TrailMax 8012DT User manual

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Table of Contents
Section 1. Operation .................................................................................... 3
1.0 Introduction ................................................................................... 3
1.1 Purpose ........................................................................................ 3
1.2 Rating............................................................................................ 3
1.3 Design and Safety Factors ........................................................... 4
1.4 Vehicle Load and Handling Limits ................................................ 4
1.5 Reporting Safety Defects ............................................................. 7
1.6 Alert Symbols ................................................................................ 8
1.7 Pre-Trip Inspection........................................................................ 9
1.8 Hook-Up Procedures .................................................................. 10
1.9 Loading and Unloading .............................................................. 11
Trailers With Ramps ................................................................. 12
Trailers With Tilt Decks ............................................................. 12
Section 2. Maintenance .............................................................................. 13
2.0 Periodic Maintenance ................................................................. 13
2.1 Structural Components ............................................................... 14
Sub-Frame ................................................................................ 14
Deck .......................................................................................... 14
2.2 Sub-Assembly Components ....................................................... 14
Coupling ................................................................................... 14
Jack .......................................................................................... 15
Cushion Cylinder ...................................................................... 15
Deck Latch ................................................................................ 15
Deck Hinge Assembly ............................................................... 15
2.3 Running Gear ............................................................................. 16
Suspension ............................................................................... 16
Hubs and Drums ....................................................................... 16
Brake Drum Inspection ............................................................. 17
Bearing Inspection .................................................................... 17
Standard Bearing Lubrication ................................................... 18
E-Z Lube Bearing Lubrication .................................................. 18
Seal Inspection and Replacement ........................................... 19
Hub Reinstallation and Bearing Adjustment ............................ 19
2.4 Wheels and Tires ........................................................................ 20
Wheels ..................................................................................... 20
Tires .......................................................................................... 22
Inflation Pressure ..................................................................... 22
Tire Wear Diagnostic Chart ...................................................... 23
2.5 Electrical ..................................................................................... 24
Harnesses and Lights............................................................... 24
Junction Block .......................................................................... 24
Electrical Plug ........................................................................... 24
2.6 Brake System (Common to Hydraulic and Electric) .......................... 25
Contents
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Brake Adjustment ...................................................................... 25
Brake Cleaning and Inspection ................................................. 26
Brake Lubrication ...................................................................... 26
2.7 Hydraulic Brake System .............................................................. 27
Operation .................................................................................. 27
Surge Actuator Maintenance ..................................................... 27
Corrosive Environment Warning ............................................... 28
Hydraulic Lines.......................................................................... 28
Hydraulic Brakes ....................................................................... 28
Brake System Bleeding ............................................................ 29
Hydraulic Brake System Troubleshooting Chart ....................... 31
2.8 Electric Brake System ................................................................ 31
Operation .................................................................................. 31
Using your Brakes Properly ...................................................... 32
Synchronization ........................................................................ 33
Controllers ................................................................................ 33
Magnets .................................................................................... 34
Electric Brake System Troubleshooting .................................... 35
Measuring Voltage ..................................................................... 35
Measuring Amperage ................................................................ 37
Electric Brake System Troubleshooting Chart .......................... 38
2.9 Pre-Storage Maintenance ............................................................ 40
2.10 Pre-Season Maintenance ............................................................ 41
Section 3. Parts .......................................................................................... 42
3.1 Structural Components ............................................................... 42
3.2 Major Sub-Assemblies ................................................................ 45
Binkley Jack .............................................................................. 45
Couplers ................................................................................... 46
3.3 Running Gear .............................................................................. 48
Hydraulic Brake Components ................................................... 50
Electric Brake Components, 7K ............................................... 52
Axle End Components .............................................................. 54
3.4 Wheels and Tires ........................................................................ 55
3.5 Electrical ..................................................................................... 56
Harnesses and Lights ............................................................... 56
Electrical Plug ........................................................................... 58
Electric Brake Wiring ................................................................ 59
Electric Breakaway System ...................................................... 59
3.6 Hydraulic System ........................................................................ 60
Hydraulic Lines.......................................................................... 60
Model DA20 Surge Actuator ...................................................... 62
Power Unit Motor....................................................................... 64
Power Unit Control Valve........................................................... 66
Power Unit Control Valve Schematic ........................................ 67
Gear Pump and Manifold Assembly Parts List .......................... 68
Gear Pump and Manifold Assembly Parts Illustration ............... 69
3.7 Tool Box ....................................................................................... 70
Section 4. Warranty Claim Procedure ....................................................... 72
Contents

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Section 1. Operation
1.0 Introduction
This section describes how trailers can have different operational characteristics
based on design, load configuration, gross weights, suspension characteristics, articu-
lation and extreme differences between loaded and unloaded weights.
Trailers have safe operating limits just as automobiles, airplanes, and other ve-
hicles. The interaction of the vehicle characteristics, maintenance, load, roadway,
weather, the skill of the driver and vehicle speed affect these limits. Knowledge of how
these factors affect the vehicle’s operating limits and utilization of defensive driving
techniques should result in safer driving.
1.1 Purpose
The purpose of this section is to describe how the vehicle characteristics, mainte-
nance, road conditions, and weather can affect trailer control and stability limits, and
how driver awareness and skill can help compensate for these factors. This knowledge
will assist you to safely enjoy the maximum utility and productivity from your trailer.
First and foremost, DO NOT operate the trailer until you have read and fully under-
stand this instruction and operating manual. It is also important that each and every
person who operates the trailer be given the opportunity to read this manual.
1.2 Rating
Gross Axle Weight Rating (GAWR) is the rated load-carrying capacity of an indi-
vidual axle and wheel assembly. It represents the load that may be steadily sustained
by the components in the system; i.e., tires, wheels, hubs, bearings, axles, brakes,
suspension, sub-frame, etc. with the GAWR limited by the component with the lowest
working rating. Consideration of environmental and operational factors may require the
manufacturer to reduce the nominal rating.
Gross Vehicle Weight Rating (GVWR) is the maximum rated combined weight of a
trailer and its payload (uniformly distributed) based on its structural capabilities.
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1.3 Design and Safety Factors
The safety factor is a ratio between the design stress imposed by the load sitting
static on the trailer and the minimum yield stress of the steel used in construction of
that trailer structure. For example, if the structure is built using 50,000 psi minimum
yield strength steel and the load sitting on it causes a stress level of 25,000 psi then a
2:1 safety factor would exist. THIS SAFETY FACTOR DOES NOT MEAN THAT THE
STRUCTURE CAN THEN BE USED TO CARRY TWICE THE RATED LOAD. Under
dynamic conditions, or as the trailer moves and encounters shocks, vibrations, twists
and other conditions that exist during transport, stress levels are elevated far beyond
those in the static situation.
Distributed Load is when a load is distributed evenly over the length of the trailer
deck. This would be considered as the ideal load scenario when fully loaded to rated
capacity.
Concentrated Load is one that is localized over a shorter than normal distance and
imposes greater stress in the concentrated load areas. Under these conditions, it is not
recommended to carry the full rated capacity of the trailer. Extreme concentrated appli-
cations may require additional support for the load.
1.4 Vehicle Load and Handling Limits
Vehicle handling limits can be greatly affected by the weight of a load, its place-
ment, the amount of weight distributed over the axles and whether or not the load is
secured properly.
Tow vehicle and trailer combinations are designed to provide maximum directional
control and roll stability within the constraints of highway size and weight limits. Any
combination can be rolled over by driving too fast around a curve, making too abrupt a
maneuver, or by leaving the roadway. Locking up the wheels on an axle can result in a
jackknife or trailer swing out.
One of the major contributing factors to vehicle rollover is high center of gravity on
tall loads. Extreme caution should be used in maneuvering a vehicle and trailer combi-
nation, or any unit that has a tall load. Positioning the load in a central side to side
location will enhance directional control, roll stability and braking.
You should be aware that trailers with a shorter wheel base are more prone to roll
during an abrupt lane change or quick reactions at the wheel. This tendency can be
made dramatically worse with a tall, high center of gravity load.
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Overloading a vehicle should never be permitted. Overloading results in tire blow-
outs, spring breakage, frame damage, diminished braking capacity, and will severely
alter the vehicle’s normal handling characteristics. All vehicles are designed with a
maximum load capability. To best utilize these vehicles in the safest manner the loads
as shown on the certificate label should not be exceeded.
Adequate tongue weight is required for trailers to tow correctly. Inadequate tongue
weight can cause a “whipping action” particularly in shorter wheel base trailers. Too
much tongue weight can overload tow vehicle hitch resulting in reduced steering load
and loss of steering control. Selecting the correct tow vehicle is crucial for the applica-
tion.
Always maintain enough braking and stopping distance. Erratic or unequal brake
action from side to side on either tow vehicle or trailer can cause handling problems in
braking situations. A balance between tow vehicle and trailer on brake application and
release timing and synchronized pressure will reduce push/pull characteristics which
when excessive, may result in jackknife. The use of properly matched brake lining is
recommended to enhance safer braking.
Proper alignment of both tow vehicle and trailer wheels will add significantly to the
handling characteristics of the combination and allow the driver to utilize all the design
responses of the vehicle to make evasive maneuvers in the safest manner.
Irregular terrain, steep grades and crowned roads, especially rural roadways, free-
ways, exit ramps, curves, bumps and depressions introduce forces into a tow vehicle/
trailer combination that could result in an accident if proper precautions and driving
techniques are not followed. Even a vehicle that meets all maintenance and load re-
quirements can become hazardous when excessive speeds and certain roadway char-
acteristics are combined.
While on a downgrade, the force of gravity works against the driver in maintaining
control of the vehicle, particularly if the road surface is wet or slick from snow and ice
or loose material. On upgrades, the problem is spinning out due to insufficient traction
at the drive wheels, particularly on snow and ice.
Great care must be taken to avoid excessive use of brakes on long downgrades.
Overheated brakes are dangerously inefficient. It is very dangerous to brake on a
downgrade using only the trailer brakes. If this is done, the trailer brakes heat up and
fade and the tow vehicle brakes alone will not be able to stop the combination by
themselves. Drivers should reduce speed, downshift and use engine compression as
the principal means of controlling speed on long grades and using all brakes so brake
temperatures can be held to a safe level.
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Operation
Weather conditions can be a major factor in the cause of accidents. Rain, ice, snow,
high winds and visibility combined with excessive speed, sudden lane changes, or
other factors that put lateral forces into a tow vehicle trailer combination contribute
significantly to an accident.
Slippery roads can increase stopping distances and reduce the ability to control the
vehicle. When the road is wet, the available tire/road friction may be half that of a dry
road, and icy roads can reduce friction many times over wet roads. If hard braking or
rapid acceleration occurs, there may be little or no friction available to prevent tire
lateral movement and skidding results.
The driver has a responsibility to compensate for the characteristics and conditions
of his vehicle, the road conditions and weather. Reducing speeds and increasing atten-
tiveness may compensate for most of these conditions. The more familiar the driver is
with the vehicle and the road, the less likely he will need to make abrupt emergency
maneuvers which will take the vehicle to its limits. Control and stability may be main-
tained if the driver knows his vehicle, his load, and the road.
Either braking or accelerating while cornering can significantly reduce the control-
lability and stability of the vehicle and should be avoided. The best driving practice is to
decelerate to a safe conservative speed before entering a corner or approaching con-
gested traffic and then apply only moderate power until an essentially straight path has
been established.
It is imperative that a safe speed always be maintained. The safe speed is that
speed at which control can be maintained over the vehicle at all times. This speed will
allow an emergency change of lane maneuver, travel off an exit ramp with a tightening
radius and recovery from pavement drop-off or wet pavement. This speed will vary from
one combination of vehicle to another and takes into consideration such factors as
road conditions, weather, traffic, visibility, type of load and experience of the driver.

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1.5 Reporting Safety Defects
If you believe that your vehicle has a defect that could cause a crash, injury, or death,
you should immediately inform the National Highway Traffic Safety Administration (NHTSA)
in addition to notifying Gem State Mfg., Inc.
If NHTSA receives similar complaints it may open an investigation, and if it finds that a
safety defect exists in a group of vehicles it may pursue a remedy campaign and recall
those vehicles. However, NHTSA cannot become involved in individual problems between
you, your dealer, or Gem State Mfg., Inc.
To contact NHTSA, you may either call the Vehicle Safety Hotline toll free at 1-888-327-
4236 (TTY: 1-800-424-9153), go to http://www.safecar.gov; or write to Administrator,
NHTSA, 400 Seventh Street SW., Washington, DC 20590. You can also obtain other
information about motor vehicle safety from http://www.safecar.gov.
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Operation
1.6 Alert Symbols
It is important that your know the meaning of the following symbols that are used
throughout this document.
SAFETY ALERT!
This is the safety alert symbol. It is used to alert you to potential per-
sonal injury hazards. Obey all safety messages that follow this symbol to
avoid possible injury or death.
DANGER!
DANGER! indicates an imminently hazardous situation which, if not
avoided, will result in death or serious injury.
WARNING!
WARNING indicates a potentially hazardous situation which, if not
avoided, could result in death or serious injury.
CAUTION!
CAUTION indicates a potentially hazardous situation which, if not
avoided, may result in minor or moderate injury.
CAUTION
CAUTION used without the safety alert symbol indicates a potentially
hazardous situation which, if not avoided, may result in property damage.
!
DANGER
!
WARNING
!
CAUTION
!
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1.7 Pre-Trip Inspection
There are some items on every vehicle combination that can be and should be
inspected prior to every trip that require no special knowledge, training, or sophisti-
cated equipment.
Before beginning a trip, make a thorough visual inspection of the trailer for cracks
in the structure, or bent components such as the tongue or frame. Check for any miss-
ing fasteners in suspension as well as other areas, and look for broken or bent springs
and spring hangers or otherwise damaged components.
Verify that the hitch on the tow vehicle is the correct size and configuration to fit the
trailer coupling. The hitch must be rated to meet or exceed the Gross Vehicle Weight
Rating (GVWR) of the trailer.
Check the hitch height of the trailer and compare it to the tow vehicle; it is very
important that the trailer be towed in the level position when loaded. In order to achieve
the correct hitch height, elevate the tongue of the trailer slightly (1" to 2") by adjusting
the trailer hitch to compensate for settling of tow vehicle springs when loaded.
Always visually inspect hitch for unusual appearances such as bent components,
cracks in welds or chipped paint where stress cracks may appear from high loads.
Check tires for proper inflation. Tire manufacturers recommend checking inflation
pressure while trailer is not loaded and tires are cool. This will provide a more accurate
reading. A drop of 10 PSI in tire pressure can reduce the carrying capacity of the tire as
much as 20%. This reduced capacity could cause tire failure and poor tire life.
Maintaining proper wheel nut torque value is essential to prevent wheel end sepa-
ration or potential damage to the hub or wheel. Always check wheel nuts every 50 to
100 miles for the first 200 miles of operation, then periodically thereafter. The same
procedure should be repeated after dismount and remount of wheels. It is important to
follow the specified tightening sequence recommended in the tire maintenance section
of this manual.
NOTE: For trailers with hydraulic surge brakes, check the brake fluid reservoir
level and add brake fluid to the fill line if necessary.
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1.8 Hook-Up Procedures
TRAILER HOOK-UP
The consequences of not properly hooking the trailer to the tow vehicle
can be very serious. Failure to adhere to information in this section could
lead to the trailer becoming detached, the trailer brakes and/or lights not
working correctly, or other unsafe situations which could result in an acci-
dent causing property damage, bodily injury or death.
Connect the tow vehicle to the trailer and check that the coupler is completely latched.
Be sure that a safety pin is inserted to ensure coupler will not unlatch during transport.
Connect the electrical plug from the trailer’s harness to the receptacle of the tow ve-
hicle. Check all lights on the trailer to make sure they are working correctly with the tow
vehicle’s electrical system.
Be sure the landing leg and drop foot are fully retracted and the crank handle is
stowed in transport position. For trailers with 2-speed jacks, use low gear for raising
and lower the jack under load, and high gear for raising and lowering the leg when it is
off the ground.
Check all safety chains and their attachment to both the trailer and the towing ve-
hicle. Connect safety chains to tow vehicle using crossed pattern under tongue. Allow
slack for turning, but avoid having chains drag on pavement. Make certain that all
attachment devices are properly installed and in good working order.
For trailers with air brakes, connect the Glad Hands (one service and one emer-
gency) to tow vehicle. Shut off petcock(s) on air tank(s) or if already shut, open to
exhaust all moisture, then shut off. It is very important that the air system be drained of
moisture after each use to keep all components functioning properly and to make equip-
ment safe.
Trailers with electric brakes or hydraulic surge brakes come equipped with an emer-
gency breakaway device. The breakaway system is designed to operate after the cou-
pling system has failed. Connect breakaway chain S-hook to bumper or hitch on tow
vehicle. Allow slack for turning, but avoid letting chain drag on pavement. Provide as
straight a connection as possible.
Always check that trailer brakes are working properly. If trailer is equipped with electric
brakes, use brake controller to adjust for load.
The breakaway system is for emergencies and is not a parking brake.
The following paragraphs pertain to trailers with hydraulic surge brakes:
Operation
WARNING
!