OPERATION MAINTENANCE SERVICE MANUAL
ELECTRICALLY CONTROLLED HYDRAULIC
BRAKE ACTUATION DEVICE
E/H 1000 & 1600 BRAKE ACTUATORS

www.dexteraxle.com

Table of Contents
Introduction.................................................................................. 1
Installation Instructions................................................................. 1
Electrical Wire Colors and Function................................................. 4
Electrical Installation Requirements............................................... 6
Test Electrical Operation................................................................ 7
Bleeding and Brake Adjustment...................................................... 8
Electric Controller Unit Testing/Adjusting..................................... 10
Troubleshooting Guide................................................................. 11
Dexter Axle Limited Warranty........................................................ 13
Dexter Video Gallery..................................................................... 16
Locations.................................................................................... 17

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CAUTION

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to potential injury hazards. Obey all safety messages
that follow this symbol to avoid possible injury or
death.

Scan QR code below for E/H Actuator Installation Video

E/H Actuator Installation

E/H 1000 & 1600 BRAKE ACTUATORS
OPERATION MAINTENANCE SERVICE MANUAL

Introduction

Before proceeding, make sure that the unit is appropriate for your particular brakes.
The E/H 1000 produces 1000 psi, typically used for duo-servo hydraulic drum
brakes, while the E/H 1600 produces 1600 psi for most hydraulic disc brakes. Please
refer to your brake manufacturer for proper operating pressures.
The Dexter E/H brake actuator is compatible with many electric brake controllers,
but the best performance will be achieved using an inertial type controller such as
the Dexter Predator DX2®. The electronic timer type of controller is not recommended
because these units use a fixed control that does not sense varying brake
requirements.

Installation Instructions
The following materials are required to properly install the Dexter E/H brake actuator.
If your trailer is not already equipped with brake lines, you will need enough ³⁄₁₆"
diameter automotive brake line to connect the trailer brakes to the unit. Where
possible, steel tubing is preferred.
•

Four ¹⁄₄" threaded fasteners to mount the unit to the trailer.

•

One quart of DOT 3, DOT 4, or DOT 5 brake fluid (from a new sealed
container).

•

One emergency breakaway kit - must include a 12 volt, 9 amp hour
(minimum) battery.

•

Wire (see Electrical Installation Requirements for proper
wire size).

Location of the Dexter E/H brake actuator is at the discretion of the vehicle owner.
When selecting the location, the following items should be considered:
1. The shorter the wiring between the unit and the electrical power source, the
smaller the voltage drop.
2. The unit should be located so that the electrical wiring and brake lines can be
neatly routed directly to the towing vehicle and trailer brakes. Special care should
be taken to minimize the number of bends and fittings in the brake line circuits.

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OPERATION MAINTENANCE SERVICE MANUAL

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INTRODUCTION / INSTALLATION INSTRUCTIONS

This manual has been provided to guide you through the process of installing,
operating, and maintaining your Dexter electrically controlled hydraulic brake
actuation device (also referred to as E/H brake actuator). This electrically powered
unit has been designed and manufactured to give safe, reliable power to your
hydraulic trailer brakes.

INSTALLATION INSTRUCTIONS

Installation Instructions
3. An emergency breakaway kit must be located on the trailer so that the trailer
breakaway cable can be easily attached to the towing vehicle.
4. The Dexter E/H brake actuator is powered from the electrical system on the
tow vehicle. In order for the unit to function properly, it must have adequate
electrical power (see Electrical Installation Requirements).
5. The Dexter E/H brake actuator should not be placed in an area where it is
susceptible to damage from trailer loads, road debris, or from being stepped
on. Failure to protect the actuator from damage can cause the unit to
malfunction and void the Dexter Axle warranty.
Mounting consideration should be given to the following:
1. The unit must be level, with the filler neck up.
2. It is the responsibility of the customer to provide necessary fasteners for
attachment of the actuator to the trailer.
3. Mount unit where it will not be submerged in water.
4. Mounting near the hitch is preferred. Do not mount near the trailer axles or
rear of the trailer.

CAUTION
The Dexter E/H brake actuator contains sensitive
electronics that must be protected. Drilling additional
holes in the housing, electrostatically painting, or
welding anywhere on the unit will damage the unit making
it inoperable and will void the manufacturer’s warranty.
Always remove the unit from the trailer before doing any
welding repair or modifications to the trailer structure.
Connect the trailer brake lines to the actuator as follows:
1. Remove the rubber or plastic plug from the ³⁄₁₆" inverted flare brake port.
2. Brake line must be compatible with DOT 3, DOT 4, or DOT 5 brake fluid.
3. Flush existing brake system and lines until thy are free of any contaminants
using DOT 3, DOT 4, or DOT 5 brake fluid prior to connecting to the Dexter E/H
brake actuator.
4. Connect the brake line from the trailer brakes to the ³⁄₁₆" inverted flare fitting
on the actuator. Do not tighten the ³⁄₁₆" brake line adapter more than the 22
Ft. Lbs. used at factory installation.
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OPERATION MAINTENANCE SERVICE MANUAL

Installation Instructions

CAUTION
Always use new DOT 3, DOT 4, or DOT 5 brake fluid
from a sealed container. Never attempt to reuse old or
dirty fluid. Do not overfill the unit. Take care to protect
painted surfaces from contact with the brake fluid.
Wash off any spilled brake fluid.
Mount the emergency breakaway switch and emergency breakaway battery on the
trailer, as detailed in the instruction sheets provided with the emergency breakaway kit.

Bolt Mounting Pattern

9-13/16"
(250mm)

2-1/2"
(63.5mm)

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INSTALLATION INSTRUCTIONS

Fill the unit with DOT 3, DOT 4, or DOT 5 brake fluid to the bottom of the reservoir filler
neck. When putting the filler cap back on it should be turned clockwise until snug.

CAUTION
Undersized wire will increase electrical resistance and
will prevent proper operation of this unit.
BLACK – 30 amp 12 volt supply from tow vehicle*
BLUE – Output from electronic brake controller in tow vehicle
WHITE – Trailer and tow vehicle ground
YELLOW – Cold side of breakaway switch

Electrical Schematic
Trailer
Plug
Blue
Black
White

+12 Volt 40 Amp
Circuit From
Tow Vehicle
Ground From
Tow Vehicle

Orange/Black
Charger
Minimum
9 Amp Hour
Breakaway
Battery

Blue

Black

BreakAway
Switch

White

WHITE

Lanyard

Light Blue/Yellow

From Tow
Vehicle Controller
(Typically Blue)

BLACK

ELECTRICAL INSTALLATION REQUIREMENTS

Electrical Wire Colors and Function

Hydraulic
Line

Yellow
Connect
To The
Trailer
Ground
Circuit

Note: Either an onboard or breakaway
battery may be used.

It is important that wire lengths for the BLACK power lead and WHITE ground lead be
no longer than 25 feet from the E/H brake actuator to the supply power (i.e. on board
trailer battery or the tow vehicle battery). The E/H brake actuator needs to be located
as close as possible to the battery near the front of the trailer. DO NOT mount the
E/H brake actuator near the trailer axles or rear of the trailer. Having the wire length
longer than 25 feet may cause issues with performance and the normal operation of
the unit.
It is critical that the BLACK power lead and WHITE ground lead from the tow vehicle
to the input of the actuator are sized and properly terminated (i.e. dedicated 3040* amp circuit on the tow vehicle – 12 gauge wire minimum). 10-gauge wire is
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E/H 1000 & 1600 BRAKE ACTUATORS
OPERATION MAINTENANCE SERVICE MANUAL

Electrical Wire Colors and Function

* Low temperature applications below 0°F require a 40amp circuit.
The blue wire from the electric brake controller is connected through the trailer
plug to the blue wire on the actuator. The yellow wire from the E/H brake actuator
is connected to the cold side of the trailer emergency breakaway switch. Under no
circumstances should the actuator blue wire and the E/H brake actuator yellow
wire be connected together, nor should the blue wire ever be grounded.
The white wire is connected to the trailer ground and also connected to the tow
vehicle ground through the trailer plug. The black wire is connected to the +12V power
line from the tow vehicle. The black wire can also be connected to large on‑board
coach batteries. The black wire is connected to the small breakaway battery only
through the black wire on the charger of the breakaway battery.

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ELECTRICAL INSTALLATION REQUIREMENTS

recommended to optimize performance. Consult the SAE wiring guidelines for proper
trailer electrical harness design.

ELECTRICAL INSTALLATION REQUIREMENTS

Electrical Installation Requirements
Requires an Electric Brake Controller – The Dexter E/H brake actuator is intended to
be used with an electric brake controller in the tow vehicle. The unit will operate with a
wide variety of controllers but provides optimum performance when used with a Dexter
electric brake controller . The electric brake controller must have an output capacity
of at least 5 amps for proper operation of the Dexter E/H brake actuator. Although
compatible, time base brake controllers are not recommended.

CAUTION
It is the responsibility of the end user to ensure that
their electric brake controller is compatible with the
Dexter E/H brake actuator. Dexter Axle attempts to
provide compatibility with most controllers available,
but is unable to anticipate design changes that might
be introduced by the various controller manufacturers.

Electrical Connections – Make sure all electrical connections are clean, dry,
weather tight, and secure to prevent damage to the wiring from dragging or becoming
entangled with foreign objects. A dedicated ground connection between the tow
vehicle and trailer is also required.
Breakaway Battery Requirement – To comply with federal requirements, the trailer
must be equipped with a breakaway switch and battery. The breakaway battery needs
to have a minimum capacity of 9 amp hours and needs to be maintained in a fully
charged condition at all times. The breakaway battery should be checked for proper
charge level before every use.
Charging the Breakaway Battery – The breakaway battery must be kept fully charged
at all times in order to function properly. Use only those breakaway battery kits that
include a charging device. Do not attempt to charge the breakaway battery directly
from the tow vehicle without the appropriate charging device.

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Test Electrical Operation
2. Pull the breakaway switch. The Dexter E/H brake actuator should run. If the
unit does not run, check breakaway battery condition and system wiring. Reset
the breakaway switch, which will turn the unit off.
Note: When the unit is running, the motor will generate a “hum” that changes
pitch as the unit builds pressure. This is normal.
3. Connect trailer plug to tow vehicle.
4. Turn the ignition switch on and turn the electric brake controller on. Whenever
the brake pedal is depressed, the Dexter E/H brake actuator should run with
time based controllers. Inertia type controllers will often require the vehicle to
be moving in order for the Dexter E/H brake actuator to come on by means of
the brake pedal. If the unit does not run, check system wiring.
5. Apply the controller manual slide. The Dexter E/H brake actuator should run
and brake lights come on.

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CAUTION

Testing the Dexter E/H brake actuator confirms that it
is operating. It DOES NOT confirm that the brakes are
operating properly. Regular inspection, adjustment,
and maintenance of the brakes, lines, hoses, drums,
discs, fluid, and other associated components is
necessary to ensure proper brake operation.
6. Some brake controllers will not produce a high enough signal voltage to
actuate the trailer brakes when the vehicle is at a standstill. Minimal trailer
brake force is produced when the controller voltage output to the E/H brake
actuator is at least 3 VDC. Maximum trailer brake force is achieved at 12 VDC
on the actuator blue wire.
7. When the tow vehicle brakes are released, the unit may continue to run for a
few seconds.

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ELECTRICAL INSTALLATION REQUIREMENTS

1. Attach the trailer to the towing vehicle. Do not connect trailer plug to tow
vehicle until step #2 is completed.

BLEEDING AND BRAKE ADJUSTMENT

Bleeding and Brake Adjustment
1. It typically is much easier to bleed the brakes with two people working
together.
2. Special care must be taken to insure that the Dexter
E/H brake actuator does not run out of brake fluid. Check the fluid level
frequently during the bleeding process.
3. Block the wheels on the trailer and towing vehicle.
4. If the trailer is equipped with drum brakes, check that the brake running
clearances are properly adjusted consistent with the trailer manufacturer’s
recommendations.

CAUTION
Failure to properly adjust the brakes on trailers
equipped with drum brakes can result in slower
response time of the Dexter E/H brake actuator.
5. Install plastic tubing onto the bleeder screw of the wheel cylinder/caliper
farthest from the Dexter E/H brake actuator. If towed vehicle has multiple
axles, always start with the rear axle first.
6. Immerse the free end of the plastic tube in a clean clear container partially
filled with brake fluid.
7. Open the bleeder screw one half turn on the wheel cylinder/caliper.
8. To activate the Dexter E/H brake actuator, turn the ignition switch on and use
manual slide on the brake controller.
9. Watch the free end of the bleeder hose for air bubbles escaping into the clear
container. Continue to bleed the wheel cylinder/caliper until the fluid becomes
clear and free of bubbles.

CAUTION
Do not run the Dexter E/H brake actuator without
adequate brake fluid in the reservoir as it may damage
the unit and void the warranty. Check all bleeder screws
to ensure that they are securely closed and do not leak.

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Bleeding and Brake Adjustment

11. Refill the Dexter E/H brake actuator with brake fluid.
12. Continue the above process (steps 5 through 11) on the next farthest brake
away from the actuator.
13. Repeat these steps until all the brakes have been bled.
14. New trailers with disc brakes should be bled at least twice. Any air in the brake
system will cause brake delay with an E/H brake actuation system.

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OPERATION MAINTENANCE SERVICE MANUAL

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BLEEDING AND BRAKE ADJUSTMENT

10. Tighten the bleeder screw, turn off the Dexter E/H brake actuator, and remove
plastic tubing from the bleeder screw. Bleeding of the wheel cylinder/caliper is
now complete.

ELECTRIC CONTROLLER UNIT TESTING/ADJUSTING

Electric Controller Unit Testing/Adjusting
1. Adjust the gain setting on the electric brake controller to a mid range setting.
2. Drive vehicle at 10 to 15 m.p.h.
3. Apply the brakes. If braking is too severe, adjust the gain setting down to
decrease pressure and retest. If braking is inadequate, increase the gain
setting on the electric brake controller and retest.
4. Repeat this process until the brakes respond appropriately.

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CAUTION