WALTCO HDC-33 User manual

Installation Manual
HDC-33, HDC-44
3300 lb. & 4400 lb. Capacity Cantilever Liftgates
Last Change
GR02912
Date Pages Description
01/2022
All
. New HDC Liftgate released January 2022
Waltco Lift Corp.
Corporate Office United States
1777 Miller Parkway Streetsboro
OH 44241
P: 330.633.9191
F: 330.633.1418
01/2022 Rev 01
80117301
www.HIAB.com
[e-mail]
Phone:
800.411.5685
Fax: [phone]

2
Table of Contents
Introduction ...................................................................................................................................... 3
Safety Information........................................................................................................................... 4
Liftgate Terminology....................................................................................................................... 6
Basic Mounting Requirements...................................................................................................... 8
Liftgate Installation.........................................................................................................................10
Electrical Installation......................................................................................................................16
Electrical Schematics ....................................................................................................................17
Electrical Trouble Shooting ..........................................................................................................25
Battery Connection… .................................................................................................................... 33
Fill Reservoir...................................................................................................................................35
Platform Install................................................................................................................................36
Up-Stop ...........................................................................................................................................39
Platform Tilt/Cylinder Adjustment................................................................................................40
Bumper ............................................................................................................................................44
Swing Door Applications...............................................................................................................44
Check Operation ............................................................................................................................46
Placement of Decals .....................................................................................................................48
Lubrication Instructions.................................................................................................................51
Final Inspection ..............................................................................................................................52
Optional Kit Instructions:
Aux Battery Kit (Truck)..................................................................................................................53
Kit #80001066
Aux Battery Kit (Trailer)
Kit #80001069
Full Door Seal Kit...........................................................................................................................58
Kit #80000573
Cycle Counter Kit...........................................................................................................................63
How to Order Parts........................................................................................................................64
Improper installation of this liftgate could result in severe personal injury or
death.
Read and understand the contents of these instructions before proceeding.
When installed, this liftgate must not alter or prevent vehicle compliance to any
existing state or federal standards.
Each chassis manufacturer’s recommendations should be consulted for
compliance.

3
INTRODUCTION
If anyone observes improper installation, improper operation, or damage, they should immediately
contact a qualified person for assistance and correction. We strongly urge anyone that has any questions
or doubts as to the installation, condition, use, operation, maintenance or repair of the liftgateto contact
us at Waltco where we have qualified personnel that will be happy to assist you. Telephone numbers and
addresses of these locations are listed in the Owner’s Manual and Installation Instructions.
INSTALLATION
Waltco liftgates should only be installed by those with sufficient basic skills to understand the
installation and operation of the liftgate, along with the equipment on which the liftgate is being installed.
Waltco’s installation instructions are not intended to give rationale for all the instructions that are given;
however, it is the intent of these instructions to give the installer both the operations andwhat we
believe to be the most desirable sequence of implementing these operations. These instructions can in
no way expand into an area where they will replace a qualified person, or clear thinking and a basic
knowledge that must be possessed by the installer.
It has been our experience that a knowledgeable journeyman following these instructions and
observing the operation of the liftgate will have a sufficient comprehension of the liftgate to enable this
person to troubleshoot and correct all normal problems that may be encountered.
Failure to follow the installation instructions, adjustments and mounting dimensions may result in
improper and unsafe operation of the liftgate. Unauthorized alterations of the liftgate can cause an
undesirable and dangerous condition.
OWNER’S MANUAL
The Waltco Owner’s Manual is intended to act as a guide for operation and routine maintenance but
is no way intended to encourage usage or repair of the liftgate by those who are not qualified to do so.
The contents of the owner’s manual include, but are not limited to general operation instructions,
routine lubrication, parts lists, and an outline of things that should be checked but may not be obvious
to those not technically qualified. This manual assumes the liftgate is properly installed, undamaged
and operates correctly. Improper installation, improper operation, or damage should be immediately
corrected by a qualified person.
INSPECTION
As part of the regular inspection of a liftgate and after damage or suspicion of an overload, inspect
for wear or structural damage and make necessary repairs or replacements. Check all structural
components and their attachment to the liftgate for cracked welds, loose fasteners, wear and part
deformation. Check cylinder and hose for leaks. Inspections and repairs should be made by a qualified
mechanic.
REPLACEMENT PARTS
Use only Waltco original equipment replacement parts. Components of other liftgate manufacturers
may outwardly appear to be the same but are not interchangeable with Waltco products. Waltco
components are specifically designed for safety requirements, reliability and compatibility with our
products. Refer to your Waltco parts manual when ordering parts. NOTE: When ordering, give model and
serial number of liftgate.
DECALS
It is important that every vehicle that has a WALTCO Liftgate have legible DECALS clearly posted on
the vehicle and an OWNER’S MANUAL in the vehicle at all times as a guide for proper operation and
maintenance.
Additional DECALS and OWNER’S MANUALS can be obtained from WALTCO LIFT CORP.

Chapter 1 Safety Information
4
Read, understand, and follow all of the warning listed below.
Failure to follow these warning could result in severe personal injury or death.
• Read and understand the Owner’s Manual, all decals and warning on liftgate before operating liftgate.
• Do not operate liftgate without a thorough knowledge and understanding of the operation of the liftgate.
• Liftgate hazards can result in crushing or falling.
• This liftgate is designed for loading and unloading of cargo. If personnel are required to ride liftgate, observe
and familiarize yourself with the liftgate operation, decals and manuals. Ensure stable footing at all times.
• Do not ride liftgate with unstable loads.
• Wheeled loads must be properly retained from rolling.
• Tall, high center of gravity loads must be retained from falling over.
• Never overload liftgate:
Load platform as close to the vehicle, and towards the middle of the platform as possible. Refer to owner’s
manual and capacity decal of liftgate for maximum load and load placement.
• Keep hands and feet clear of all potential pinch points.
• Never use liftgate if it makes any unusual noise, has unusual vibration, raises or lowers unevenly, or fails to
operate smoothly.
• Never use liftgate if it shows any signs of structural damage such as cracked welds, bent or distorted
members.
• Do not attempt any repairs unless you are qualified to do so. Care should be taken when work is performed
on a disabled liftgate located near moving traffic. When possible the vehicle should be moved away from
traffic areas for repair. Precautionary measures should be taken to ensure personal safety including those
recommended in Federal Motor Vehicle Safety Standards 571.125.
• When welding to liftgate, or liftgate components, take all necessary safety precautions, including using
respiratory protection and other pertinent personal protective gear when welding harmful materials.
• All protective covers, guards, and safety devices must be in place and access doors closed before operating
liftgate.
• Do not allow anyone to stand in, or near area, in which Platform will open and close before opening or closing
Platform.
• Do not allow anyone to stand near the Platform where a falling load could land on them.
• Platform is always to be properly stored and secured for transit. See the Owner’s Manual for details.
• Take care to retain cargo during transit for liftgate Platforms which function as the tailgate or door of the cargo
area. Small objects can fall through the space between the vehicle and the folded Platform.
• A Lock-Out device or Shut-Off Switch should always be used to prevent unauthorized use of liftgate.
• For liftgates with Runners, never use liftgate if Runners do not travel freely and smoothly.
• For liftgates with Roller Lifting Chain, the Chain should be replaced every (5) five years or 15,000 cycles,
whichever comes first. Replace only with Waltco approved Roller Chain.
• Never transfer loads which exceed lifting capacity on or over any part of the Platform unless the liftgate is
equipped with a special reinforced Platform and Platform Support Bars for use when the Platform is used as
loading ramp (dock board). Refer to the “Using Platform as a loading ramp” Chapter in the Operation
Instructions of the BZ/RZ series Owner’s Manual.
• For liftgates equipped with Trailer Hitches, never exceed the rated capacity of the hitch. Do not exceed the
vehicle’s weight rating. Refer to the vehicle’s Owner’s Manual.
• Vehicle must comply with all state and federal standards.
• Follow the “Maintenance Guide” chapter in the Owner’s Manual.
WARNING

Chapter 1 Safety Information
5
Liftgates with Tilt Function
• Proper use of the Control Switches is of extreme importance.
• Improper use of Tilt Switch could cause load to fall from the Platform or damage the liftgate.
• Platform should be in a generally horizontal position when raising or lowering with a load.
• In any tilt position, the Platform may vary from level while raising or lowering the Platform.
This is the safety alert symbol. This manual uses this symbol to alert you to potential personal injury
hazards.
Obey all safety messages that follow this symbol to avoid personal injury or death.
SIGNAL WORDS
12-2021
WARNING
Indicates a potentially hazardous situation, which if not
avoided, could result in death or serious injury.
Black letters on an orange background
CAUTION
Indicates a potentially hazardous situation, which if not
avoided, may result in minor or moderate injury. May
also be used to alert against unsafe practices.
Black letters on a yellow background.
NOTICE
Indicates a potentially hazardous situation, which if not
avoided, may result in property damage. NOTICE
CAUTION
WARNING

Chapter 2 Liftgate Terminology
6
1. Platform
2. Mount Tube 16
3.
Pump
and
Motor
Tray
4. Lift Arm
15
5. Bumper
6. Lift Cylinder
1
7.
Tilt
Cylinder
8. Upper Lift Arm Pin
9. Lower Lift Arm Pin 14
10. Upper Lift Cylinder Pin 17
11. Lower Lift Cylinder Pin 17
12. Upper Tilt Cylinder Pin 14
13. Lower Tilt Cylinder Pin
14. Marker Lights
15. Sill Extension
16. Mount Plates
17. Cart stop (optional)
GR00828
14
14
12
10
13
11
GR00829

Chapter 2 Liftgate Terminology
7
Explanation
of
Specification
Tag
MODEL
NUMBER
RATED
CAPACITY
Based on an evenly
distributed load on the
platform flat surface.
SERIAL
NUMBER
of liftgate. To be used
when ordering parts or
when contacting Waltco
for service or warranty
questions
DATE
OF
MANUFACTURE
Month / Year
GR00241
HDC33
Level
Lift
3300
lbs.
HDC
44
Level
Lift
4400
lbs.
GR02226
Mount
Tube
Usually
found
on this end
On
some
older
liftgates
may be located here
LOCATION OF SPECIFICATION TAG
Can be found on driver’s side, end of mount tube.

Chapter 3 Basic Mounting Requirements
8
FRAME
WIDTH
45-1/2” MAX
Liftgates can be mounted to trucks and trailers with max
frame
width
45
-
1/2”.
Additional mounting configurations and dimensions may
be
available
by
contacting
the
Waltco
Engineering
Department.
77- 3/4”
GR00655
MOUNTING
BRACKETS
13-1/4
Mounting brackets height may need to be trimmed in
12
order
to
achieve
desired
A
-
dimension.
After
modification
a
minimum
of
6
of
the
outer
holes
must
8-1/4 1-1/8
remain
available
for
use.
IMPORTANT! Do not modify mounting bracket bolts,
nuts
or
mounting
surfaces
that
are
in
contact with
mount
tube.
3-1/4
GR02987
GR00494
MOUNTING DIMENSIONS
Determine bed height. Measure from top of vehicle floor
down to ground.
NOTE: All dimensions when vehicle unloaded on
horizontal surface.
GR00496
CALCULATING MINIMUM A DIMENSION:
The A dimension is the distance from the top of the floor
to the top of the lift gate mount tube.
The mount tube must be installed at least 1-5/8” below
vehicle chassis to allow room for mounting brackets.
The minimum A dimension allowable is the distance
from the top of the floor to the bottom of the vehicle
chassis plus 1-5/8”.

Chapter 3 Basic Mounting Requirements
9
DETERMINING INSTALLATION DIMENSIONS
To determine the installation dimensions:
1. Determine the smallest A dimension your vehicle allows. (Distance from top of floor to bottom of chassis plus
1-5/8”)
2. Using the table below that corresponds to your gate’s arm length, verify that your vehicle is compatible with the max
sill depth, mount tube clearance and max unladen bed height for that A dimension.
3. If necessary, increase the A dimension until the corresponding max sill depth, mount tube clearance and max unladen
bed height for that A dimension are compatible with your vehicle.
4. Very acceptable ground clearance: Ground Clearance = Bed Height – A Dim – 10.25”
NOTE: Minimum allowable bed height is dependent solely on the required ground clearance.
Additional mounting configurations and dimensions may be available by contacting the Waltco Engineering
Department.
Important! Do not exceed the maximum listed bed height for the A dimension used. This can cause damage to
the liftgate and improper proper operation of the liftgate.
HDC 33/44
Short arm, 29-1/2" Optional
A-Dimension Maximum sill depth Mount tube clearance
Max
Unladen
Bed Height
15.5
4
33
43
18
5
31.5
45
20
5.5
30
47
21.75
6.5
28.5
49
23.75
7
26.25
51
25.5
7.75
24.5
52.5
HDC-33/44
Long arm, 34-1/4" Standard
A-Dimension Maximum sill depth Mount tube clearance
Max
unloaded
Bed Height
18.25
5
36.75
49
20.25
5.5
35.5
51
22.25
6.5
34.25
53
24.25
7
32.5
55
26.25
7.5
30.75
57
28
8.25
28.5
59
29.5
9
26.75
60

Chapter 4
Liftgate Installation
10
GR00511
PREPARATION OF BODY
Remove all obstructions that will interfere with liftgate
operation.
Dock bumpers
Trailer hitches
GR00497
If rear sill is deeper than the “Max Sill Depth”, as
indicated in the Mounting Requirements, notch as
shown.
Mark a witness line at center of rear sill. This line will be
used for centering the liftgate later.
NOTCH
REAR
SILL
GR00056
Use 3/16” or 1/4” x 2” steel bar.
Form bar and weld in place.
REINFORCE
SILL
NOTCH

Chapter 4
Liftgate Installation
11
GR00057
If necessary extend chassis frame back to rear sill.
Add bar or angle to cap off frame and tie it in with rear
sill.
Add a tie strap on the side of the chassis frame to tie it
together with the body long member.
REINFORCE
REAR
SILL
AREA
GR00498A
Make two (2) plates with 1-3/16” dia. holes as shown.
Cut a length of 3” angle, or similar material, approx. 70”
long.
CONSTRUCT
MOUNTING
JIG

Chapter 4
Liftgate Installation
12
GR00499
Note:For vehicles with swing doors, refer to section in
back of manual “For Vehicles with Swing Doors”.
Locate and tack-weld the mounting jig to rear sill of
body.
Align the centerline marks of the jig with mark on sill.
Verify
the 1-3/8” and 3-1/8” dimensions.
GR00060
Note:The outer two cylinders are the tilt cylinders.
Do not remove any pins from mount frame.
Remove the temporary shipping pins from the tilt
cylinders and lift arms.
Remove the lock nuts and pins from the lift cylinders
and lift arms.
Disconnect all four (4) cylinders from the lift arms.
MOUNT
LIFTGATE
TO
MOUNTING
JIG

Chapter 4
Liftgate Installation
13
GR00062
Position liftgate mount frame on a floor jack or other
type of lifting device.
Rotate lift arms up to the mounting jig.
Temporarily secure lift arms to mounting jig with long
bolts and nuts supplied with liftgate or platform.
Other means may be used to support
Mount Frame in position. ALWAYS verify
the safety of your supporting method
before proceeding.
GR00061
Check that lift arm assembly pivots freely on pivot pins in
mount frame.
If necessary, loosen nuts on pivot pins indicated.

Chapter 4
Liftgate Installation
14
GR00063
Jack mount frame up to the proper “A” Dimension.
Refer to the Mounting Requirements in this manual.
Note: Use the smallest “A” Dimension per the chart, this
insures the greatest ground clearance.
Important: Top of mount tube is not to contact the
vehicle chassis frame.
Position mount plates over mount tube, and up against
vehicle chassis frame.
Open end of mount plates must face front of vehicle.
TRIM MOUNT PLATE
Rotate liftgate and mount plate so plate is 90° degrees
to chassis frame.
Drill ½” holes, centered in slots, through chassis frame.
Note:In some installations it may be necessary to trim
off top of mount plates to clear body cross members.
After modification a minimum of 6 of the outer holes must
remain available for use.
GR00064

Chapter 4
Liftgate Installation
15
GR00065
MOUNT PLATES BOLTED
INSTALL ENDPLATE
Bolt mount plates to chassis frame and install endplates
onto mount plates.
Using 1/2” bolts and square washers, bolt mount plates
to vehicle chassis frame.
Install endplates as shown with provided nuts and
washers and torque to 85 ft. lbs.
Note: Do not install any more bolts or weld mount plates
to chassis frame at this time.
GR00066
Re-attach lift cylinders to lift arms.
Unbolt lift arms from mounting jig, and lower arms to
ground.
Reinstall lift cylinder pins and locking nuts.
Remove mounting jig from rear sill.

Chapter 4 Liftgate Installation
16
Accessing the Control Card and Power Unit
The lift’s hydraulic unit and its control card are installed
inside the lift’s frame. For access during installation,
service and repair, for example, the protective cap
needs to be dismantled and the hydraulic unit pulled a
little way out of the frame.
To access the control card, follow steps 1 to 3; refitting
is performed in reverse order. To access the hydraulic
unit and oil tank, follow steps 1 to 6; refitting is
performed in reverse order.
1. Remove the protective cap, which is secured with
two quick-release locks.
2. Move the release latch (A) to the left and then fold
out the control card (B), see Image. Reinstall in
reverse order. You may need to remove wire ties
to extend the wires to pull the power unit out.
Always replace wire ties after you are done.
3. Remove the bolt and wing nut securing the power
unit to the base of the tube.
4. Pull the power unit out as far as you can without
damaging the wires.
5. If necessary you can disconnect the connector
from the control card to the power unit.
6. If you need to remove the control card, just lift it
out of the hinges.
7. Carefully place the control card to one side.

17
Rev 08
NOTE:
Do not use the following fluids:
Brake Fluid
Power steering fluid
Automatic Transmission Fluid (ATF)
Fill reservoir
•Fill with recommended fluid or equivalent.
•Fill the reservoir to within 1/2” from the top.
•Fluids are available from the Waltco parts
Dept. 1-800-411-5685 www.waltco.com
Recommended
Fluids
Temperature Range Acceptable Fluids
0
°
to 120
°
F Waltco Biodegradable
LiftlubeTM part #85803860
Shell Tellus S2 V 32
Chevron
Rando
HDZ
32
-20°to 90°FWaltco Biodegradable
LiftLube Arctic part
#85803866
Waltco All Season Hyd Oil
Part 85803867
Shell
Tellus
S2
V
15
Mobil DTE 10 Excell 15
Chevron Rando HDZ 15
OPERATING
GATE
WITHOUT
BATTERIES
If the liftgate needs to be operated before the batteries
are installed, temporary battery and battery charger can
be used.
BATTERY
CHARGER
Note! Never operate liftgate only with battery charger,
this can cause damage to electrical parts.
LIFTGATE
BATTERY
GR01091
Chapter
4
Liftgate
Installation
GR03015
BREATHER PLUG
Check to make sure the breather plug is installed.
Should be factory installed. Check oil level.
Replace transport plug from oil tank with breather plug.
Check oil level, oil level should be ½” below top of oil
tank.
Add oil if needed.
Do not over fill.

18
Cable lead-through
In order to be able to install/remove/adjust the cables in the
cable grommet, its protective cover must be removed and
the five screws loosened.
Remove the protective cover fastened with three screws
on the cable grommet.
Loosen the five screws on the cable grommet. Cables
can now be installed/removed/adjusted in the grommet.
On installation, the cable must be installed together with
existing cabling with cable ties. Ensure the length of the
cable is sufficient for moving the control card. The outer
sheathing on cable connected to the control card must
be stripped 10 inches.
GR03025
Once all the cables are in their appropriate places in the
grommet, retighten the five screws.
Install the protective cover on the cable grommet with
the three corresponding screws.
––––
Chapter
4
Liftgate
Installation

Chapter 4
Liftgate Installation
19
Connecting the Controllers
Install the main control unit (CD1) at a suitable place, but the position of the control unit
should ensure that the operator has a good view of the load, the working area and the
loading area,while maintaining a safe distance from the risk zone between the platform and
the body.
All control units should be connected to the correct terminals on the control card. Avoid
running two control units in parallel to each other. If you do, if one control unit fails it will
shut down any others running in parallel to it.
Connecting controller
The most commonly occurring controller (CD Control Device) models shown below. Possible controller models vary
depending on lift model, configuration and relevant market.

Chapter 4 Liftgate Installation
INSTALLATION OF POWER CABLE AND OPTIONAL IN CAB SWITCH
In the next section we will take you through installation of the Control Switch, In Cab Switch if supplied and powering
the liftgate to the batteries.
As part of the liftgate you will find a Grey insulated cable
that has an orange and black wire. This is used for wiring
the In Cab Switch. Run the grey insulated wire for the In
Cab Switch down the chassis frame.
Install the In Cab switch and open platform light to the
dash.
The black wire runs to the center post of the switch
Run a ground from the Bronze post of the switch to any
ground point near the dash
Connect a wire to the silver post and connect other end to
+12VDC fused power aux source in the cab
If you are not running an in cab switch you will need to
follow the instruction for accessing the relay card to install
a jumper between CS and CS+ as shown in the diagram.
If not installing In Cab
Switch install a
Jumper between CS
and CS+
Protect wires from any sharp edges or holes
that may abrade insulated covering of wires.
Secure wire so it does not come near, or in
contact with, other vehicle wiring, fuel lines,
brake lines, air hoses, exhaust system, etc.
20