Test Electrical Operation; Bleeding And Brake Adjustment - Dexter Laundry DX Series Service Manual

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.

Test Electrical Operation

1. Attach the trailer to the towing vehicle. Do not connect trailer
plug to tow vehicle until step #2 is completed.
2. Pull the breakaway switch. The Dexter DX Series 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. Inertia type controllers will often require the vehicle to be
moving in order for the Dexter DX Series 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 DX Series brake
actuator should run and brake lights come on.
CAUTION
!
Testing the Dexter DX Series 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 require a certain speed to actuate
the trailer brakes via the brake pedal. This occurrence will not
produce a high enough signal voltage to actuate the trailer
brakes when the vehicle is at a standstill. Please contact your
vehicle/controller manufacturer for further details.
7. When the tow vehicle brakes are released, the unit may
continue to run for a few seconds.

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 DX Series
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.
DX SERIES SERVICE MANUAL
ELECTRIC/HYDRAULIC ACTUATORS
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 DX Series
brake actuator.
5. Install plastic tubing onto the bleeder screw of the wheel
cylinder/caliper farthest from the Dexter DX Series 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 DX Series 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 DX Series 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.
10. Tighten the bleeder screw, turn off the Dexter DX Series brake
actuator, and remove plastic tubing from the bleeder screw.
Bleeding of the wheel cylinder/caliper is now complete.
11. Refill the Dexter DX Series 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.
CAUTION
Ensure no debris enters the fluid reservoir tank while the cap is
removed. Failure to do so may have an effect on product life.
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