Troubleshooting HydraStar Actuator Not Releasing Pressure

Published 12/14/2018

Question:

My Carlisle Hydrastar brake system is holding pressure and not releasing the brakes .I have just replaced all calipers and pads and when I apply the electric brakes the actuator kicks in and applies the brakes but they will not release it locks all axles, when I cracked the hydralic line feeding the brakes from the actuator they released instantly so it is not releasing the pressure .Any Ideas would be grateful

asked by: Roydon W

Expert Reply:

I spoke with my contact at HydraStar regarding the issue you're having with the EOH Actuator like # HBA-10 and he has not really heard of this happening before. What he recommends doing is bleeding the trailer brakes to ensure there isn't anything stuck in the system that is causing the pressure build-up.

To do this you will remove the key from the breakaway switch to start the unit and starting with the brake furthest from the actuator open the bleeder screw and keep it open until you see brake fluid free of any air bubbles coming out of the screw. Close the screw and move to the next brake and so on until all the brakes have been bled.

While doing this you will want to monitor the fluid level in the reservoir so that more air is not pumped into the lines because of low fluid level. I have attached a demonstration video that you can also check out.

Hopefully this will resolve the issue but if it does not please let me know and I will be happy to look into this further. It's possible that the actuator itself has gone bad but this would be less likely.

expert reply by: Chris R