Tie Down 85E Actuator - Manual

TIE DOWN ENGINEERING • 255 Villanova Drive SW • Atlanta, GA 30336
www.tiedown.com (404) 344-0000 Fax (404) 349-0401
Installation Instructions and Service Manual
Model 85, 85-3/4 & 85E
Actuator* for
Trailer Brakes
8,500 lbs. Capacity for use with
2-5/16” Hitch Balls
Drum Brake Ready - Part #47236
Disc Brake Ready - Part #47275,
#47237, #47274 & #47235
*US Patent No. 6,375,211
MODEL 85 ACTUATOR INSTALLATION INSTRUCTIONS
IMPORTANT: READ AND UNDERSTAND THE ENTIRE INSTRUCTION/ASSEMBLY PROCEDURE BEFORE INSTALLING YOUR BRAKES
AND ACTUATOR.
The Model 85 works by the “surge” or “push” of the trailer toward the tow vehicle. This automatically synchronizes the trailer brakes with
the tow vehicle axle brakes. When the trailer pushes against the tow vehicle, the actuator telescopes together and applies the force to the
master cylinder, supplying hydraulic pressure to the brakes. The built in dampening shock absorber retards the telescoping shock against
the hitch ball by depending on the brake fluid in the master cylinder. Low levels of brake fluid will signal the tow vehicle operator to add
brake fluid via coupler knocking.
Be sure to comply with regulations for brakes in your state. Brake laws sometimes are minimum standards and you may wish to add
additional brakes to your trailer to meet minimum Gross Vehicle Weight Ratings (GVWR). Read your tow vehicle owner’s manual on towing
capacity and other towing recommendations before installing brakes or this actuator.
The Model 85 Actuator is completely assembled and ready to bolt into place (Tongue sizes: 3”x3”, 3’x4” & 3”x5”).
1. Bolt the actuator to the tongue-using grade 5 bolts 1/2 inch in diameter, 4 inches long. Lightweight tongues, less than 10 gauge, require
spacer tubes inside the tongue for reinforcement. Attachment strength should equal or exceed 1-1/2 times trailer G.V.W.R.
2. Hydraulic brake lines should be installed on the trailer as described in the installation manual supplied with the brakes. Note: Some disc
brakes require the use of flexible brake lines at the connection POINT on the brake caliper. Follow brake manufacturer instructions.
3. Tie Down’s actuators feature a shock dampener that uses brake fluid from the master cylinder. The dampener must be primed before
bleeding or using trailer. To prime the dampener, fill the master cylinder with DOT 3 brake Fluid. Push the coupler into the housing and
slowly pull out 3 times, then refill master cylinder.
4. Use only DOT-3 brake fluid in the Model 85 actuator. Use a pressure type brake bleeder to bleed brakes. (This type of brake bleeder is
available at your local automotive jobber.) Follow manufacturer’s directions. Or, manually bleed the brakes using a heavy-duty flat blade
screwdriver inserted in the hole provided on top of the actuator near the front. Insert the screwdriver and use a pumping action to
activate the master cylinder in order to bleed the brakes. See page 8 for more details.
To bleed master cylinder and brakes, install bleeder hose on first wheel cylinder to be bled; if tandem axle trailer, bleed closest axle
first, and the closest brake on that axle first. Use a loose end of hose from the bleeder valve submerged in a glass container of brake
fluid to observe bubbling (hose must be submerged into clean brake fluid to keep air from traveling back into the brake cylinder).
Loosen the bleeder screw located in the wheel cylinder one turn, the system is now open to the atmosphere. The bleeding operation for
that brake is complete when bubbling stops. Be sure to tighten bleeder screw securely.
030708,C993
Instruction #08110