Technical Service Bulletin
Date: July 8, 2021
Bulletin Name: FDM-TSB-003
Model: Oshkosh S-Series
Units Affected: SN 792616 - 813126

2.0 Water Add Valve Retrofit

Purpose:
This bulletin provides information and instruction on removing the water add valve from the charge hopper
location and installing a new air operated valve at the water manifold located on the frame rail. Moving the water
add valve eliminates freezing issues and improves water system performance.

Notice:
• This bulletin should be read and understood in its entirety before performing this procedure.
• All procedures outlined in the bulletin must be performed by skilled service personnel. Refer to the product
service manual for descriptions of maintenance procedures.

SAFETY NOTICE

SAFETY NOTICE

Perform your company’s Lockout/Tagout
procedure. If your company does not have a
Lockout/Tagout procedure, follow OSHA
1910.147 and 1910.146 Confined Space as
appropriate.

Use appropriate Personal Protective
Equipment (PPE) as required by your
company.

Tools and Equipment Required:
Customer to supply:
•
•
•
•

Torque wrench (inch pounds)
Torque wrench (foot pounds)
Hand tools
Zip ties

1

Parts Required:
Kit 1636092 includes the following parts
Item

Part Number

Description

Qty.

1

A000H803

CLAMP,WORM 1.06-0.56

2

A000V756

HOSE,WATER 0.63 ID,EPDM,7.5

3

A000V757

WIRE HARN,JUMPER,PRESS,SW

1

4

A000V410

WIRE HARN,JUMPER,WATER ADD

1

5

A000V232

SPCR,.125,WATER MANIFOLD

1

6

A000A503

SCR,FLG,HEX 0.25-20X1.25 G8 MB

2

7

A000A520

SCR,FLG,HEX 0.31-18X1.75 G8 MB

1

8

A000A689

NUT,FLG,LKDT 0.31-18 G8 MB

1

2
7.5”

9

A000A433

VALVE,AIR 3W2P NC,ELEC

1

10

A000D602

FTG,T 4PTC-4NPTF-4PTC FMF PL

1

11

A000V233

TUBING,NY 0.25 BLU 20.0 2528

1

12

A000V234

TUBING,NY 0.25 BLU 21.0 2520

1

13

A000V451

LABEL,INFO,DRAIN VALVES,PC

1

Manifold Assembly
14

A000U509

VALVE,WTR,PISTON,AIR

1

15

A000U648

MANIFOLD,WATER,HEATED,ASSY

1

16

A000N252

FTG,45 16NPT-16NPT MF BR

1

17

A000B732

FTG,PLUG 8NPTF M BR INHEX

1

18

A000B531

FTG,ST 8NPTF-12NPTF FM BR

1

19

A000N133

FTG,45 8NPT-10BEAD MM BR

1

20

A000B293

FTG, 90 4PTC-2NPTF FM PL

1

Drain Assembly
21

A000N254

VALVE,WTR,BALL,MNL,8NPT BR

1

22

A000B517

FTG,ST 8NPTF-8NPTF FM BR

1

23

A000D933

FTG, ST BEAD-NPTF MM BR TAB

1

24

A000B500

FTG,T 8NPTF-8NPTF-8NPTF- MFF BR

1

Hopper Assembly
25

A000U230

FTG,ST 16NPT-16NPT FF BR

2

26

A000U231

FTG,ST 16NPT-16NPT MM BR

1

Procedure:
Lockout/Tagout
1. Place unit on a flat surface, block truck tires, and perform your company’s Lockout/Tagout procedure. If your
company does not have a Lockout/Tagout procedure, follow OSHA 1910.147 and 1910.146 Confined Space as
appropriate.
2. The vehicle’s BATTERY DISCONNECT switch is located on the left-hand side of the battery box. Use the
battery disconnect switch when performing any maintenance so the vehicle cannot accidentally be started.
a. Turn the battery disconnect switch (Figure A, Item 1) counterclockwise so the hole on the switch aligns
with the hole in the bracket (Figure A, Item 2).
b. Install the safety lockout device ring (Figure B, Item 1) through the holes on the battery disconnect switch
and the bracket.
c. Install a padlock (Figure B, Item 2) onto the safety lockout device ring, lock it, and put the key in your
pocket. If more than one person is working on the vehicle, each person must install his or her own padlock.

2

1

DA
NG
ER

Th
be is en
e
e
n
L O r gy
Un
CK sou
th auth
ED rce
OU ha
in is loc oriz
T! s
R im k/t ed
e
ma media ag m rem
rks te ay ova
:
dis re l o
ch sult f
ar g
e.

1

2

2

Figure A

Figure B

Water Add Valve Installation
3. Open air drain valves to drain vehicle’s air system, see Figure 1. Close drain valves when all system air is
drained.

Air
Drain Valves

Figure 1

4. Open the hose and manifold drain valves to drain water from the system, see Figure 2. Close drain valves
when all water is drained.

Water
Drain Valves

Figure 2

3

5. Loosen supply hose clamp and disconnect supply hose from valve assembly, see Figure 3.
6. Remove 3 screws with lock washers securing valve assembly to hopper support, see Figure 3. Set screws
and washers aside for reinstallation later.

Screws and
Lock Washers

Supply
Hose

Hose Clamp

Figure 3

7. Remove U-bolts securing the valve assembly to the mounting bracket and remove valve assembly from
mounting bracket, see Figure 4. Set mounting bracket, U-bolts and hardware aside for reinstallation later.

Mounting
Bracket

U-Bolts

Nuts and Lock
Washers
Figure 4

4

8. Remove hose barb fitting from end of valve assembly, see Figure 5. Set fitting aside for reinstallation later.
9. Remove elbow and tube together from valve assembly, see Figure 5. Set elbow/tube assembly aside for
reinstallation later.
10.

Discard valve and coil assembly.

Barb Fitting
Elbow and Tube
Figure 5

NOTE

Apply pipe sealant to all threaded
connections.
11.

Assemble the top bracket components, see Figure 6.

U-Bolts

Bracket

(removed in Step 7)

(removed in Step 7)

Hose Barb

Elbow/Tube Assembly

(removed in Step 8)