Gormann-Rupp Pumps AMT 3993-96 Assembly instructions

Specications Information and Repair Parts Manual 3993-96, 3993-Z6, 3994-96 & 4210-96
3993-254-00 1 3/2017
Please read and save this Repair Parts Manual. Read this manual and the General Operating Instructions carefully before attempting to assemble, install, operate
or maintain the product described. Protect yourself and others by observing all safety information. The Safety Instructions are contained in the General Operating
Instructions. Failure to comply with the safety instructions accompanying this product could result in personal injury and/or property damage! Retain instructions
for future reference. AMT reserves the right to discontinue any model or change specications at any time without incurring any obligation.
©2017 AMT Pump Company, A Subsidiary of The Gorman-Rupp Company, All Rights Reserved.
Periodic maintenance and inspection is required on all pumps to ensure proper operation. Unit must be clear of debris and sediment. Inspect for leaks and loose bolts. Failure to do so
voids warranty.
4-INCH TRASH PUMP
Refer to pump manual 1808-633-00 for General Operating and Safety Instructions.
SPECIFICATIONS
Suction inlet................................................................4” MNPT
Discharge outlet.........................................................4” MNPT
Engine
4210-96..............................................................Honda GX390
3993-96*............................................................B&S Vanguard
3994-96*.............................................................Honda GX390
3993-Z6*...................................................................Hatz 1B50
*E-Start Models
Basic construction...................Aluminum with cast iron volute,
impeller, wear plates and discharge manifold; silicon carbide
seal.
Battery........12 Volt, type No. 9A1, 32 amp hour (not supplied)
Battery tray*...............................................5” W x 7¾” L x 5” H
(*E-Start Models)
UNPACKING
Refer to Repair Parts Illustration and Repair Parts List to aid in
identifying parts. Unpack and separate all pump components
from container making sure all parts are accounted for.
Packages should contain:
1. Pump and engine completely assembled on wheel kit.
2. Battery tray (Ref. No. 43) and battery tray hardware (E-start
models only).
3. 4” NPT Nipple Pack and Strainer.
ASSEMBLY
(Refer to Figure 2)
1. Remove pump from packaging.
2. Stand pump carefully on pump end. Reposition handle
(Ref. No. 42) (as shown in Figure 2) facing outwards by
removing and replacing existing handle fasteners.
3. Electric Start Models Only: Attach battery tray (Ref. No.
43) to left engine rail using fasteners used with handle.
Install a 12 volt type no. 9A1 garden tractor battery 32 amp
hour rating, approx. size 7¾” L x 5” W x 6” H (not included)
onto battery tray. Using hardware included with pump,
insert hook bolts through battery tray holes, thread facing
up. Attach battery box hold down bar across battery and
thread wing nuts onto hook bolts. Refer to engine manual
for proper wiring instructions.
NOTE: Model 3993-Z6 battery tray mounts foward as in picture
below.
DESCRIPTION
This trash pump is a heavy duty, centrifugal, engine-driven, self-priming (to 20 ft. lift after initially lling casing with liquid) portable unit. Pump is equipped with
precision lapped mechanical seal to reduce the likelihood of leakage and a clog-resistant impeller capable of handling solids up to 2” diameter. Units are used
to handle water containing stones, sticks, mud and other solids (up to 25% by volume). O-ring sealed ange connections facilitate easy removal of suction and
discharge lines. Handles liquids from 40º to 180º F (4º to 82º C). For use with nonammable uids compatible with pump component materials.
All models come standard with manual recoil starter, E-start models 3993-96, 3993-Z6 and 3994-96 feature in addition a 12V electric starter switch and cables.
5” W x 7¾” L x 5” H battery holder included. (Battery not included; obtain 12V, 32 amp hour battery from local lawn and garden shop).
Pump and engine are mounted on rugged transport dolly with fully pneumatic 16” ball bearing wheels. Proper weight distribution ensures easy portability, yet
pump is stable when operating. Four position discharge manifold provides a choice in placing hose.

Specications Information and Repair Parts Manual 3993-96, 3993-Z6, 3994-96 & 4210-96
3993-254-00 2 3/2017
MAINTENANCE
MECHANICAL SEAL REPLACEMENT
Refer to Figures 1 and 2
NOTE: Always replace the seal seat (Ref. No. 12), seal head
(Ref. No. 13) and shaft sleeve (Ref. No. 3) to ensure proper
mating of mechanical seal components!
See Figure 1
1. Unthread cap screws (Ref. No. 20) and remove casing
(Ref. No. 19) and casing seal (Ref. No. 37) from casing
cover (Ref. No. 6).
2. Unthread screws (Ref. No. 15) and remove volute (Ref. No.
14) from casing cover.
3. Unscrew impeller (Ref. No. 2) from the engine shaft.
Remove the impeller shim (Ref. No. 5), shaft sleeve and
seal head from engine shaft. Use a rubber mallet or soft
block of wood to loosen impeller. Turn it counterclockwise.
Disconnect spark plug wire and battery to prevent
accidental starting.
4. Unthread cap screws (Ref. No. 9) and remove the adapter
(Ref. No. 7) and casing cover from the engine mounting
face.
5. Push seal seat from the casing cover recess with a
screwdriver.
6. Clean the casing cover recess before inserting a new seal
seat.
7. Carefully wipe the polished surface of the new seal seat
with a clean cloth.
8. Wet the rubber portion of the seal seat with a light coating
of soapy water.
9. Press the new seal seat squarely into the cavity in the
casing cover. If the seal seat does not press squarely into
the cavity, it can be adjusted in place by pushing on it with
a piece of pipe. Always use a piece of cardboard between
the pipe and the seal seat to avoid scratching the seal
seat. (This is a lapped surface and must be handled very
carefully).
10. After the seal seat is in place, ensure that it is clean and
has not been marred.
11. Using a clean cloth, wipe the shaft and make certain that it
is perfectly clean.
12. Secure the adapter on the engine mounting face.
NOTE: Tighten cap screws EVENLY to avoid cocking rabbet on
engine mounting face.
13. Apply a light coating of soapy water to the inside rubber
portion of seal head and slide onto the shaft sleeve. Slip
the shaft sleeve with seal head onto the engine shaft.
IMPORTANT: Before installing new shaft sleeve, apply a bead
of non hardening, pliable sealant (such as Permatex® Form-A-
Gasket® No. 2) around motor shaft shoulder.
Do not touch or wipe the face of the polished part of the
seal head.
14. Replace any impeller shims removed in disassembly.
15. Screw the impeller back in place tightening until it is seated
against shims and shaft sleeve.
NOTE: Check to be sure that the shaft sleeve (Ref. No. 3) is in
place against engine shaft shoulder. Model 3993-96 requires a
shaft ange (Ref. No. 4).
16. Remount volute with fasteners.
17. Refer to section titled Shim Adjustment at this time if shaft
sleeve or any other parts listed therein have been replaced.
18. Inspect position of apper valve assembly (Ref. No. 16) to
ensure proper movement and sealing.
19. Replace o-ring seal on volute rabbet.
NOTE: Always inspect o-ring seals. Replace when cracked or
worn. Wet o-ring with soapy water for ease of assembly.
20. Remount casing.
21. Remount any other parts and reconnect spark plug wire
and battery (if so equipped). Pump should now run with
renewed original performance.
SHIM ADJUSTMENT
1. When installing a replacement impeller, engine, shaft
sleeve, adapter, or volute, it may be necessary to vary the
number of impeller shims (Ref. No. 5) that will be required.
This is easily done by adding one shim more than was
removed and reassembling the pump as described in
Mechanical Seal Replacement section.
2. Ensure that volute (Ref. No. 14) and casing cover (Ref. No.
6) are tted rmly (check fastener Ref. No. 15). Remove
spark plug wire from engine and turn engine over by pulling
the recoil starter. If engine does not turn freely, disassemble
pump and remove one shim.
NOTE: When adding or removing shims, it is best to proceed
with a 0.010” increment each time. If engine does turn freely,
add shims until it does strike, then remove a 0.010” shim. This
should allow proper clearance.
4-INCH TRASH PUMP
Figure 1 - Mechanical Seal

Specications Information and Repair Parts Manual 3993-96, 3993-Z6, 3994-96 & 4210-96
3993-254-00 3 3/2017
3. Proper running clearance is 0.010”.
4. Follow the above procedure until proper clearance is
obtained. This will ensure maximum performance.
IMPELLER AND VOLUTE REPLACEMENT
Impeller (Ref. No. 2) and volute (Ref. No. 14) are subject to
wear only by abrasive sand or sediment laden liquids. If badly
worn, all these parts can be replaced easily and the pump thus
restored to full e󰀩ciency.
NOTE: When the clearance between the impeller and the volute
exceeds 1/16” at the face of the impeller or 1/8” on the outside
diameter of the impeller, it may be necessary to take corrective
action. The increased clearance can cause lengthened priming
times and reduced pumping capacity. If both the priming and
capacity of your unit are satisfactory for your application, it is
recommended that no corrective maintenance be performed
regardless of what clearances on your unit may have developed,
since the increased clearances in themselves are not generally
harmful to your pump. Normally, new pump clearances can
be restored by simply shimming behind the impeller. (Add
shim washers, Ref. No. 5). If the impeller is badly worn it is
recommended that the impeller be replaced. This is usually
all that is required since only on unusually abrasive services
does the cast iron wear plate show deterioration. Occasionally
a stone or hard object might get caught in the impeller and
cause damage to the volute/cut water. In these cases, follow
the instructions below for replacement and refer to Figure 2.
1. Disassemble pump for access as described in
MECHANICAL SEAL REPLACEMENT, steps 1 and 2.
2. Replace parts as necessary.
NOTE: When replacing volute, attach apper valve assembly
(Ref. No. 16) to new volute with fasteners (Ref. No. 18).
NOTE: Before installing new parts, clean all mating surfaces
thoroughly. For information pertaining to the engine and
engine parts, consult the Engine Manual or contact the nearest
authorized service representative or the manufacturer.
CLEANING
These units are designed so that for most clean out or clogging
problems it should not be necessary to remove hoses or piping.
The suction area and impeller chambers can be reached by
removing (2) threaded handles (Ref. No. 26) and removing
suction clean out cover plate (Ref. No. 25) and gasket (Ref.
No. 36).
NOTE: When replacing clean out cover plate, carefully wipe
clean all surfaces on which the gasket has contact. Also, make
sure the gasket is in position. The screen in the spark arrester
should be checked.
4-INCH TRASH PUMP

Specications Information and Repair Parts Manual 3993-96, 3993-Z6, 3994-96 & 4210-96
3993-254-00 4 3/2017
For Repair Parts contact dealer where pump was purchased.
Please provide following information:
-Model Number
-Serial Number (if any)
Part description and number as shown in parts list
Figure 2 - Repair Parts Illustrations
4-INCH TRASH PUMP

Specications Information and Repair Parts Manual 3993-96, 3993-Z6, 3994-96 & 4210-96
3993-254-00 5 3/2017
Repair Parts List
Ref. Part Number for Models:
No. Description 4210-96 3993-96 3993-Z6 3994-96 Qty.
1 Engine 1639-033-00 1639-063-00 1630-050-00 1639-031-00 1
2 Impeller Kit 3945-014-95 3945-013-95 3945-014-95 3945-015-95 1
(Includes Ref. Nos. 2, 3, 4 & 5)
3 Shaft Sleeve 1555-143-00 &
Incl. w/Ref 2
1555-149-00 &
Incl. w/Ref 2
1555-143-00 &
Incl. w/Ref 2
1555-143-00 &
Incl. w/Ref 2
1
4 Shaft Flange N/A Incl. w/Ref 2 N/A N/A 1
5 Impeller Shim Kit 1656-000-90
& Incl. w/Ref 2
1656-000-90
& Incl. w/Ref 2
1656-000-90
& Incl. w/Ref 2
1656-000-90
& Incl. w/Ref 2
1
6 Casing Cover Kit 3993-020-96 3993-020-96 3993-022-96 3993-020-96 1
(Includes Ref. Nos. 6, 7, 8 & 9)
7 Adapter Incl. w/Ref 6 Incl. w/Ref 6 Incl. w/Ref 6 Incl. w/Ref 6 1
8 Hex Screw Incl. w/Ref 6 Incl. w/Ref 6 Incl. w/Ref 6 Incl. w/Ref 6 6
9 Hex Screw Incl. w/Ref 6 Incl. w/Ref 6 Incl. w/Ref 6 Incl. w/Ref 6 4
10 Wear Plate Kit 2182-004-90 2182-004-90 2182-004-90 2182-004-90 1
(Includes Ref. Nos. 10 & 11)
11 Flat Head Screw Incl. w/Ref 10 Incl. w/Ref 10 Incl. w/Ref 10 Incl. w/Ref 10 2
12,13 Seal Assembly-Carbon/SIC/Viton (standard) 1640-163-94 1640-163-94 1640-163-94 1640-163-94 1
Seal Assembly-SIC/SIC/Viton (optional) 1640-167-90 1640-167-90 1640-167-90 1640-167-90 1
14 Volute Kit 399C-150-95 399C-150-95 399C-150-95 399C-150-95 1
(Includes Ref. Nos. 14 & 15)
15 Hex Screw Incl. w/Ref 14 Incl. w/Ref 14 Incl. w/Ref 14 Incl. w/Ref 14 2
16 Check Valve Kit-Buna-N (standard) 1990-005-90 1990-005-90 1990-005-90 1990-005-90 1
Check Valve Kit-EPR/EPDM (optional) 1990-019-90 1990-019-90 1990-019-90 1990-019-90 1
Check Valve Kit-Viton (optional) 1990-013-90 1990-013-90 1990-013-90 1990-013-90 1
(Includes Ref. Nos. 16, 17 & 18)
17 Retainer Pin Incl. w/Ref 16 Incl. w/Ref 16 Incl. w/Ref 16 Incl. w/Ref 16 4
18 Flat Head Screw Incl. w/Ref 16 Incl. w/Ref 16 Incl. w/Ref 16 Incl. w/Ref 16 2
19 Casing Kit 2116-001-96 2116-001-96 2116-001-96 2116-001-96 1
(Includes Ref. Nos. 19, 20, 21, 22 & 23)
20 Hex Bolt Incl. w/Ref 19 Incl. w/Ref 19 Incl. w/Ref 19 Incl. w/Ref 19 4
21 Flat Washer Incl. w/Ref 19 Incl. w/Ref 19 Incl. w/Ref 19 Incl. w/Ref 19 8
22 Hex Nut Incl. w/Ref 19 Incl. w/Ref 19 Incl. w/Ref 19 Incl. w/Ref 19 4
23 1/2" NPT Plug Incl. w/Ref 19 Incl. w/Ref 19 Incl. w/Ref 19 Incl. w/Ref 19 1
24 Casing Foot Kit 3993-109-90 3993-109-90 3993-109-90 3993-109-90 1
(includes 2 feet and mounting hardware)
25 Clean Out Cover Kit 2115-002-95 2115-002-95 2115-002-95 2115-002-95 1
(Includes Ref. Nos. 25 & 26)
26 Handle Stud Incl. w/Ref 25 Incl. w/Ref 25 Incl. w/Ref 25 Incl. w/Ref 25 2
27 Suction Flange Kit 3993-050-95 3993-050-95 3993-050-95 3993-050-95 1
(Includes Ref. Nos. 27, 28 & 29)
28 Hex Screw Incl. w/Ref 27 Incl. w/Ref 27 Incl. w/Ref 27 Incl. w/Ref 27 4
29 Lock Washer Incl. w/Ref 27 Incl. w/Ref 27 Incl. w/Ref 27 Incl. w/Ref 27 4
30 Discharge Manifold Kit 3993-080-95 3993-080-95 3993-080-95 3993-080-95 1
(Includes Ref. Nos. 30, 31 & 32)
31 Hex Screw Incl. w/Ref 30 Incl. w/Ref 30 Incl. w/Ref 30 Incl. w/Ref 30 4
32 Lock Washer Incl. w/Ref 30 Incl. w/Ref 30 Incl. w/Ref 30 Incl. w/Ref 30 4
33 Fill Plug Kit-Buna-N oring (standard) 3SXB-170-90 3SXB-170-90 3SXB-170-90 3SXB-170-90 1
Fill Plug Kit-EPR/EPDM oring (optional) 3SXE-170-90 3SXE-170-90 3SXE-170-90 3SXE-170-90 1
Fill Plug Kit-Viton oring (optional) 3SXV-170-90 3SXV-170-90 3SXV-170-90 3SXV-170-90 1
(Includes Ref. Nos. 33 & 34)
34 #117 O-ring Incl. w/Ref 33 Incl. w/Ref 33 Incl. w/Ref 33 Incl. w/Ref 33 1

Specications Information and Repair Parts Manual 3993-96, 3993-Z6, 3994-96 & 4210-96
3993-254-00 6 3/2017
Ref. Part Number for Models:
No. Description 4210-96 3993-96 3993-Z6 3994-96 Qty.
KIT Gasket Kit-Buna-N (standard) 3993-301-90 3993-301-90 3993-301-90 3993-301-90 1
Gasket Kit-EPR/EPDM (optional) 3993-301-91 3993-301-91 3993-301-91 3993-301-91 1
Gasket Kit-Viton (optional) 3993-301-92 3993-301-92 3993-301-92 3993-301-92 1
(includes Ref. Nos. 34, 35, 36 & 37)
35 Flange Gasket Incl. w/Ref KIT Incl. w/Ref KIT Incl. w/Ref KIT Incl. w/Ref KIT 2
36 Clean Out Cover Gasket Incl. w/Ref KIT Incl. w/Ref KIT Incl. w/Ref KIT Incl. w/Ref KIT 1
37 #276 O-ring Incl. w/Ref KIT Incl. w/Ref KIT Incl. w/Ref KIT Incl. w/Ref KIT 1
38 Mount hardware kit 3993-107-90 3993-107-90 4S13-100-90 3993-107-90 1
(includes raising blocks, bolts, nuts & washers)
39 Suction Strainer 1681-001-00 1681-001-00 1681-001-00 1681-001-00 1
40 Frame Rail Kit 3993-111-90 3993-111-90 3993-111-90 3993-111-90 2
(includes 1 rail, bolts & nuts)
41 Axle Rail Kit 3993-110-90 3993-110-90 3993-110-90 3993-110-90 1
(includes axles assembled to rail, bolts & nuts)
42 Handle Kit 3993-100-90 3993-100-90 3993-100-90 3993-100-90 1
(includes handle, 4 bolts & nuts)
43 Battery Tray Kit N/A 3993-106-90 3993-106-90 3993-106-90 1
(includes base tray, hold down, J bolts & wing nuts)
44 Tire/Wheel 1685-000-00 1685-000-00 1685-000-00 1685-000-00 2
‡ Battery Cable Assembly (9" Black) N/A 1639-007-90 N/A 1639-007-90 1
‡ Battery Cable Assembly (9" Red) N/A 3102-107-90 N/A 3102-107-90 1
‡ Battery Cable Assembly (12" Black) N/A N/A 3102-104-90 N/A 1
‡ Battery Cable Assembly (30" Red) N/A N/A 3102-106-90 N/A 1
(‡) Not Shown
Repair Parts List - CONTINUED

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