Attach brake line to solenoid. Do not use thread sealant on
this connection.

2. Attach one of the two leading wires to the center pin of the
trailer connector (usually yellow or purple wire).
3. Ground the remaining solenoid wire to the trailer frame.
4. Ensure the center pin of the 7-way connector is attached to
reverse lamp circuit.

CAUTION
CONNECTING TO THE WRONG PLUG WILL CAUSE THE BRAKES TO FAIL

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LIGHT DUTY SURGE ACTUATOR
INSTALLATION MANUAL

4.1 - STANDARD PROFILE

4.2 - LOW PROFILE

1.

Two people are required for this operation.

Ensure that the bleeding access port matches Figure 4A
before pumping. If it looks like 4B, gently push on the coupler
until you can see the rounded corner of the e-stop bracket.

1.

Bleeding Access Port

Remove the master cylinder reservoir plug and fill the
reservoir with brake fluid. Fluid will need to settle until
completely free of air bubbles.

2. Bleed the actuator master cylinder by inserting a screwdriver
through the hole of the inner member button. Use short
strokes to pry on the pushrod (while holding the safety release
bracket up) until no air bubbles are seen coming from a small
orifice hole in the bottom of the master cylinder reservoir.
Figure 4A:
Correct access hole

Figure 4B:
INCORRECT access hole

Acuator
Tongue

Insert
screwdriver
tip here

2. If you can’t see the rounded corner of the emergency
breakaway bracket (fig. 4B) through the access port, gently
push the coupler forward. Do not place a screwdriver in the
access port until the rounded edge of the e-stop bracket can
be seen through the port(fig. 4A).
3. Place the tip of a flat screwdriver in front of the e-stop
bracket (fig. 5A).
Figure 5A:
Correct screwdriver tip position

Figure 5B:
Master cylinder pumping

3. The first person slowly strokes the pushrod while holding the
safety release bracket.
4. The second person opens the bleed screw fitting, then closes
the bleed screw fitting BEFORE the first person SLOWLY
releases the pushrod. Repeat this procedure until the fluid
expelled from the bleeder hose is free of air bubbles.
5. Remember to always tighten the bleeder screw before releasing
the pushrod. During this procedure, the master cylinder
reservoir fluid level must be maintained at no less than half full.
6. Repeat steps 4 and 5 for the brake on the other side of the
axle. Then repeat on any additional axle sets for tandem or
triple configurations.
7.

Repeat rear axle bleeding on multiple axle configurations to
ensure air is out of the system.

8. Stroke the pushrod and check to be sure the brake system is
pressurized by attempting to rotate a tire.
9. Push up on the safety release bracket to ensure that the
pushrod is in a released position.
10. After bleeding has been completed, recheck the fluid level in
the master cylinder. Fill the master cylinder reservoir to the
indicator on the reservoir plug. Do not overfill.

4. While keeping pressure, pump the master cylinder using
the screwdriver (fig. 5B). Crack the bleeder valve open and
tighten. Repeat until there are no more air bubbles.
5. The screwdriver should be at the lowest angle possible to the
actuator so that it slides in front of the e-stop bracket (Fig. 5A).
6. Push the screwdriver forward and back to pump the master
cylinder (fig. 5B).
7.

The bleeding operation for that brake is complete when
bubbling stops. Be sure to tighten the bleeder screw securely.
Each wheel cylinder must be bled until all air is out of the lines.

8. Replenish the brake fluid during the bleeding process so the
level does not fall below half full level in the master cylinder
reservoir.
9. Continue on to section 5.

LIGHT DUTY SURGE ACTUATOR
INSTALLATION MANUAL

2024.02 | 7

SECTION 5 - TRAILER HITCHING

CAUTION
ENSURE YOU HAVE THE CORRECT BALL SIZE FOR YOUR COUPLER.
A LOOSE FIT BETWEEN THE COUPLER AND HITCH BALL CAN CAUSE
THE ACTUATOR AND HITCH BALL TO SEPARATE, CAUSING SERIOUS
DAMAGE, INJURY OR DEATH. CHECK COUPLER EVERY TIME PRIOR
TO TOWING. COUPLER LATCH SAFETY PIN MUST BE SECURELY
INSTALLED INTO COUPLER LATCH BEFORE TOWING.

5.1 - DROP-N-GO™ COUPLER
1.

This coupler is self-latching and does not require the latch
handle to be in the unlatched position to insert the hitch ball.

rest on top of the plate, the plate then rests on top of the
coupler nose when the latch is properly closed.
5. Lightly lift up to see if coupler will lift to ensure it is
completely latched.
6. Insert hitch pin into hole on side of coupler latch handle. If
the hitch pin cannot be reinserted, the ball is not properly
aligned or is damaged.
7.

Connect safety cables or chains using crossed pattern under
tongue, or follow trailer manufacturer’s directions.

8. Connect actuator breakaway cable S-hook to the tow vehicle
only. Do not connect S-hook to the safety cables or chains.
9. Continue to section 6.

2. To latch coupler onto the hitch ball, position the tow vehicle
so the hitch ball is directly under the coupler socket.
3. Make sure the hitch pin is removed from side of coupler.
4. Lower the coupler over ball. The coupler handle will remain
in a horizontal position, but will rise and then self-latch and
lower itself when the coupler is fully seated onto hitch ball.
5. If the hitch pin cannot be reinserted, the ball is not properly
aligned or is damaged. DO NOT FORCE THE COUPLER TO
LATCH. Replace ball if necessary. Once the handle is fully
closed, insert hitch pin fully into hole on side of coupler.
6. Lightly lift up to see if coupler will lift to ensure it is
completely latched.
7.

Connect safety cables or chains using crossed pattern under
tongue, or follow trailer manufacturer’s directions.

8. Connect actuator breakaway cable S-hook to the tow vehicle
only. Do not connect S-hook to the safety cables or chains.
9. The breakaway system is not a parking brake. It is designed to
operate if the trailer and the safety cable/chains have failed.
10. Continue to section 6.

5.2 - MANUAL AND LEVER LOCK COUPLER
1.

Hitch trailer by placing coupler socket over the ball. Ensure
that the ball is not underneath or pressing directly on the
pawl/jaw of the coupler.

2. Lower coupler and close handle. Coupler handle should close
with minimal force. If handle does not close, the hitch ball
is not fully inserted into coupler socket, the hitch ball is
oversized or egg-shaped. DO NOT FORCE HANDLE. Replace
ball if necessary.
3. Verify that ball is completely inserted into coupler socket by
looking into the hole on top of coupler body and the tow ball
top can be seen just below the hole.
4. Verify that the latch handle, the plate below it, and the top
of the coupler are all in contact. The closed latch should
8 | 2024.02

LIGHT DUTY SURGE ACTUATOR
INSTALLATION MANUAL

SECTION 6 - BEFORE TOWING

6.2 - ROAD TESTING

6.1 - EMERGENCY BREAKAWAY CABLES

1.

CAUTION
THE BREAKAWAY SYSTEM IS NOT A PARKING BRAKE. IT IS
DESIGNED TO OPERATE IF THE TRAILER AND THE SAFETY CABLE/
CHAINS HAVE FAILED.

BEFORE TOWING, IT IS CRITICAL TO ENSURE THE EMERGENCY
BREAKAWAY SYSTEM IS NOT ENGAGED.

STANDARD ACTUATORS:
The emergency breakaway stop button is located on the side of
the actuator. Ensure it is in the normal operating position before
towing.
FRONT
If button stop cable is showing
Normal operating position
DO NOT TOW TRAILER

Ensure that trailer lights are operational.

2. Disconnect the trailer plug from tow vehicle. This will also
disconnect the solenoid. Attempt to back up the trailer on
a slight incline, which should be difficult or not possible if
brake bleeding has been completed correctly. If you can
reverse the trailer easily, there is still air in the brake
system and the bleeding process will need repeated.
3. Additional step for low profile - pull trailer forward and stop
suddenly, the actuator front slider pin should not travel
more than halfway in slot for single axle or 3/4-way in slot
for tandem axles.
4. After the initial trailer braking test, recheck fluid in the
actuator and refill as necessary. If the master cylinder fluid
is extremely low or dry after the bleeding process, the
bleeding process will need to be repeated.
5. Check for leaks at all fittings and connections and tighten or
correct as necessary. Properly dispose of fluid.

6.3 - TOWING CONSIDERATIONS
Avoid sharp turns and towing over large bumps as this can
damage the actuator, trailer, or tow vehicle.

LOW PROFILE ACTUATORS:
1.

Locate the pushrod release tab on the underside of the
actuator, just behind the coupler socket.

2. The pushrod release tab should push up with slight pressure
and nothing else should happen. If you hear a noise, similar
to a loaded spring releasing, this can be a sign that the
trailer brakes were inadvertently set and the cause should
be investigated.

The actuator will not operate when backing down a hill, use
caution as your tow vehicle brakes will be your only stopping
power.
Brake and actuators can overheat and fade after periods of long
braking. Take the time to learn the proper procedure for trailer
braking before use.

3. If the pushrod release tab is jammed or is damaged, the
emergency breakaway system needs serviced.

Pushrod Release Tab

Pushrod Access Hole

LIGHT DUTY SURGE ACTUATOR
INSTALLATION MANUAL

2024.02 | 9

NOTES

10 | 2024.02

LIGHT DUTY SURGE ACTUATOR
INSTALLATION MANUAL

NOTES

LIGHT DUTY SURGE ACTUATOR
INSTALLATION MANUAL

2024.02 | 11

OVER 450+
NORTH AMERICAN

DISTRIBUTION

LOCATIONS

FOR ALL YOUR TRAILER PARTS NEEDS
FIND THE LOCATION CLOSEST TO YOU BY
SCANNING THE CODE OR VISITING
WWW.DEXTERAXLE.COM/DISTRIBUTORS

NO PART OF THIS MANUAL MAY BE REPRODUCED WITHOUT DEXTER’S PERMISSION.
ALL PART NUMBERS, DIMENSIONS AND SPECIFICATIONS IN THIS MANUAL ARE SUBJECT TO CHANGE WITHOUT NOTICE.

LIGHT DUTY SURGE ACTUATOR
INSTALLATION MANUAL

LIT-750-00
2024.02
© 2024 DEXTER AXLE COMPANY