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IMPORTANT: READ AND UNDERSTAND THE ENTIRE INSTRUCTION/ASSEMBLY 

PROCEDURE BEFORE INSTALLING YOUR BRAKES AND ACTUATOR.

The Model 750E 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.
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.

Read your tow vehicles owner’s manual on towing capacity and other towing
recommendations before installing brakes or this actuator.  The Model 750E Actuator is 
completely assembled and ready to bolt into place, if not all ready installed. Manufactured 
for tongue sizes: 3”x 3”, 3”x 4” & 3”x 5”.

  1.  Bolt the actuator to the tongue-using grade 5 bolts 1/2 inch in diameter, 4 inches  
    long. Lightweight tongues, less than 11 gauge, require spacer tubes inside the  
    tongue for reinforcement. Attachment strength should equal or exceed than
    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.  Use only DOT-3 heavy-duty brake fluid in the Model 750E 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 7 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.

    Each wheel cylinder must be bleed until all air is out of the lines. Replenish the  
    brake fluid during the bleeding process so the level does not fall below half full level  
    in the master cylinder reservoir. When bleeding and testing is completed, make sure
    master cylinder is filled to 3/8” below the top of the reservoir and filler cap is  
    securely in place.

Page 2

Summary of Contents for 70521

Page 1: ...Model 750E Brake Actuator...

Page 2: ...cking Brake Solenoid 4 Actuator Maintenance 4 Warnings 5 6 Bleeding Instructions 7 8 Part Diagrams and Replacement Parts 9 12 Limited Warranty 13 14 TIE DOWN ENGINEERING 255 Villanova Drive SW Atlanta...

Page 3: ...quire the use of flexible brake lines at the connection POINT on the brake caliper Follow brake manufacturer instructions 3 Use only DOT 3 heavy duty brake fluid in the Model 750E actuator Use a press...

Page 4: ...coupler or may result in coupler failure Balls smaller than 1 95 can cause shock loading and sudden disconnection Make certain ball latch is in correct position to retain the hitch ball Push latch un...

Page 5: ...5 wire connection for this purpose 3 For ease of use tape or band the end of the reverse light wire to the vehicle s trailer electrical connector Maintenance 1 Always check the brake fluid reservoir b...

Page 6: ...and fingers clear as you re set the mechanism hydraulic pressure held in the system may cause the assembly to snap back suddenly WARNING AVOID sharp turns which can cause the actuator to bind or jack...

Page 7: ...ertain that coupler latch safety pin is securely installed into coupler latch WARNING Brake laws sometimes are minimum standards and you may wish to add additional brakes to your trailer Read your tow...

Page 8: ...e stop bracket and NOT in the slot on the e stop bracket See 2A FRONT FRON To bleed master cylinder and brakes install bleeder hose on first wheel cylinder to be bled if tandem axle trailer bleed clo...

Page 9: ...cylinder See 2B The bleeding operation for that brake is complete when bubbling stops Be sure to tighten bleeder screw securely Each wheel cylinder must be bleed until all air is out of the lines Repl...

Page 10: ...00 Parts Diagram Page 9 Model 750E 7 500 lbs Capacity Part 70521 Disc Brake Part 70522 Drum Brake Model 750 7 500 lbs Capacity Part 70501 Disc Brake Part 70502 Drum Brake Model 700 7 000 lbs Capacity...

Page 11: ...ts 1A 70519KD Drum Brake Master Cylinder Kit Enclosed Model Includes master cylinder and cap 4 mounting screws with washers 2 rollers with matching nuts and bolts 1B 11286 Disc Brake Solenoid used wit...

Page 12: ...1A 3 2 1 1 4 5 5 7 1 1 6 5 Classic Model 70 Replacement Parts Page 11...

Page 13: ...h master cylinders 2 47261 Latch Kit Assembly serial numbers 16021 and above 2 47262 Latch Kit Assembly serial numbers 16020 and below 3 50302 Emergency Stop Cable E stop Breakaway serial numbers 1602...

Page 14: ...oduct replace the TIE DOWN product or repair the product TIE DOWN has sole discretion in choosing which option to provide For this LIMITED WARRANTY to apply TIE DOWN must receive notice of the alleged...

Page 15: ...AKES ACTUATORS BEARINGS HOSE AND TUBING PURCHASER S RECOURSE SHALL BE LIMITED TO ANY WARRANTY OF THE RESPECTIVE MANUFACTURERS THIS WARRANTY EXCLUDES ALL IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNES...

Page 16: ...ENGINEERING www tiedown com 255 Villanova Drive SW Atlanta GA 30336 404 344 0000 Fax 404 349 0401 2014 TIE DOWN Inc ALL RIGHTS RESERVED Instruction 08164 2 Model 750E Brake Actuator Owners Manual 0512...

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