Bleeding Procedure for Titan Aero 7500 Disc Trailer Brake Actuator

Updated 01/06/2014 | Published 12/29/2013

Question:

I had a boat mechanic install the T4843500 kit on my boat trailer. He bled the brakes by removing a bolt from the activator and compressing the tongue with a 2x4. Hes a nice guy but . . . and he asked me why one of the bolts in the lower parts of the activator was loose. Do you have a manual and a blowup of this activator so I can check that it is working properly on my trailer and also I need info on bleeding. He didnt keep any of the paper that came in the kit package. Hes not dumb, just not sure and is concerned that the job was done right.

asked by: Bob J

Helpful Expert Reply:

The actuator in disc brake kit, T4843500, is the Aero 7500 T4606500. I have included an exploded view of the actuator. Below are the bleeding instructions.

Fill the system with DOT 3-4 heavy-duty brake fluid. The braking system may be bled manually or with a vacuum or pressure type brake bleeding system. Both types of brake bleeding equipment should be available at your local automotive jobber. Follow manufacturers instructions.

After completing the Installation instructions, remove the master cylinder cap and fill the reservoir to three quarters full with DOT-3 brake fluid. DO NOT allow brake fluid to contact painted surfaces since it will damage the finish. Wipe up any spills immediately and wash the area with water.

If you choose to manually bleed the system, an assistant makes the job easier. Disconnect the trailer from the tow vehicle and hook the safety chains (NOT the actuator breakaway cable) together to form a loop. The loop should be centered below the actuators coupler.

Place a sturdy board such as a 2 x 4 into the safety chain loop below the coupler. The board should be four feet long or more so it will extend well above the actuator. Position the board to press against the front end of the actuators coupler and use it to force the coupler case into the actuator’s outer housing. This pumps the brake fluid into the trailer braking system. Manually pull the coupler case back to fully extended position and repeat the process.

When the air bubbling stops inside the master cylinder, install a bleeder hose on the bleeder screw of the first wheel cylinder or disc brake caliper to be bled. Be sure to use the bleeder screw on top of the caliper. Start with the rear axle on tandem axle trailers. Submerge the other end of the hose in a glass container of brake fluid so that air bubbles can be observed. Open the bleeder screw one turn before pushing the coupler case in. When the coupler is pushed completely in, the bleeder screw should be closed to prevent air from being pulled back into the system. Air trapped in the brake lines will greatly reduce your braking efficiency. Repeat this process until no more bubbles are released with each stroke. Be sure to close the bleeder screw securely.

Repeat the bleeding operation at each wheel cylinder or caliper. During the bleeding process, replenish the brake fluid so the level does not fall below half full level in the master cylinder reservoir. When bleeding is complete, fill the reservoir to within 3/8 inch of the top. Install the filler cap securely.

expert reply by: Michael H