Operating Trailers with Disc Brakes
Many ShoreLand’r trailers come with disc brakes as standard equipment. This system is designed to
brake in both forward and reverse, therefore the brakes must be disengaged to back up.
IMPORTANT: To properly operate this system the tow vehicle MUST be equipped with a matching
5-prong trunk harness to power the solenoid.
How the Solenoid Lockout Works
The disc brake actuator has a lockout solenoid that is activated by the tow
vehicle’s back-up lights. When the vehicle is put in reverse the solenoid
redirects the brake fluid back into the actuator reservoir rather than applying
pressure to the brakes. Then, when the tow vehicle is put into park, neutral or a
forward gear the solenoid returns to its original position allowing the brakes to
function normally during travel.
Alternatives to the 5-Prong Harness
As stated above, the best way to operate the solenoid is with a 5-prong wire
harness on the tow vehicle that matches the wire harness plug of the trailer.
This allows the solenoid to be plugged in at the same time the trailer lights are
connected for towing. If a 5-prong harness is not available there are a number of
short-term fixes that will allow you to use the trailer.
UFP Actuator Lockout Key
UFP actuators are shipped with a lockout key attached to the side of the
actuator on a short cable. The round end of the key is simply inserted in
the slot on the side of the actuator. When the key is in the slot the trailer
can be backed without the brakes engaging. When the trailer is moved
forward the key will fall out of the slot. The key fits very loosely to insure
that it will not remain in the slot after backing. Leaving the lockout key in
the slot would disable the brake system during normal use, which could
result in a serious accident.
Adding a 5th Wire and Plug
A separate wire and plug can be wired into the tow vehicle back-up lights
that can be plugged into the fifth wire of the trailer harness.
The solenoid will work as described above, however this new wire will have
to be plugged into the trailer harness separately.
Using a 4-prong Plug
If the tow vehicle is equipped with a 4-prong plug, the trailer can still be
moved using the solenoid to lock out the brakes. Though not ideal, this is
acceptable for backing trailers in either a storage yard or a shop
environment where the tow vehicle is not the normal vehicle that will be
used with the trailer.
Trailer’s 5-prong wire harness
Required 5-prong trunk harness on tow vehicle
UFP actuator with lockout key
Before backing, simply unplug the trailer’s 5-prong harness from the tow
vehicles 4-prong trunk harness. Turn the harness 90 degrees and plug the
blue wire on the 5-prong harness into the brown wire on the 4-prong harness.
To activate the solenoid, turn on the tow vehicle’s lights. The power for operating the running lights will operate the solenoid disengaging the brakes so the
trailer can be backed up.
Turn plug to connect the blue wire to the brown wire
Midwest Industries, Inc. Ida Grove, IA 51445 800.859.3028 www.shorelandr.com 0003175
REV A 12/14/04
Lockout Brackets for Dealer Yard Trailers
WARNING: These brackets disable normal brake operation and
are NOT intended for consumer use.
These specially designed brackets lay on top of the actuator and prevent the
inside portion from moving when the trailer is backed up. It is NOT intended
for consumer use because, unlike a lockout key, it will not fall out when the
trailer is pulled forward. They are specifically designed for use by authorized
dealers in a yard environment and MUST be removed before regular operation of
the trailer. Failure to do so may result in a serious accident.
These brackets are available through Midwest Industries Customer Service
Department at a cost of $5.00 each. Please specify part # 36352 for Demco
actuators or part # 34551 for UFP actuators. For more information please call
(800) 859-3028.
34551 Lockout bracket for UFP actuators
36352 Lockout bracket for Demco actuators
Midwest Industries, Inc. Ida Grove, IA 51445 800.859.3028 www.shorelandr.com 0003175
REV A 12/14/04