Demco CR 33.5 User manual

8C010267, Rev AB
7/10/18
SIDE DUMP
CONVERTER DOLLY
CR 33.5 Converter Dolly Tongue
CR 78 Converter Dolly Tongue
CR 108 Converter Dolly Tongue
CR 120 Converter Dolly Tongue
CR 133 Converter Dolly Tongue
SS-102-4LS Converter Dolly
8C010246, Rev. AB
12-10-2018

2
Table of Contents
Introduction........................................................................................................................... 4
Dealer Checklist.................................................................................................................... 6
To The Owner........................................................................................................................ 7
Safety.................................................................................................................................... 8
Torque Requirements............................................................................................................ 12-13
Safety Decals........................................................................................................................ 14-15
Coupling/Uncoupling............................................................................................................. 15-21
Operating Instructions........................................................................................................... 22
Pre-Trip Checklist.................................................................................................................. 23
Maintenance Check List........................................................................................................ 24-26
Full Function Anti-lock Brake System................................................................................... 27-28
Haldex Brake System Troubleshooting Guide...................................................................... 29-35
Adjustment and Operation of Brakes.................................................................................... 36-37
Tires...................................................................................................................................... 38
Wheels Installation................................................................................................................ 39
Wheel Maintenance During Tire Inspection.......................................................................... 40
Axle Inspection...................................................................................................................... 41
Suspensions......................................................................................................................... 42
Suspension Torque Specication.......................................................................................... 43
Troubleshooting Electrical System........................................................................................ 44
Troubleshooting General....................................................................................................... 45-49
Parts
SS-102-4LS, Tandem Spring Ride Converter Dolly.............................................................. 50-55
Converter Dolly Tongue 33-1/2”............................................................................................ 56-59
Converter Dolly Tongue 78”.................................................................................................. 60-63
Converter Dolly Tongue 108”................................................................................................ 64-67
Converter Dolly Tongue 120”................................................................................................ 68-71
Converter Dolly Tongue 133”................................................................................................ 72-75
ABS Brake Parts................................................................................................................... 76
Hutch Suspension Kit............................................................................................................ 77-78
7700/9700 4-Spring Maintenance......................................................................................... 79-83
Hub Pilot Axles...................................................................................................................... 84-104

3
In this document you will nd information based on available knowledge
at the time of its publication. To be accurate with the information, every
effort was made but may not cover all details or variations of a trailer or
provide every possibility in connection with its production, operation and
maintenance. A Feature and Option may be presented in the manual that
is not relevant to this trailer. Demco assumes no obligation of notice, to
holders of this document, with changes made to a product.
SPECIFICATIONS AND DESIGN ARE SUBJECT TO CHANGE WITHOUT NOTICE.
Demco is often making improvements and developing new designs. In
doing so, we reserve the right to make changes and/or improvements
without obligation for equipment sold beforehand. Self-modication to our
trailers may affect the operation, function, and safety, so this is not advised.
If a replacement part is necessary, Demco should supply it, please contact
your nearest dealer or Demco.
DEMCO STATEMENT OF PRODUCT SAFETY:
As a producer of agricultural and transportation equipment, Demco is fully
aware of its responsibility of providing its customers products that perform
their expected use, in a truly safe manner. Safety considerations shall be a
fundamental and high precedence part of all engineering/design analysis
and judgments involving Demco products. It is our stated policy that
our products will be manufactured to coincide with the safety standards
specied by the National Association of Trailer Manufacturers and/or any
other ofcially recognized standards at the time manufactured. However,
this statement should not be translated to mean that our product will
uphold against a customer’s own carelessness or disregard for common
safety practices specied in each product’s manual, nor will we be
accountable for any such occurrence.
Product Disclaimer

4
PLEASE NOTE:
• All documents within the manual referring to products not manufactured by Demco
have been printed with the permission of the manufacturer specied.
• All references to driver, passenger, front and rear of the trailer are determined from a
position behind the trailer and facing forward.
Introduction
GENERAL INFORMATION:
Demco requires that you and anyone else who will be operating and maintaining the trailer
read and understand the guidelines in the manual for safe, efcient, and trouble free
operations. Proper maintenance, adjustments and use will result in many years of service.
Keep this manual handy for frequent reference and to pass on to new operators or owners. If
assistance, information, or additional copies of the manual are needed, contact the nearest
dealer, a distributor, or Demco.
At Demco we strive to design, produce and deliver the highest quality trailer on the market.
Our employees have a strong background of knowledge and combined experience in
manufacturing to put quality workmanship into our products. In this manual you will nd
information covering all models of the Demco Side Dump Trailer line. Use the table of
contents to locate specic areas of interest.

5
Introduction
MODEL NO.__________________________
SERIAL NO.__________________________
DATE PURCHASED___________________
Serial Number
Example: VIN Number Description
57C
Demco
Side Dump
40’ Length
No. of Axles
Model Year Demco
Demco Indentier Number
Trailer Sequence
Check Digit
40
KS 29CT 627 045
For your convenience we have four easy ways to register your warranty.
• Call our toll free number and ask for warranty
registration. 1-888-274-6010
• Fax completed warranty registration form.
Fax: [phone]
• Register on-line in warranty page at
www.demco-products.com
• Complete and return registration form.
Demco Warranty does not cover the following:
1) Cleaning, transporting, mailing and service call charges.
2) Depreciation or damage caused by normal wear, accidents,
improper protection or improper use.
See complete Warranty for details.
In addition to the VIN number Demco has
placed a coded unit number on the chassis
and the tub. Call Demco for location.
Record your trailer model and serial number in the space provided below.
Your dealer needs this information to give you prompt, efcient service
when you order parts.

6
1. All hardware properly tightened
2. Proper 5th wheel t
3. Lubrication of grease ttings
4. Lug nuts are tight
5. All decals properly located and readable
6. Lights function properly
7. Air lines tight and no pinched lines
8. Brakes functioning properly
9. Overall condition (touch up any scratches, clean and polish)
10.Operator’s manual
Date Delivered: _____________
Signature of Salesman or Technician:________________________________
PRE-DELIVERY CHECKLIST
Dealer Checklist
To The Dealer:
Inspect the trailer thoroughly after shipment to be certain it is functioning properly
before delivering it to the customer. The following checklist is a reminder of
points to cover. Check off each item as it is found satisfactory or after proper
adjustment is made.
DELIVERY
Review the operator’s manual with the customer. Explain the following:
1. Safe operation and service
2. Correct trailer operation
3. Daily and periodic lubrication and maintenance
4 Daily and periodic inspections
5. Trouble shooting
6. Storing trailer
7. Demco parts and service policies
8. Have the customer write the trailer model and serial
number in space provided in manual introduction.
9. Give customer the operator’s manual and encourage
the customer to read the manual carefully.
10.Completion and mailing of warranty registration form.
Date Delivered:_________________________
Signature:_____________________________
Model No:_____________________________
Serial No:______________________________

7
To The Owner
Thank you for your recent purchase of a new Demco Side Dump
Trailer. The primary objective of Demco is to build and provide you
with a quality product. However, in the event that a problem
does occur, it is imperative that your warranty registration
is on file in order to accurately respond to your specic service
circumstances. For your convenience we have four easy ways to
register your warranty:
•Call our toll free number and ask for
warranty registration.
1-888-274-6010
•Fax your completed warranty
registration form.
1-712-262-1022
•Register on-line at:
www.demco-products.com
•Complete and mail the warranty
registration form.
This manual has been prepared to assist you in the operation of
your new trailer and contains information pertaining to safety,
operations and all of its parts. Our personnel in sales and service
are always available to assist you when questions arise concerning
the maintenance or operations of your trailer.
When ordering parts, please refer to part numbers and
descriptions as listed throughout this book. All parts and whole
goods will be shipped FOB Spencer, IA. Or FOB your regional
distributor. Always check merchandise immediately upon receipt
for damage or shortage. Note any discrepancy on carrier’s bill of
lading and notify Sender within 10 days. Returned goods will be
subject to a 15% restocking charge. Demco reserves the right to
make improvements and modications on equipment without
obligation to change previously built equipment. All prices are
subject to change without notice.
Register
Warranty
One of
Four Ways

8
Safety
RECOGNIZE SAFETY INFORMATION
• This is the safety-alert symbol. When you see his symbol
on your machine or in this manual, be alert to the
potential for personal injury. Follow recommended
precautions and safe operating practices.
FOLLOW SAFETY INSTRUCTIONS
• Carefully read all safety messages in this manual and on your
machine safety signs. Keep safety signs in good condition.
Replace missing or damaged safety sign.
• Learn how to operate the machine and how to use
controls properly.
• Do not let anyone operate without instruction.
• Keep your machine in proper working condition.
• Unauthorized modication to the machine may
impair the function and\or safety and affect machine life
PROTECT CHILDREN AND BYSTANDERS
• Before you back, LOOK CAREFULLY behind for
children.
• Clear area of children, pets and bystanders.
HIGHWAY AND TRANSPORT OPERATIONS
Adopt safe driving practices:
• Always drive at a safe speed relative to local
conditions and ensure that your speed is low enough
for a emergency stop to be safe and secure. Keep
speed to a minimum.
• Reduce speed prior to turns to avoid the risk of
overturning.
• Avoid sudden uphill turns on steep slopes.
• Always keep the tractor or towing vehicle in
gear to provide engine braking when going downhill.
Do not coast.
• Do not drink and drive.
• Comply with state and local laws governing highway
safety and movement of equipment on public roads.
• Use approved accessory lighting and necessary
warning devices to protect operators of other vehicles
on the highway during daylight and nighttime transport.

9
Safety
HIGHWAY AND TRANSPORT OPERATIONS
• Plan your route to avoid heavy trafc.
• Be a safe and courteous driver. Always yield to
oncoming
trafc in all situations, including narrow bridges,
intersection, etc.
• Be observant of bridge loading ratings. Do not cross
bridges rated lower than the gross weight at which
you are operating.
• Always operate the tractor trailer in a position to provide
maximum visibility at all times. Make allowances for
increased length and weight of the equipment when
making turns, stopping the unit, etc.
AVOID HIGH PRESSURE FLUIDS
• Escaping uid under pressure can penetrate the
skin causing serious injury.
• Avoid the hazard by relieving pressure before
disconnecting hydraulic or other lines. Tighten
all connections before applying pressure.
• Search for leaks with a piece of cardboard.
• Protect hands and body from high pressure uids.
• If an accident occurs, see a doctor immediately.
DISPOSE OF FLUIDS PROPERLY
• Improperly disposing of uids can harm the
environment and ecology. Before draining any
uids, contact your local environmental agency
for the proper waste disposal methods.
• Use proper container when draining uids. Do
not use food or beverage containers that may
mislead someone into drinking from them.
• DO NOT pour oil into the ground, down a drain, or
into a stream, pond, or lake. Observe relevant
environmental protection regulations when disposing
of oil and other harmful waste.

10
TAKE NOTE! THIS SAFETY ALERT SYMBOL FOUND THROUGHOUT THIS MANUAL IS USED
TO CALL YOUR ATTENTION TO INSTRUCTIONS INVOLVING YOUR PERSONAL SAFETY AND
SAFETY OF OTHERS. FAILURE TO FOLLOW THESE INSTRUCTIONS CAN RESULT IN INJURY
OR DEATH!
THIS SYMBOL MEANS:
ATTENTION!
BECOME ALERT!
YOUR SAFETY IS INVOLVED!
SIGNAL WORDS
Note use of following signal words DANGER, WARNING, and CAUTION with safety messages. The
appropriate signal word for each has been selected using the following guidelines:
DANGER: Indicates an imminently hazardous situation that, if not avoided, will result in death or serious
injury. This signal word is to be limited to most extreme situations typically for machine components
which, for functional purposes, cannot be guarded.
WARNING: Indicates a potentially hazardous situation that, if not avoided, could result in death or
serious injury, and includes hazards that are exposed when guards are removed. It may also be used
to alert against unsafe practices.
CAUTION: Indicates a potentially hazardous situation that, if not avoided, may result in minor or
moderate injury. It may also be used to alert against unsafe practices.
EQUIPMENT SAFETY GUIDELINES
Every year many accidents occur which could have been avoided by a few seconds of thought and a
more careful approach to handling equipment. You, the operator, can avoid many accidents by observing
the following precautions in this section. To avoid personal injury, study the following precautions and
insist those working with you, or you yourself, follow them.
Operator should be a responsible adult. DO NOT ALLOW PERSONS TO OPERATE THIS UNIT UNTIL
THEY HAVE DEVELOPED A THOROUGH UNDERSTANDING OF SAFETY PRECAUTIONS AND
HOW IT WORKS.
DO NOT modify the trailer in anyway. Doing so may impair the function and/or safety and could affect
the life of the trailer.
Never exceed the maximum capacity of the trailer. By doing so you risk damage to your Demco trailer.
If it’s ability to do a job, or to do so safely is in question DON’T TRY IT.
Review safety instructions with all users annually.
Replace any caution, warning, danger or instruction safety decal that is not readable or is missing.
Location of such decals is indicated in this booklet.
Do not paint over, remove, or deface any safety signs or warning decals on your equipment. Observe
all safety signs and practice instructions on them.
Safety

11
Safety
TIRE AND LUG NUT SAFETY
It is essential to inspect the trailer tires and wheels before each tow. Trailer tires are more likely to fail
compared to car tires due to the heavier load the trailer carries. Please follow the list of guidelines and/
or possibilities below that could cause serious injury or even death.
♦ Replace the tire before towing if the tire has a bald spot, cut, bulge, is showing any cords, or
is cracked.
♦ If uneven tread is noticed, take the trailer to a dealer service center for an inspection. Tire
imbalance, axle misalignment, or incorrect ination could cause the uneven tread.
♦ To little of tread will not be adequate enough for traction and can cause loss of control on wet
highways.
♦ Tire pressure that is improper causes an unstable trailer and could blowout the tire causing
loss of control.
♦ Check the tire pressure before towing, while the tire is cold. For the recommended PSI, see
the VIN Plate or the side wall of the tire.
♦ Always order and install tires and wheels with appropriate type and load capacity to meet or
exceed gross weight of unit.
The inspection of the tire and wheel lug nuts is necessary since they are prone to loosen after rst
being assembled. Please follow the list of guidelines and/or possibilities below that could cause serious
injury or even death.
♦ When towing a new trailer, check the lug nuts after the rst 50 to 100 miles of driving.
♦ Metal creep between the wheel and the lug nuts will cause wheel to loosen and could come
off. Check to make sure the lug nuts are tight before each tow.
♦ Improper torque could cause the wheel to separate from trailer. A torque wrench should be
used to tighten the lugs nuts. If one is not available use a lug wrench then take to a trailer
dealer or service garage to tighten them to the required torque.
LOAD DISTRIBUTION SAFETY
The total weight of the load you put on the trailer, plus the empty weight of the trailer itself, must not
exceed the trailer’s Gross Vehicle Weight Rating (GVWR). You must distribute the load on the trailer
such that the load on any tire or axle does not exceed the tire load rating or the Gross Axle Weight
Rating (GAWR). If you do not know the weight of you trailer you must weigh it at a commercial scale.
See your VIN Plate for proper ratings. Not following these guidelines could cause serious injury or
even death.

12
BOLT TORQUE, TORQUE DATA FOR STANDARD NUTS,
BOLTS, AND CAPSCREWS.
Tighten all bolts to torques specied in chart unless otherwise noted. Check tightness of bolts
periodically, using bolt chart as guide. Replace hardware with same grade bolt.
NOTE: Unless otherwise specied, high-strength Grade 5 hex bolts are used throughout
assembly of equipment.
Bolt Torque for Standard bolts *
GRADE 2 GRADE 5 GRADE 8
“A”lb-ft (N.m) lb-ft (N.m) lb-ft (N.m)
1/4”6 (8) 9 (12) 12 (16)
5/16”10 (13) 18 (25) 25 (35)
3/8”20 (27) 30 (40) 45 (60)
7/16”30 (40) 50 (70) 80 (110)
1/2”45 (60) 75 (100) 115 (155)
9/16”70 (95) 115 (155) 165 (220)
5/8”95 (130) 150 (200) 225 (300)
3/4”165 (225) 290 (390) 400 (540)
7/8”170 (230) 420 (570) 650 (880)
1”225 (300) 630 (850) 970 (1310)
Torque gures indicated are valid for
non-greased or non-oiled threads and
heads unless otherwise specified.
Therefore, do not grease or oil bolts or
capscrews unless otherwise specied
in this manual. When using locking
elements, increase torque values
by 5%.
* GRADE or CLASS value for bolts
and capscrews are identied by their
head markings.
Torque Specications
CLASS 8.8 CLASS 9.8 CLASS 10.9
“A”lb-ft (N.m) lb-ft (N.m) lb-ft (N.m)
6 9 (13) 10 (14) 13 (17)
7 15 (21) 18 (24) 21 (29)
8 23 (31) 25 (34) 31 (42)
10 45 (61) 50 (68) 61 (83)
12 78 (106) 88 (118) 106 (144)
14 125 (169) 140 (189) 170 (230)
16 194 (263) 216 (293) 263 (357)
18 268 (363) -- -- 364 (493)
20 378 (513) -- -- 515 (689)
22 516 (699) -- -- 702 (952)
24 654 (886) -- -- 890 (1206)
Bolt Torque for Metric bolts *
GRADE-2 GRADE-5 GRADE-8
8.8 10.9
9.8
CLASS 8.8 CLASS 9.8 CLASS 10.9

13
TORQUE REQUIREMENTS
1 1 1 1 1
2222 2
3
3
3
3
34
4
4
4
4
5
55
5
6
7
6
68
7
8
10
5 BOLT 6 BOLT 8 BOLT 10 BOLT
9
4 BOLT
It is extremely important to apply and maintain proper wheel mounting torque on your trailer axle.
Torque is a measure of the amount of tightening applied to a fastener (nut or bolt) and is expressed
as length times force. For example, a force of 90 pounds applied at the end of a wrench one foot long
will yield 90 lbs-ft of torque. Torque wrenches are the best method to assure the proper amount of
torque is being applied to a fastener.
NOTE: Wheel nuts or bolts must be applied and maintained at the proper torque
levels to prevent loose wheels, broken studs, and possible dangerous separation of
wheel from your axle.
Be sure to use only the fasteners matched to the cone angle of your wheel (usually 60 degrees or 90
degrees). The proper procedure for attaching your wheels is as follows:
1. Start all bolts or nuts by hand to prevent cross threading.
2. Tighten bolts or nuts in the following sequence.
3. The tightening of the fasteners should be done is stages. Following the recommended
sequence, tighten fasteners per wheel torque requirements diagram:
4. Wheel nuts or bolts should be torqued before rst road use and after
each wheel removal. Check and re-torque after the rst 50 miles and
again at 100 miles. Check periodically thereafter.
WHEEL AND RIM TORQUE REQUIREMENTS
Description Application Minimum Torque Maximum Torque
(lbs-ft) (lbs-ft)
1/2” Cone Nut 12” – 13” Wheel 50 65
14” – 15” Wheel 90 120
5/8” Cone Nut Flat Disc Wheel 175 225
3/4” Hex Nut Demountable
Ring Clamp 210 260
3/4” Spherical Nut Single Wheel 450 500
Inner Dual 450 500
1-1/2” Spherical Nut Outer Dual 450 500
5/8” Flange Nut Wheels 275 325

14
Important: Install new safety decals and reectors if the old decals and reectors are destroyed, lost,
painted over or cannot be read. When parts are replaced that have decals or reectors, make sure you
install a new decal with each new part.
Safety/Decal/Reectors
WARNING
!
SUSPENSION HAZARD
To prevent serious injury or death:
• Loose suspension fasteners and worn
parts may cause vehicle instability.
• Replace worn or broken parts immediately
• Tighten fasteners to requirements stated.
AP 2987
WARNING
AP 4281
• Torque lug nuts to
450-500 ft. lbs. every
3000 miles
!
WHEEL NUT TORQUE HAZARD
To prevent serious injury or death:
Emergency parking
brakes will not function
if chambers are caged,
deactivated or removed.
• Block all wheels.
AP 3673
DANGER
EMERGENCY PARKING
BRAKE HAZARD
!
To prevent serious
injury or death from
parts explosion:
• Spring brake chamber
must be caged or
deactivated before
servicing. AP 3671
DANGER
SPRING BRAKE
CHAMBER HAZARD
!
To prevent serious injury or death:
• Properly match wheels, studs,
brake drums and cap nuts.
EQUIPMENT HAZARD
DANGER
AP 3672
!
White Reectors
AP2914 (1) Decal, WARNING, High
Pressure Fluid
AP2987 (1) Decal, WARNING,
Suspension Hazard
2-3/4” x 6-1/4”
AP3506 (6) Reective Tape
Red/Silver
AP3671 (2) DANGER Spring Brake
Chamber Hazard
AP3672 (2) DANGER Equipment
Hazard
AP3673 (2) DANGER Emergency
Parking Brake
Hazard
AP4281 (1) Decal, WARNING,
Wheel Nut Torque,
AP4292 (1) Decal, Hutch Suspension
Torque Orange and Black
AP4495 (1) Decal, WARNING,
Holland 5th Wheel Hook-up
AP2914
AP2987 AP4292
AP4281
AP4495
AP3673
AP3672 AP3671
NOTE: New decals and reectors are
available from your dealer.

15
HOW TO APPLY SAFETY DECALS:
1. Be sure that the installation area is clean and dry.
2. Be sure temperature is above 50°F(10°C).
3. Decide on exact position before removing the backing paper.
4. Remove smallest portion of split backing paper.
5. Align decal over specied area and carefully press the small portion with the exposed sticky
backing in place.
6. Slowly peel back remaining paper and carefully smooth remaining portions of decal into
place.
7. Small air pockets can be pierced with a pin and smoothed out using a piece of decal backing
paper.
Safety/Decal/Reectors

16
Coupling and Uncoupling
Knowing how to couple and uncouple correctly is basic to safe
operation of combination vehicles. General coupling and uncoupling steps
are listed below. There are differences between different trucks, so learn the
details of coupling and uncoupling the truck (s) you will operate.
WARNING:
INCORRECT COUPLING AND UNCOUPLING CAN RESULT IN SERIOUS
INJURY OR DEATH.
Coupling Tractor-Semitrailers
Step 1. Inspect Fifth Wheel
• Check for damaged/missing parts.
• Check to see that mounting to tractor is secure, no cracks in
frame, etc.
• Be sure that the fth wheel plate is greased as required. Failure
to keep the fth wheel plate lubricated could cause steering
problems because of friction between the tractor and the trailer.
• Check if fth wheel is in proper position for coupling.
− Wheel tilted down towards rear of tractor.
− Jaws open.
− Safety unlocking handle in the automatic lock position.
• If you have a sliding fth wheel, make sure it is locked.
• Make sure the trailer kingpin is not bent or broken.
Step 2. Inspect Area and Chock Wheels
• Make sure area around the vehicle is clear.
• Be sure the trailer spring brakes are on.
Step 3. Position Tractor
• Pull the tractor directly in front of the trailer. (Never back under the
trailer at an angle, because you might push the trailer sideways
and break the landing gear.)
• Check position, using outside mirrors, by looking down both sides
of the trailer.
Step 4. Back Slowly
• Back until fth wheel just touches the trailer.
• Don’t hit the trailer.
Step 5. Secure Tractor
• Put on the parking brake.
• Put transmission in neutral.

17
Step 6. Check Trailer Height
• The trailer should be low enough that it is raised slightly by the
tractor when the tractor is backed under it. Raise or lower the
trailer as needed. (If trailer is too low, tractor may strike and
damage nose of trailer; if trailer is too high, it may not couple
correctly.)
• Check that the kingpin and fth wheel are aligned.
Step 7. Connect Air Lines to Trailer
• Check glad hand seals and connect tractor supply (emergency) air
line to trailer supply (emergency) glad hand.
• Check glad hand seals and connect tractor control (service) air
line to trailer control (service) glad hand.
• Make sure air lines are safely supported where they won’t be
crushed or caught while tractor is backing under the trailer.
Step 8. Supply Air to Trailer
• From cab, push in “air supply” knob or move tractor
protection valve control from the “emergency” to the “normal”
position to supply air to the trailer brake system.
• Wait until the air pressure is normal.
• Check brake system for crossed air lines.
• Shut engine off so you can hear the brakes.
• Apply and release trailer brakes, listen for sound of trailer
brakes being applied and released. You should hear the
brakes move when applied and air escape when the brakes
are released.
• Check air brake system pressure gauge for signs of major air
loss.
• When you are sure trailer brakes are working, start engine.
• Make sure air pressure is up to normal.
Step 9. Lock Trailer Brakes
• Pull out the “air supply” knob, or move the tractor protection valve
control from “normal” to “emergency.”
Step 10. Back Under Trailer
• Use lowest reverse gear.
• Back tractor slowly under trailer to avoid hitting the kingpin too
hard.
• Stop when the kingpin is locked into the fth wheel.
Coupling and Uncoupling

18
Step 11. Check Connection for Security
• Raise trailer landing gear slightly off ground.
• Pull tractor gently forward while the trailer brakes are still locked
onto the tractor.
Step 12. Connect Hydraulic Couplers to Trailer
• Connect hydraulic hoses to trailer remotes.
Step 13. Secure Vehicle
• Put transmission in neutral.
• Put parking brakes on.
• Shut off engine and take key with you so someone else won’t
move truck while you are under it.
• Make sure air and electrical lines will not hit any moving parts of
the vehicle.
Coupling and Uncoupling
WARNING: Hydraulic uid escaping under pressure can have
enough force to penetrate the skin. Hydraulic uid may also infect a
minor cut or opening in the skin. If injured by escaping uid, see
doctor at once. Serious infection or reaction can result if medical
treatment is not given immediately. Make sure all connections are tight
and that hoses and lines are in good condition before applying
pressure to the system. Relieve all pressure before disconnecting
the lines or performing other work on the hydraulic systems.
Attach
Hydraulic
Lines Here

19
Step 14. Inspection Coupling
• Use a ashlight if necessary.
• Make sure there is no space between upper and lower fth
wheel. If there is space, something is wrong (kingpin may be
on top of closed fth wheel jaws; trailer would come loose very
easily).
• Go under trailer and look into the back of the fth wheel. Make
sure the fth wheel jaws have closed around the shank of the
kingpin.
• Check that the locking lever is in the “lock” position.
• Check that the safety catch is in position over locking lever. (On
some fth wheels, the catch must be put in place by hand.)
• If the coupling isn’t right, don’t drive the coupled unit; get it xed.
Step 15. Connect the Electrical Cord and Check Air Lines
• Plug the electrical cord into the trailer and fasten the safety
catch.
• Check both air lines and electrical line for signs of damage.
• Make sure air and electrical lines will not hit any moving parts of
the vehicle.
Coupling and Uncoupling

20
Step 16. Raise Front Trailer Supports (Landing Gear)
• Use low gear range (if so equipped) to begin raising the landing
gear. Once free of weight, switch to the high gear range.
• Raise the landing gear all the way up. (Never drive with landing
gear only part way up as it may catch on railroad tracks or other
things.)
• After raising the landing gear, secure the crank handle safely.
• When full weight of trailer is resting on tractor:
Check for enough clearance between rear of tractor frame and landing
gear. (When tractor turns sharply, it must not hit landing gear.)
Check that there is enough clearance between the top of the tractor tires
and the nose of the trailer.
Uncoupling Tractor-Semitrailers
The following steps will help you to uncouple safely.
Step 1. Position Rig
• Make sure surface of parking area can support weight of trailer.
• Have tractor lined up with the trailer. (Pulling out at an angle can
damage landing gear.)
Step 2. Ease Pressure on Locking Jaws
• Shut off trailer air supply to lock trailer brakes.
• Ease pressure on fth wheel locking jaws by backing up gently (this will
help you release the fth wheel locking lever).
• Put parking brakes on while tractor is pushing against the kingpin. This
will hold rig with pressure off the locking jaws.
Step 3. Lower the Landing Gear
• If trailer is empty – lower the landing gear until it makes rm contact with
the ground, turn crank in low gear a few extra turns; this will lift some
weight off the tractor. (Do not lift trailer off the fth wheel.) This will:
- Make it easier to unlatch fth wheel;
- Make it easier to couple next time.
Coupling and Uncoupling