Troubleshooting Trailer Brakes Malfunction with Electric Over Hydraulic Drum Brake System

Updated 02/14/2019 | Published 02/12/2019

Products Featured in This Question

Hydrastar Electric Over Hydraulic Actuator for Drum Brakes - 1,000 psi

(73)

$1041.78

Tekonsha Prodigy P3 Trailer Brake Controller - 1 to 4 Axles - Proportional

(6643)

$155.79

Hook Probe Circuit Tester

(60)

$12.27

Hand Vacuum Pump Brake Bleeder

(10)

$39.41

Question:

I have no idea what to do I work for a transportation company and I drive a 2014 Dodge Ram 5500 with a 3 car trailer with your breaking system on it The problem I am having over and over is there is air getting in to the system some how It works just fine and then there is no trailer breaks And it wares the pads uneavenly We have made contact with your company and you have sent out a new master Cylinder And we still have the problem all of the break lines on the trailer are new Lines I am worried about my job..or wrecking or killing some one Any advice would help thank you

asked by: Josh

Expert Reply:

Air in your hydraulic lines when using the HydraStar Electric Over Hydraulic Actuator for Drum Brakes - 1,000 psi # HBA-10 with new lines would only be a leaking master cylinder, leaking brake cylinder or in the drum brake assembly or improper brake bleeding.

Most of the time, the brake bleeding is the issue because you need start with the brake assembly with the longest line from the master cylinder and then move to the next longest until you are all the way through your system I recommend using the Hand Vacuum Pump Brake Bleeder # PTW87030 and getting some extra bottles of Dot 3 or Dot 4 brake fluid (whichever you are using) for your application because if the master runs out of fluid part way through you will add air to the lines and need to start over. I recommend putting cardboard under any fittings and pumping the brakes then let sit for a while and check for leaks.

The only other part that could cause lack of braking would be the electrical wiring and losing power or ground. I recommend removing your ground connection, cleaning the area with sand paper and then reconnecting it bare metal to metal. Then check to make sure you are 12 volt constant power as well as brake controller output power consistently using a circuit tester like # PTW2993. If there is a short in either wire, you may get random power or lack of power and those lines would need replaced. Finally make sure your brake controller is compatible with your actuator as certain models like the Prodigy P3 # 90195 are far better with EOH systems than controllers and even has a specific mode for this.

If you are unsure about any of this, you need to take it to a mechanic so that you and others on the road are safe.