Walker A21 User Manual

A21 Hi-Dump® Kit

Operator’s Manual

Safety, Assembly, Operation, and Maintenance

A21 compatible with Models D/T (10.0 Catcher Box)

Please Read and Save These Instructions

For Safety, Read All Assembly and Operation Instructions
Prior to Operating Attachment

Beginning S/N: 2018-5524

P/N: 8404-11

Foreword

Thank you. . .for purchasing the Walker Hi-Dump® Kit for your Walker Mower. Every effort has
been made to provide you with the most reliable machine on the market, and we are sure you will

be among our many satised customers. If for any reason this product does not perform to your

expectations, please contact your local dealer. Every customer is important to us. Your satisfaction
is our goal.

Please. . .read this manual thoroughly! Before you operate your machine, please read this entire
manual. Some of the information is crucial for proper operation - it will help protect your investment
and ensure that the machine performs to your satisfaction. Some of the information is important
to your safety, and must be read and understood to help prevent possible injury to the operator

or others. If anything in this manual is confusing or hard to understand, please contact your local
authorized dealer or call our service department, at [phone], for clarication before operating

or servicing this machine.

This manual covers the A21 (8400A) Hi-Dump® installed on Model D or T.

All shields and guards must be in place for the proper and safe operation of this machine.
Where they are shown removed in this manual, it is for illustration purposes only. Do not operate

this machine unless all shields and guards are in place.

Walker Mfg. Co. is continually striving to improve the design and performance of its products.

We reserve the right to make changes in specications and design without thereby incurring any

obligation relative to previously manufactured products.

Sincerely,

WALKER MANUFACTURING COMPANY

Bob Walker, President

i

Table of Contents

General Information 1

HIGHLIGHTED INFORMATION 1

GLOSSARY 1

IDENTIFYING NUMBER LOCATIONS 1

SERVICING OF HYDRAULIC POWER UNIT 2

UNIT DESCRIPTION 2

CONFIGURATION NOTE 2

Specications 3

Safety Instructions 4

BEFORE OPERATING 4

OPERATING 6

MAINTENANCE 8

SAFETY, CONTROL,

AND INSTRUCTION DECALS 9

Assembly Instructions 10

INSTALLING A21 HI-DUMP® ON TRACTOR 10

Parts List/Diagram 23

HI-DUMP® ASSEMBLY 23

HI-DUMP® HYDRAULICS 25

MAINTENANCE AND SERVICE

RECORD SHEET 27

Warranty 28

Operating Instructions 17

HI-DUMP® OPERATION 17

Maintenance Instructions 19

CHECKING OIL LEVEL 19

LUBRICATION 19

Grease Fitting and Oil Point
Lubrication Diagram 20

ADJUSTMENTS 21

Catcher Box Clearance
with Body Chute 21

Door Opening Cable Tension 21

Control Lift Rod 21

ii

General Information

HIGHLIGHTED INFORMATION

Walker Manufacturing recommends that any service
requiring special training or tools be performed by
an authorized Walker Tractor dealer. There are sev­eral general practices to be aware of in the area of
safety. Most accidents associated with the opera­tion or maintenance of a Walker Tractor are caused

by disregarding basic safety precautions or specic

warnings. Such accidents, in most cases, can be
prevented by being aware of the dangers present.

Information of special importance has been high­lighted in bold type in this manual. Refer to Safety

Instructions for the meanings of DANGER, WARN-
ING, CAUTION, IMPORTANT, and NOTE.

GLOSSARY

There are many terms that are either unique to this
equipment or that are used as acronyms. The fol­lowing terms and their denitions will help while us­ing this manual:

● FORWARD SPEED CONTROL (FSC) controls

the maximum forward speed of the tractor; func­tioning as a cruise control.

IDENTIFYING NUMBER LOCATIONS

The Hi-Dump® serial number is afxed to the LH
side of the main frame weldment. Model and serial
numbers are helpful when obtaining replacement
parts and maintenance assistance. For ready refer­ence, please record these numbers in the space
provided.

Hi-Dump Serial No.

Date of Purchase

Refer to the Operator’s Manual that accompanies

the tractor for the location of the tractor serial num­ber.

Serial Number

● GRASS HANDLING SYSTEM (GHS®) collects

mowed material and deposits it in the catcher.

● HI-DUMP® is a power lifting and dumping mech-

anism for the GHS catcher box controlled from

the operator’s seat.

● LEFT HAND (LH) refers to the left-hand side of

the tractor when the operator is seated facing
forward in the tractor seat.

● POWER TAKE-OFF (PTO) transmits engine

power to run the cutter blades and GHS blower.

● RIGHT HAND (RH) refers to the right-hand side

of the tractor when the operator is seated facing
forward in the tractor seat.

● STEERING LEVERS steer the tractor by con-

trolling the dual hydrostatic transmissions.

● TRACTOR is the prime mover, including the

engine, drivetrain, operator seat, and controls to
operate the mower.

A21 Hi-Dump Serial Number Location

(Top View)

1

General Information

SERVICING OF HYDRAULIC POWER UNIT

Only routine maintenance and general service in­structions are provided in this manual. For service
of the hydraulic power unit during the limited warran-
ty period, contact your authorized Walker dealer.
Any unauthorized work done on the hydraulic
power unit during the warranty period may void the
warranty. If you have any difculty nding an autho-
rized outlet or obtaining warranty service, please
contact our Service Department for assistance:

Walker Manufacturing Company

5925 E. Harmony Road

Fort Collins, CO 80528

1-970-221-5614

www.walker.com

UNIT DESCRIPTION

With the optional Hi-Dump® kit installed, the opera-

tor raises and dumps the GHS catcher box while

seated in the seat. Two toggle switches operate
independent hydraulic cylinders to raise, lower and
dump the catcher. The back door automatically
opens and closes during the dump cycle. The catch­er may be dumped at any raised position (Normal

Operating-Intermediate-Fully Raised).

CONFIGURATION NOTE

When Hi-Dump® is installed, the optional single
wide tail wheel (P/N 8049) on the tractor is not rec-

ommended due to tail weight and extra turning resis­tance. Use the standard dual tail wheel (P/N 7420-

20).

2

Specications

A21 HI-DUMP® KIT

MODEL A21

Catcher Lift Height in. (cm) 67 (170)

Maximum Lift Rating lb (kg) 200 (91)

Lift/Dump Cycle Time 20 seconds

Lift/Dump Controls Individual Toggle Switch with Solenoid Activated

Valves Operating Hydraulic Cylinders

Weight Installed lb (kg) 150 (68)

Height Increase (Tractor) in. (cm) 3 (8)

Hydraulic Oil Chevron Rykon Premium Oil ISO 68 or

Equivalent

Oil Capacity  oz (L) 32 (.95)

NOTE: The manufacturer reserves the right to make changes in specications shown herein at any time without

notice or obligation.

3

Safety Instructions

Pay particular attention to any information labeled

DANGER, WARNING, CAUTION, IMPORTANT,
and NOTE in this manual.

When you see the Safety Alert Symbol ( ), read,
understand, and follow the instructions. Fail ure to
comply with safety instructions may result in per­sonal injury.

The seriousness or degree of importance of each

type of information is dened as follows:

DANGER

An IMMEDIATE hazard that WILL result in
severe personal injury or DEATH, if warn­ing is ignored and proper safety precau­tions are not taken.

WARNING

A POTENTIAL hazard that COULD result in
severe personal injury or DEATH, if warn­ing is ignored and proper safety precau­tions are not taken.

Walker Manufacturing cannot predict every poten­tially dangerous situation. Therefore, items labeled
as such in this manual do not cover all conceivable
situations. Any person using procedures, tools, or
control techniques not recommended by Walker
Manufacturing must take full responsibility for safety.

The Walker Rider Lawnmower has been designed
with many safety features to protect the operator
from personal harm or injury. However, it is neces­sary for the operator to use safe operating proce­dures at all times. Failure to follow safety instruc-

tions contained in this manual may result in
personal injury or damage to equipment or prop­erty.

If you have any questions concerning setup, opera­tion, maintenance, or safety, please contact your
authorized Walker Mower dealer or call Walker Man­ufacturing Company at [phone].

BEFORE OPERATING

1. Read and understand the contents of this
Operator’s Manual before starting and oper­ating the machine. Become thoroughly famil-

iar with all machine controls and how to stop the
machine and disengage the controls quickly.

Replacement Operator’s Manuals are available

by sending the Model and Serial Number to:

Walker Manufacturing Company

5925 East Harmony Road

Fort Collins, CO 80528

CAUTION

Possible hazards or unsafe practices that
MAY result in MODERATE personal injury
or property damage, or machine damage, if
warning is ignored and proper safety pre­cautions are not taken.

IMPORTANT: Identies mechanical information

demanding special attention, since it deals with the
possibility of damaging a part or parts of the ma­chine.

NOTE: Identies information worthy of special
attention.

2. Never allow children to operate rider mower.
Do not allow adults to operate without proper
instruction.

3. Clear the area to be mowed of any foreign
objects which may be picked up and thrown by

cutter blades. Pick up all sticks, stones, wire,

and any other debris.

4. Keep everyone, especially children and pets, a
safe distance away from the area being mowed.

Do not mow with bystanders in the area.

5. Do not operate the machine barefoot or wearing
sandals, sneakers, tennis shoes, or similar
lightweight footwear. Wear substantial

protective footwear.

4

Safety Instructions

6. Do not wear loose tting clothing that could get

caught in moving parts. Do not operate this ma ­chine while wearing shorts; always wear
adequate protective clothing, including long
pants. Wearing safety glasses, safety shoes,
and a helmet is advisable and required by some
local ordinances and insurance regulations.

7. Prolonged exposure to loud noise can cause

impairment or loss of hearing. Operator hear-
ing protection is recommended; particularly

for continuous operation of the GHS Model due

to blower noise level. Wear a suitable hearing
protective device, such as earmuffs or earplugs.

8. Keep all protective shields and safety de-

vices in place. If a protective shield, safety

device, or decal is damaged, unusable, or
missing, repair or replace it before operating
the machine.

9. Be sure interlock switches are functioning
correctly, so the engine cannot be started
unless the Forward Speed Control lever is in the

NEUTRAL-PARK position, the PTO clutch is in

the DISENGAGED position, and the Parking
Brake in the ENGAGED position. Also, the
engine should stop if the operator lifts off the
seat with any one or more of these controls
in the operating position: (1) Forward Speed
Control (FSC) out of NEUTRAL-PARK, (2)

PTO Clutch ENGAGED, or (3) Parking Brake
DISENGAGED.

11. Never attempt to make any adjustments
while the engine is running, except where

specically instructed to do so.

12. The electrical system battery contains sulfuric
acid. Avoid any contact with skin, eyes, and
clothing. Keep the battery and acid out of reach
of children.

WARNING

This product can expose you to chemicals
including Di-(2-ethylhexyl) phthalate which
is known to the State of California to cause
cancer, and Di-(2-ethylhexyl) phthalate,
which is known to the State of California
to cause birth defects or other repro­ductive harm. For more information go to
www.P65Warnings.ca.gov.

NOTE: There is a 1/2 second time delay func-

tion on the seat switch to avoid engine power
interruption when driving over bumps.

10. Handle gasoline with care. Gasoline is highly

ammable and its vapors are explosive:

a. Use an approved fuel container.

b. Never add fuel to a running engine or hot

engine (allow hot engine to cool several
minutes).

c. Keep matches, cigarettes, cigars, pipes,

open ames, or sparks away from the fuel

tank and fuel container.

d. Always ll the fuel tank outdoors using

care. Fill to about one inch from the top of
the tank. Use a funnel or spout to prevent
spilling.

e. Replace the machine fuel cap and contain-

er cap securely and clean up any spilled
fuel before starting the engine.

5

Safety Instructions

OPERATING

1. Operate the machine only in daylight or in

good articial light with good visibility of areas

being mowed.

2. Sit on the seat when starting the engine and
operating the machine. Keep feet on the deck
footrests at all times when the tractor is moving

and/or the mower blades are operating. Never
operate the tractor without a deck or imple­ment installed.

3. For a beginning operator, learn to steer (ma­neuver) the tractor with a slow engine speed
before attempting any mowing operation.

Be aware that, with the front mounted mower

conguration, the back of the machine swings

to the outside during turns.

DANGER

Do not operate around overhanging tree
branches or bushes at the same height as
the operator’s torso and head where inad­vertent contact may cause injury.

7. Do not operate machine if the operator pres­ence safety switch system is not working.

Verify proper operation by having the operator
lift off the seat with the engine running and mov­ing three controls, one at a time; (1) Move the
FSC lever out of the NEUTRAL-PARK position,

(2) Engage the PTO Clutch, and (3) Disengage
the Parking Brake. Moving any of these con­trols should stop the engine after a 1/2 second

delay.

8. Do not run the engine in a conned area
without adequate ventilation. Exhaust fumes
are hazardous and can be deadly.

9. Do not carry passengers - maximum seating
capacity is one (1) person.

10. Watch for holes, rocks, and roots in the terrain
and for other hidden hazards. When mowing
tall grass, mow higher than desired to expose
any hidden obstacles. Then, clean the area
and mow to the desired height.

11. Avoid sudden starts or stops. Before back-
ing the machine up, look to the rear to be sure
no one is behind the machine. Watch carefully
for trafc when crossing or working near road­ways.

4. Remember, for an emergency stop, the forward
motion of the tractor can always be stopped by
pulling the Forward Speed Control (FSC) into
the NEUTRAL-PARK position.

5. In case either of the transmission drive belts
break during operation, and if the machine is on
a slope, the machine will freewheel down the
slope. To maintain control, immediately (1)
Release the steering levers and simultaneously
(2) Move the FSC to the NEUTRAL-PARK po-
sition. When the machine is stopped or moving
slowly, engage the parking brake.

NOTE: The emergency stop procedure is ex­actly the same procedure used to normally stop
and park the machine.

6. Disengage the PTO clutch and put the FSC in
the NEUTRAL-PARK position before starting
the engine (an ignition interlock switch normally
prevents starting of the tractor if these controls
are in the OPERATING position).

12. When moving forward, do not suddenly put the

tractor in reverse by rapidly pulling on the steer­ing levers, especially when going downhill, as
this can lift the tractor tail wheel off the ground
and set up a bucking motion due to operator

overcontrol. If bucking does occur, immediately

stop the bucking action by pulling the Forward
Speed Control (FSC) lever into the NEUTRAL-
PARK position.

13. Disengage the blade drive when transporting

the machine across drives, sidewalks, etc. Nev-

er raise the mower deck while blades are
rotating.

DANGER

Do not mow or dump grass within 5 feet
(1.5 meters) of an embankment or retaining
wall with drop off.

6

Safety Instructions

14. The maximum recommended slope operat­ing angle is 15 degrees or 26% grade. When

operating the machine on a slope, reduce speed
and use caution to start, stop, and maneuver.
To prevent tipping or loss of control of the ma­chine, avoid sharp turns or sudden changes in
direction. Do not operate the machine on a

slope greater than 15 degrees.

15. Never adjust cutting height with the engine
running. Before adjusting cutting height or

servicing, disengage the blade clutch (PTO),

stop the engine, and remove the ignition key.
Wait for all movement to stop before getting off
the seat.

NOTE: A blade/blower brake should normally
stop drive line rotation within ve (5) seconds of
disengaging the PTO clutch.

16. For side discharge mower decks, do not oper-
ate with the grass deector shield removed.
Keep the deector in the lowest possible posi­tion.

17. When using the tilt-up deck, observe the fol-

lowing:

a. Do not move tractor with deck in tilt-up

position.

b. Never tilt body forward with deck in tilt-up

position.

18. For GHS equipped models, do not operate the

machine with the grass catcher in the DUMP
position or with the back door OPEN. Dan-

gerous projectiles may be thrown out of the dis­charge chute or the back of the grass catcher.

20. If the cutting blades strike a solid object or the

machine begins to vibrate abnormally, immedi-

ately disengage the blade clutch (PTO), stop
the engine, and wait for all moving parts to
stop. To prevent accidental starting, discon-

nect the spark plug wires. Thoroughly inspect
the mower and repair any damage before re­starting the engine and operating the mower.
Make sure cutter blades are in good condition
and blade nuts are torqued to 60 lb·ft (81 N·m)
for gear driven decks, and blade bolts torqued
to 70 lb·ft (95 N·m) for belt driven decks.

21. Do not touch the engine or mufer while

the engine is running or immediately after
stop ping the engine. These areas may be hot
enough to cause serious burns.

22. When leaving the machine unattended, disen-

gage the blade clutch (PTO), stop the en­gine, and remove the key.

INSTRUCTIONS FOR HI-DUMP® OPERATION

1. When operating the Hi-Dump®, the operator
should be in the seat with feet on the footrests,
the FSC in NEUTRAL-PARK position and the
parking brake engaged.

2. To avoid tipping over, the tractor should be
parked on LEVEL GROUND when raising/
dumping the catcher with Hi-Dump®.

3. Make sure bystanders stay clear of the area
when the Hi-Dump® is operating.

4. Do not attempt to use the optional dump bag
or dump into any other bag with the Hi-Dump®.

19. In case of a clogged or plugged mower deck

or GHS catching system:

a. Disengage the blade clutch (PTO), engage

the parking brake, and turn the engine off
before leaving the seat.

b. LOOK to make sure blade drive shaft and

blower drive pulley movement has stopped
before trying to unclog the system.

c. Disconnect the spark plug wires.

d. Never place hands under the deck or in the

GHS blower - use a stick or similar tool to

remove clogged material.

7