Re
move the impeller nut (62) and washer (61).
Remove the wood and use a suitable puller to re
move the impeller from the shaft. Use caution when
removing the impeller; tension on the seal spring
will be released. Retain the impeller key (63).
NOTE
An alternate method of removing the impeller it to
pry the impeller off the shaft using two screwdrivers
against the back side of the impeller.
Remove the impeller adjusting shim set (22). For
ease of reassembly, tie and tag the shims or mea
sure and record their thickness.
Lower Seal Removal
(Figures C-1 and C-4)
Carefully remove the spring retainer and the seal
spring. Lubricate the rotor shaft (47) and work oil
under the bellows assembly. Use the hooked ends
of two stiff wires to hook the retainer and pull the
sleeve and rotating portion of the seal off the shaft.
Slide the retainer and bellows assembly off the
sleeve (21).
To remove the stationary portion of the seal, re
move the flat head machine screws (5) and sepa

S SERIES PUMPS MR-04152
MAINTENANCE AND REPAIRPAGE C - 10
rate the seal plate (7) from the intermediate (51).
Remove and discard the seal plate gasket (53).
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 stationary seat until the stationary ele
ment and seat are 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-4)
Unless cracked or otherwise worn, it is not neces
sary to remove the intermediate (51) for access to
the upper seal assembly (4).
Remove the seal retaining ring (23) 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 (47) and work oil under the
bellows. Use the hooked ends of two stiff wires to
hook the retainer and slide the rotating portion of
the seal off the shaft.
Slide the hooked ends of the two wires along the
shaft and under the stationary seal seat. Hook the
back side of the seat and pull it from the intermedi
ate 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 pump 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 (51) 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
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.
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 (47) 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 (3 or 4) 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