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 2023 OWNER’S MANUAL 
ELECTRIC-OVER-HYDRAULIC 
BRAKES (OPTIONAL): 
Electric-over-Hydraulic (EOH) brakes utilize an electrical 
signal from a vehicles OEM or aftermarket brake controller to 
activate a hydraulic brake pump that will apply the trailer brakes. 
MasterCraft utilizes the HydraStar™ Hydraulic Brake Actuator in 
this application. The HydraStar™ Actuator is installed inside the 
tongue assembly of your MasterCraft Trailer. 
EOH brakes oer a smoother and stronger brake application 
when compared to surge brakes, however, the tow vehicle being 
used MUST be fitted with an electronic brake controller and the 
appropriate 7-pin trailer connector. 
Because the HydraStar™ Actuator is a hydraulic pump, it may 
overheat in certain situations when the brakes applied for 
extended periods of time, such as railroad crossings or trac 
jams. It is important to apply the parking brake on the tow  
vehicle and release the brake pedal so that the pump does not  
run continuously. 
The emergency breakaway system on the MasterCraft EOH 
system utilizes a battery installed in the trailer tongue to activate 
the pump in the case that the trailer becomes separated from 
the tow vehicle. It is critical to ensure the battery is maintained 
and properly charged before towing the trailer. In typical use, the 
battery is charged when connected to the tow vehicle.  
After periods of storage, the battery may have lost charge and 
must be recharged or replaced before towing. 
The breakaway system is NOT to be used as a parking brake.  
The HydraStar™ unit may overheat and/or discharge the battery 
resulting in loss of braking pressure. 
Proper operation should be tested before use. For a simple test, 
perform the following steps: 
•  Attach the trailer to the tow vehicle 
•  Pull the breakaway switch on the trailer. 
 • Listen for a hum from the tongue, the sound will change as the 
unit builds pressure. 
 • This shows that the battery has charge and the pump is working. 
•  Reset the breakaway switch to turn the actuator pump off. 
•  Turn the vehicle ignition and brake controller on. 
 • Depress the brake in the tow vehicle. 
 • The hydraulic pump should activate when the brake pedal  
is pressed. 
 • This shows that the wiring is correct. 
•  The above steps show that the pump is working but the disc 
brakes still need to be tested.