TIE DOWN 750E Troubleshooting guide

Model 750E
Brake Actuator

Installation Instructions and Service Manual
Table of Contents Page
Actuator Installation Instructions 2
Hitching the Trailer 3-4
Vehicle Wiring - Free Backing 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, GA 30336
[phone] • Fax [phone]
© 2014 TIE DOWN Inc., ALL RIGHTS RESERVED
Model 750E - 7,500 lbs. Capacity
Part #70521 Disc Brake
Part #70522 Drum Brake

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

4. Check with your state motor vehicle department for laws concerning minimum
trailer brake requirements. Some states may require brakes on all axles.
5. Road test trailer a short distance to activate the actuator several times. Check fluid
level again. Remember, low brake fluid levels will result in hitch ball knocking.
6. When 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. Road test again to make sure
brakes work properly.
RATED CAPACITY: Maximum Actuator Capacity: 7500 lbs.
Gross Load, 750 lbs. Maximum Tongue Load
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: G.V.W.R. is the Gross Vehicle Weight Rating which includes the trailer and the load
weight as a Total Gross Weight).
Hitching The Trailer
1. The vehicle, towing hitch and ball must have a rating equal to or greater than
trailer G.V.W.R..
2. Model 750E will accept 2” or 50mm trailer hitch balls only. Trailer balls larger than
2.00” (50mm) or out of round will not fit the 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 until safety latch engages plate below latch. 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.
3. Connect safety cables or chains using crossed pattern under tongue, or follow
trailer manufacturer’s directions.
4. Connect actuator breakaway cable S-hook to the tow vehicle only. Do not
connect S-hook to the safety cables or chains.
5. The breakaway system is designed to only operate after the trailer detaches from
the tow vehicle and the safety chains have failed. The breakaway is not a parking
brake. Do not use as such.
6. If the breakaway is accidentally applied, insert a flat bladed screwdriver into the
spring clip on the side of the actuator and pry sideways pressure to release,
see page 8.
7. 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.
8. Equalizing or weight distributing hitches may be used, that are designed to use with
surge brake actuators, allow six to eight inches free chain length.
Page 3

DANGER: Tongue weight beyond rating limits will interfere with performance of
actuator, and braking system, and the tow vehicle.
9. 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 including disc
brakes, use an electric solenoid. For trailer movement when brakes are not required,
place the safety pin in the hole on the side of the actuator housing to block
movement of the actuator.
DANGER: Failure to remove pin will also prevent forward braking. Pin must
be in the lower, forward hole as a safety lock for the hitch ball coupler latch
when towing at all times.
Directions Vehicle Wiring - Brake Solenoid
1. Disconnect trailer hitch and any wiring connectors from the vehicle.
2. Connect a 14 gauge wire to the backup (reverse) light wire of the vehicle. This
wire should be of sufficient length to attach to the existing vehicle/trailer
wire receptacle. The end of this wire will require a female end that will match the
solenoid male connector wire. Your vehicle may have a 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 before using trailer. Make sure it is at least
half full. If not, re-fill to 3/8 inch below the top of the reservoir with DOT 3 brake
fluid. Do not use DOT 5 brake fluid. Check for leaks and repair as required.
Never reuse brake fluid.
2. To extend coupler and ball life, coat both with a thin coating of grease. This will also
eliminate squeaking. Wipe clean and renew film each time trailer is used.
3. Examine the actuator for bent parts or wear each time the trailer is used.
Replace parts as necessary.
4. There are no user adjustments on the actuator.
5. 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 adjusters on drum brakes from locked position, as
required. Adjust Free-Backing brakes by rotating in forward direction only. Failure
to adjust may result in loss of braking. Disc brakes do not require adjustment,
check for pad wear.
Page 4

WARNING
Actuator and brakes should always be flushed with fresh water after using trailer in
corrosive conditions. This includes salt water, fertilizers and other corrosive materials.
Before storing trailer remove brakes and clean thoroughly. It is also wise to repack the
bearings at the same time. Failure to properly and adequately maintain the actuator
could cause serious damage, injury or death.
WARNING
The breakaway system is not designed to operate if the trailer does not separate
completely from the tow vehicle, or if the tongue goes under the rear of the tow vehicle.
WARNING
In the event that the breakaway system is used, check all system components (cable,
S-hooks, etc.) for proper working order. Replace any damaged parts with genuine Tie
Down parts only.
WARNING
When re-setting the break a way system keep hands 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 jackknife against the tow
vehicle or cause a bend in the tongue. Either can damage the actuator causing brake
failure. AVOID towing trailer across large bumps or dips that may over stress the
connection between the trailer and tow vehicle, as this could result in damage to
the actuator.
WARNING
DO NOT REUSE BRAKE FLUID. Always use fresh DOT 3 fluid from a fresh container. Failure
to maintain proper levels of fluid in the reservoir will cause brake failure.
WARNING
Failure to install the hitch pin before towing can result in accidental opening of the coupler
hitch latch which can lead to the trailer coming off of the hitch ball causing serious
damage, injury or death. If pin will not fit into the front lower hole, the coupler is not
attached properly. Re-set coupler on hitch ball.
Page 5
Braking and Trailering Warnings

WARNING
A minimum of 5% tongue weight and a maximum 10% tongue weight of the trailer
G.V.W.R. must be located on the hitch ball. The Trailer tongue should be parallel to the
ground. Too much weight can cause premature brake actuation and loss of control of the
towing vehicle. To little tongue weight can cause the trailer to fishtail, resulting in loss of
control of the tow vehicle and trailer (total trailer weight G.V.W.R. includes weight of the
trailer plus load).
WARNING
A loose fit between the coupler and hitch ball can cause the actuator and hitch ball to
separate, causing serious damage, injury or death. Check coupler every time prior to
towing and at each stop on long trips. Always make certain 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 vehicles owner’s manual on towing capacity and
other towing recommendations before installing brakes or this actuator.
WARNING
Never allow the coupler latch safety pin to remain in the reverse lockout position hole.
After reverse maneuvering, always insert coupler latch safety pin back into coupler
latch. FAILURE TO REMOVE SAFETY PIN FROM REVERSE LOCK OUT POSITION HOLE
WILL PREVENT FORWARD MOVEMENT BREAKING WHICH CAN RESULT IN SERIOUS
PROPERTY DAMAGE, INJURY OR DEATH.
WARNING
Tie Down actuators and brakes are designed to use DOT 3 (or 4) brake fluid.
Do not use of DOT 5 brake fluid. Use of DOT 5 brake fluid will cause damage to internal
parts that can result in loss of brake power.
Page 6

Bleeding Instructions
FRONT
FRONT
FRONT
FRONT
To pump master cylinder, insert a flat tip
screwdriver into the bleeding access port on
top, near the front of the actuator cover
(See right photo and 1A below).
The screwdriver should be at the lowest angle
possible to the actuator so that it slides in
front of the e-stop bracket (See 1B).
Bleeding
Access Port
Screwdriver tip MUST BE IN FRONT of the
e-stop bracket and NOT in the slot on the
e-stop bracket (See 2A).
FRONT FRONT
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.
Page 7

FRONT FRONT
WARNING: If button stop
cable is showing
DO NOT TOW TRAILER
Release emergency stop
cable by prying spring out
with a flat blade screw
driver.
FRONT FRONT
FRONT FRONT
Emergency
Button Stop
Shown in normal
operating position
Emergency Button Stop
Push the screwdriver forward and back to
pump the master 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. 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 8

2
1A
1A
1A
1A
1A
Model 70
“Open”
Master Cylinder
Model 750E
“Enclosed”
Master Cylinder
Model 700 & 750
“Open”
Master Cylinder
1B
1
1
1 & 6
1
4
5
7
5
5
3
3
2
1
1
4
5
5
7
1
1 & 6
5
1B
1C
1B
1C
Model 750E/750/700 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
Part #70464 Disc Brake
Part #70465 Drum Brake

2
1A
1A
1A
1A
1A
Model 70
“Open”
Master Cylinder
Model 750E
“Enclosed”
Master Cylinder
Model 700 & 750
“Open”
Master Cylinder
1B
1
1
1 & 6
1
4
5
7
5
5
3
3
2
1
1
4
5
5
7
1
1 & 6
5
1B
1C
1B
1C
Model 750E/750/700 Replacement Parts List
Page 10
Item # Part # Description
1A 70461K Disc Brake Master Cylinder Kit “Open Model” with gasket,
Includes: master cylinder and cap, 4 mounting screws with washers,
2 rollers with matching nuts and bolts
1A 70461KD Drum Brake Master Cylinder Kit “Open Model” with gasket,
Includes: master cylinder and cap, 4 mounting screws with washers,
2 rollers with matching nuts and bolts
1A 70519K Disc Brake Master Cylinder Kit “Enclosed Model”
Includes: master cylinder and cap, 4 mounting screws with washers,
2 rollers with matching nuts and bolts
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 with Disc Brake Actuators
1C 70470-3 Gasket - For “Open Model” master cylinders
2 70411 Latch Kit Assembly, with Drop N Go Coupler,
(for serial numbers 17926 and below)
2 70412 Latch Kit Assembly, with Drop N Go Coupler,
(for serial numbers 17927 and above)
3 50317 Emergency Stop Cable (E-stop/Breakaway)
4 50301 Safety Cable with stainless steel pin - Includes mounting screw
5 70462K Actuator Covers, Includes: front and rear cover plates and
4 mounting screws
6 48986A Master Cylinder Fill Cap with internal bladder, 2.25” Opening (E-Models)
6 70470-4 Master Cylinder Fill Cap with internal bladder, 1.25” Opening (Open Models)
7 48845 Safety Spring with two mounting screws

2
1A
1A
1A
1A
1A
Model 70
“Open”
Master Cylinder
Model 750E
“Enclosed”
Master Cylinder
Model 700 & 750
“Open”
Master Cylinder
1B
1
1
1 & 6
1
4
5
7
5
5
3
3
2
1
1
4
5
5
7
1
1 & 6
5
1B
1C
1B
1C
Classic Model 70 Replacement Parts
Page 11

2
1A
1A
1A
1A
1A
Model 70
“Open”
Master Cylinder
Model 750E
“Enclosed”
Master Cylinder
Model 700 & 750
“Open”
Master Cylinder
1B
1
1
1 & 6
1
4
5
7
5
5
3
3
2
1
1
4
5
5
7
1
1 & 6
5
1B
1C
1B
1C
Classic Model 70 Replacement Parts List
Page 12
Item # Part # Description
1A 47260K Disc Brake Master Cylinder Kit “Lever Latch” with gasket and
fluid baffle, includes: master cylinder and cap, 4 mounting screws
with washers, 2 rollers with matching nuts and bolts
1A 47268K Drum Brake Master Cylinder Kit “Lever Latch” with gasket and
fluid baffle, includes: master cylinder and cap, 4 mounting screws
with washers, 2 rollers with matching nuts and bolts
1B 11253A Disc Brake Solenoid, Back Flow Model with return hose
1C 48803 Gasket, for “Lever Latch” 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 16020 and below)
3 50305 Emergency Stop Cable (E-stop/Breakaway),
(serial numbers 16021 and above)
4 50301 Safety Cable with stainless steel pin - with mounting screw
5 47264 Actuator Covers, Includes front and rear cover plates and
4 mounting screws
6 48804 Master Cylinder Fill Cap with internal bladder
7 48845 Safety Spring with two mounting screws,
(for serial numbers 16021 and above)
Model 70 - 7,000 lbs. Capacity
Part #47204 Disc Brake - Lever Latch
Part #47213 Disc Brake - Lever Latch
Part #47205 Disc Brake - Lever Latch
Part #47203 Disc Brake - Lever Latch
Part #47202 Drum Brake - Lever Latch

Limited Warranty TIE DOWN ENGINEERING (“TIE DOWN”) warrants its products to be
free from defects in material and workmanship for one year from date of delivery to the
original purchaser when properly installed, used and maintained by the purchaser.
This warranty does not apply to damage or loss caused by any or all of the following
circumstances or conditions:
• Damage caused during installation.
• Parts, accessories, materials or components used with or replacing any TIE DOWN
braking system not obtained from or approved in writing by TIE DOWN.
• Misapplication, misuse and failure to follow the directions or observe cautions and
warnings on installation, operation, application, inspection or maintenance specified
in any TIE DOWN quotation, acknowledgment, sales literature, specification sheet or
installation instruction and service manual (“applicable literature”).
• Use of product in any other application other than those described in TIE DOWN
product information materials.
If any TIE DOWN products are found upon TIE DOWNS examination to have been
defective when supplied, TIE DOWN will either: credit the purchaser’s account for the
purchase price of the TIE DOWN product; 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 defect within
30 days of either the discovery of the alleged defect or the expiration of the warranty
period, whichever is earlier. Any claim not made within this period shall conclusively be
deemed waived.
If requested by TIE DOWN, purchaser shall return the alleged defective product to
TIE DOWN for examination at purchasers expense. TIE DOWN will not pay for expenses
incurred in returning a product to TIE DOWN without TIE DOWNS prior written authority.
TIE DOWN shall not be liable for any other expenses purchaser incurs to remedy any
defect. Purchasers waive subjugations on all claims under any insurance.
Limitation of Liability: It is expressly agreed that the liability of TIE DOWN is
limited and TIE DOWN does not function as an insurer. THE REMEDIES SET FORTH
IN THIS WARRANTY SHALL CONSTITUTE THE EXCLUSIVE REMEDIES AVAILABLE TO
THE PURCHASER OR USER AND ARE IN LIEU OF ALL OTHER REMEDIES, EXPRESS OR
IMPLIED. THE LIABILITY OF TIE DOWN, WHETHER IN CONTRACT, IN TORT, UNDER
ANY WARRANTY OR OTHERWISE, SHALL NOT EXCEED THE PURCHASE PRICE OF THE
PARTICULAR PRODUCT MANUFACTURED, SOLD OR SUPPLIED BY TIE DOWN.
TIE DOWN ENGINEERING LIMITED WARRANTY
Page 13

To Obtain Technical Assistance: To enable TIE DOWN to respond to a request for
assistance or evaluation of customer or user operating difficulty, please provide at a
minimum the following information by calling 1-800-241-1806:
• Model number, serial number and all other data on the specific component which
appears to be involved in the difficulty.
• The date and from whom you purchased your TIE DOWN product.
• State your difficulty, being sure to mention at least the following: Application,
Nature of load involved, and Weight of the load.
Field Service: If field service at the request of the purchaser is rendered and the
difficulty is found not to be with TIE DOWNS product, the purchaser shall pay the time and
expense (at the prevailing rate at the time of service) of seller’s field representative(s).
Charges for service, labor and other expenses that have been incurred by the purchaser,
its customer or agent without prior written authorization of TIE DOWN will not be accepted.
TIE DOWN EXTENDS NO WARRANTY, EXPRESS OR IMPLIED, ON PRODUCTS NOT
MANUFACTURED BY TIE DOWN OR TO TIE DOWNS DESIGN SPECIFICATION, INCLUDING
BUT NOT LIMITED TO SUCH ITEMS AS NON-TIE DOWN TIRES, BRAKES, 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
FITNESS FOR A PARTICULAR PURPOSE OR ANY PURPOSE.
THIS WARRANTY DOES NOT COVER NOR EXTEND TO INCIDENTAL OR
CONSEQUENTIAL DAMAGE. Some states do not allow the exclusion or limitation of
incidental or consequential damages, so the above limitation or exclusion may not apply
to you. This warranty gives you specific legal rights, and you may also have other rights
which vary from state to state.
No representative has authority to make any representation, promise or agreement
except as stated in this Limited Warranty. TIE DOWN reserves the right to make design and
other changes upon its products without any obligation to install the same on any
previously sold or delivered products.
DUE TO THE WIDE VARIATION IN USES TO WHICH TIE DOWN PRODUCTS (WHEELS,
HUBS, BRAKES, ETC.) ARE SUBJECTED BY USERS, WE ARE UNABLE TO SPECIFY
CARRYING CAPACITIES OR SPEEDS FOR A PARTICULAR APPLICATION. THEREFORE,
THE MANUFACTURER MUST TEST HIS EQUIPMENT UNDER THE MOST SEVERE
CONDITIONS TO DETERMINE THAT TIE DOWN PRODUCTS ARE SUITABLE.
THERE ARE NO WARRANTIES WHICH EXTEND BEYOND THOSE DESCRIBED ABOVE.
EFFECTIVE JANUARY 2013 THIS WARRANTY SUPERSEDES ALL PRIOR WARRANTIES,
WRITTEN OR IMPLIED.
Page 14

TIE DOWN ENGINEERING
www.tiedown.com
255 Villanova Drive SW, Atlanta, GA 30336
[phone] • Fax [phone]
© 2014 TIE DOWN Inc., ALL RIGHTS RESERVED
Instruction #08164-2
Model 750E
Brake Actuator
Owners Manual
051214,C1257