* NOTE: <#> is the reference number shown in the assembly diagram of the actuator located at the end of this manual
Page 3 of 13
INSTALLATION (cont.)
Brake Fluid Filling and Bleeding
6.
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 manufacturer's instructions.
6a.
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.
6b.
If you choose to manually bleed the system, an assistant makes the job easier. Please note the diagram in
figure 2 (on the next page). 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 actuator’s
coupler as shown in Figure 2.
6c.
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 actuator’s 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.
6d.
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.
6e.
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” of the top. Install the filler cap securely.