The browser you are using is not supported. Please consider using a modern browser.
Trailer Maintenace
Tie Down Model 85, 85-3/4 & 85E Actuators – Installation Instructions & Owner’s Manual (PDF)
The parts list for the Model 85, 85-3/4 & 85E Actuator can be found in the Installation Instructions.
The Tie Down Model 85, 85-3/4 & 85E Actuator Installation & Owner’s Manual delivers comprehensive instructions for installing, operating, and maintaining these high-capacity hydraulic actuators. Built for demanding trailer setups, these models provide consistent braking strength and durability.
Key topics covered in the manual include:
-
Safety Guidelines: Proper brake fluid use, installation safety, and towing precautions.
-
Installation Instructions: Detailed steps for actuator mounting, hydraulic line routing, and setup for disc or drum brake systems.
-
Operation Details: How the actuators engage under braking loads, coupler use, and towing checks.
-
Maintenance Procedures: Regular fluid inspections, lubrication, hardware checks, and preventive care for dependable operation.
-
Troubleshooting Support: Common actuator issues such as latch misalignment, brake drag, leaks, or poor braking response, with corrective actions.
This manual is an essential reference for technicians, installers, and trailer owners working with the Tie Down Model 85, 85-3/4, and 85E hydraulic brake actuators.
85, 85.75, 85E Actuator Instructions
Maintenance Instructions for Model 85, 85-3/4 & 85E Actuator
- Always check the brake fluid reservoir before using trailer. Make sure it is at least half full. If not, re-fill to approx. 3/8 inch below the top of the reservoir with DOT 3 brake fluid. Check for leaks and repair as required. Never reuse brake fluid.
- The model 80 is equipped with two “Super Lube” pins to provide grease to the inner rollers. Use a grease gun to lubricate the rollers through the grease fittings provided, every 6 months. For heavy use, grease every 3 months.
- To extend coupler and ball life, coat both with a thin coating of grease. This will also eliminate squeaking. Wipe clean and renew grease film each time trailer is used.
- Examine the actuator for bent parts or wear each time the trailer is used. Replace parts as necessary.
- There are no user adjustments on the actuator.
- Actuator travel (shown by coupler roller path) over one inch indicates a need to adjust the brakes or add fluid to the reservoir or a need to bleed the brakes and check connections for leaks. Adjust per instructions found in brake installation manual. In general, back-off the adjusters on drum brakes from locked position, as required. Adjust Free-Backing brakes by rotating wheel in forward direction only. Failure to adjust may result in loss of braking. Disc brakes do not require adjustment, check for pad wear periodically.
- While towing, if the actuator appears to be knocking against the hitch ball while starting or stopping, check brake fluid reservoir and fill if below 3/8” full from the top. Dampening shock absorber requires sufficient brake fluid in order to retard movement of coupler against hitch ball during towing.
What is the rated capacity of my Model 85, 85-3/4 & 85E actuator?
RATED CAPACITY: Maximum Actuator Capacity: 8500 lbs. Gross Load, 850 lbs. Maximum Tongue Load. Minimum tongue weight is 5 percent of the Gross Vehicle Weight (GVW) of the trailer.
The actual in-service rating is limited to that of the ball and hitch being used or the trailer manufacturer’s G.V.W.R. shown on the certification label, whichever is lower (Note: GVWR is the Gross Vehicle Weight Rating which includes the trailer and the load weight as a Total Gross Weight).
How do I bleed my Model 85, 85-3/4 & 85E actuator master cylinder and brakes?
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.
How do I hitch my trailer with the Model 85, 85-3/4 & 85E actuator? Venture Trailers PRIVACY TERMS OF USE CONTACT
- The vehicle, towing hitch and ball must have a rating equal to or greater than trailer GVWR.
- Model 85 will accept 2-5/16” trailer hitch balls with a 8500# capacity only. Trailer balls larger than 2-5/16” or out of round will not fit the coupler or may result in coupler failure. Balls smaller than 2-5/16” can cause shock loading and sudden disconnection. Make certain ball latch is in correct position to retain the hitch ball. Push latch lever back until safety latch engages plate below lever latch. Always insert safety pin into forward hole as a safety lock for the hitch ball coupler prior to towing. Do not tow trailer if coupler is damaged.
- Connect safety cables or chains using crossed pattern under tongue, or follow trailer manufacturer’s directions.
- Connect actuator breakaway cable S-hook to the tow vehicle only. Do not connect S-hook to the safety cables or chains.
- The breakaway system is designed to only operate after the trailer detaches from the tow vehicle and the safety cable/chains have failed. The breakaway is not a parking brake. Do not use as such.
- If the breakaway is accidentally applied while un-hitching, insert a flat bladed screwdriver into the spring clip slotted hole under the actuator and pry down to release.
- Any control devices that restrict operation of the actuator cannot be used. This includes certain sway control devices. The actuator must be free to telescope in response to braking requirements.
- Equalizing or weight distributing hitches may be used, allow six to eight inches free chain length. DANGER: Tongue weight outside rating limits will interfere with performance of actuator, and braking system, and the tow vehicle.
- The actuator is designed for use with Free-Backing trailer brakes. To block braking action, (in order to back up) with other types of brakes, use an electric solenoid. For reverse trailer movement when braking is are not required, place the safety pin in the upper hole on the side of the actuator to block movement of the actuator. DANGER: Failure to remove pin will also prevent forward braking. Pin must be in the lower, forward coupler hole as a safety lock for the hitch ball coupler latch when towing at all times.