How to Test Hydrastar Brake Actuator to See if it is Bad

Updated 09/02/2025 | Published 06/28/2025

Question:

I have a Hydrastar MHBA-16-1600 psi with a Cargo HBA-CAM 381-7073 on a triple axle boat trailer. This is connected to my Silverado 2012 3500 HD and has worked for years. The brakes have stopped working. I have used a meter and made sure I am getting the set voltage to the blue wire going to the brake controller, now set for 6.5 volts. I can hear and feel the Hydrastar click when the brakes are applied but the electric motor does not operate. What is the best way to determine if this is the Hydrastar with issues or the HBA-CAM which is causing the issues? If the Hydrastar is bad can I rebuild it?

asked by: Shane H

Expert Reply:

Hello Shane,

My apologies for the delay in getting an answer, we had quite the spike in questions and are getting caught up. I also had to wait for a response from Hydrastar, this is what they sent to troubleshoot:

1. Check to ensure unit is receiving power from the tow vehicle (black= 12-volt constant power, blue = 10-12 volts during brake activation, white = ground)

2. Check Breakaway Battery System wiring. Blue brake controller wiring from the Hydrastar™ should NOT be wired in to the Breakaway Battery System.

3. If the problem is not solved, conduct Battery Test (see Battery Test Procedures) (I attached the image)

4. If actuator passes Battery Test the problem is not in the actuator. If the actuator fails the Battery Test, please let me know so I can get you in contact with the technical department directly.

Were you able to get it figured out already? If so, what did you find out?

expert reply by: Kate F

How to Test Battery
(click to enlarge)

Kate F.

9/2/2025

Hey Shane, Were you able to figure out if the issue was with the Hydrastar or the HBA-CAM? If so, what did you find out? If you’re still looking for a solution, I’m happy to help.