atwood Hydraulic Brake Surges - Manual (Page 3)

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6,000 LB. ACTUATORS are not equipped with a solenoid back-up valve. When a
solenoid back-up valve is desired please contact Atwood for the solenoid back-
up valve kit. Atwood Mobile Products 866-869-3118.
To install Atwood solenoid back-up valve -
1. Remove the plug in return port of master cylinder (this is the upper port in
the master cylinder).
2. Install straight barbed fitting (torque to 16-20 in/lb).
3. Install assembly in supply port of master cylinder (this is the lower port in
the master cylinder).
4. Connect the solenoid wire leads only into the reverse back-up light circuit.
5. Connect trailer brake line to actuator.
6. Bleed brake system
FOR DISC BRAKE SYSTEMS
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CAUTION
DAMAGE TO BRAKE ACTUATOR OR VEHICLE
• If brass orifice fitting is not installed ( FIG 10B), trailer-braking action may
cause vehicle(s) to shake during brake applications.
The brass orifice fitting installed in master cylinder ( FIG 10A) of brake actuator
assembly must remain in hydraulic circuit to brakes ( FIG 10C) of trailer.
If brass orifice fitting must be moved to accommodate plumbing ( FIG 10E) for a back up
solenoid valve ( FIG 10D), it must be replaced in hydraulic circuit in line to brakes.
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WARNING
DEATH OR PERSONAL INJURY
• Contaminated brake fluid in system could plug brass orifice fitting. This
could render brakes inoperative.
Be especially careful to clean all fittings, tubing and threads between master
cylinder and brass orifice fitting. A very small particle of dirt or thread sealant
can plug hole in orifice.
• Do not use Teflon ® tape on fittings.
• If a liquid or paste thread sealant is used, keep it back two threads from end
of male fitting.
• Do not apply sealant to female threads. Clean female threads thoroughly.
BLEED BRAKE SYSTEM
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CAUTION
BRAKE FAILURE
• DO NOT use brake fluid drained from brake system in refilling master cylinder.
Brake fluid can be contaminated from the system.
1. Remove master cylinder filler cap and fill reservoir with DOT type 3 or 4
automotive brake fluid.
2. Check all hydraulic line fittings & connections to make sure they are leak free.
3. At brake assembly, connect a bleeder hose to bleeder fitting on wheel cylinder
and submerge free end in a container with brake fluid. DO NOT reuse brake fluid.
NOTE : Use power bleeder or bar with 2˝ diameter hitch ball attached ( FIG 9).
Do not use breakaway cable for purpose of bleeding brake system. If a power
bleeder is used air pressure 35 PSI is most effective.
NOTE : Bleed brakes on rear most axle furthest from the actuator first.
4. Loosen bleeder fitting at top of brake assembly.
5. Apply actuator (see
FIG 9) and tighten bleeder fitting. Return actuator to for-
ward position. Again, loosen bleeder valve one turn and apply actuator.
Repeat this procedure until fluid expelled from bleeder hose is free of air bub-
bles. It is helpful to lower the trailer tongue to promote air bubble movement
in the brake tubing. It is also helpful to tap gently along the brake tubing dur-
ing brake bleeding to keep air bubbles from sticking to the inside of the brake
tubing. During this procedure, master cylinder reservoir fluid level must be
maintained at no less than 1/2 full and no more than 1/2˝ from top of reser-
voir.
6. When no air bubbles are visible, close bleeder valve securely and remove
bleeder hose.
7. Repeat STEP 1-6 for remaining brake, then brakes on forward axle.
8. If installation is tandem axle with brakes on both axle, repeat bleeding proce-
dure on rear axle brakes for second time to assure positive purging of all air
in system.
9. After bleeding has been completed, re-check fluid level in master cylinder.
OPERATION - TOWING
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CAUTION
TRAILER MAY DISCONNECT
• Release handle ( FIG 12A) must be fully closed before towing.
• Do not force release handle into closed position.
1. Position actuator ball socket above 2˝ ball.
NOTE : Do not damage actuator when backing up towing vehicle for hook-up.
2. Hold release handle in open position ( FIG 11A). Release handle must be held
in fully open position to remove from or place on ball.
3. Lower trailer tongue until ball rests in ball socket.
4. Close release handle (
FIG 12A). Release handle will close freely with finger
pressure when ball is properly inserted into ball socket.
5. To make sure actuator is securely latched onto ball, extend trailer tongue
jack to ground and lift car and trailer combination 2˝ to 4˝. If ball does not
disengage, actuator is securely attached.
6. Insert padlock or bolt through lock hole for theft protection.
7. Connect breakaway cable solidly to bumper or frame of tow vehicle as near to
center as possible. Cable must hang clear of trailer tongue and long enough to
permit short radius turns without pulling breakaway cable forward.
8. Make sure breakaway cable ( FIG 13C) is in released position with indicator
bead ( FIG 13B) touching or resting against cable spring stop ( FIG 13A).
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CAUTION
PRODUCT DAMAGE
• DO NOT use breakaway cable as a parking brake.
NOTE : Check location of breakaway cable periodically during each trip, indicator
should rest against spring stop. Accidental application will cause brakes to drag
and heat up, causing failure.
9. Cross safety chains under tongue & securely attach to bumper or frame of tow vehicle.
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CAUTION
TRAILER DAMAGE
• Safety chains must be used.
10. Retract jack fully. Remove and store caster, if applicable.
11. Check for proper car-trailer hook-up: tow vehicle and trailer should be level
with positive tongue load. For further information, consult a dealer or
Atwood Service Department.
12. Back-up lever knob must be positioned in TOWING POSITION ( FIG 15-A).
13. If actuator is used with equalizing hitch, be sure hanger chains ( FIG 14D)
hang between straight down and forward up to 34° ( FIG 14C). DO NOT use less
than 6-1/2˝ hanger chain length ( FIG 14x). For optimum brake performance,
hang chains forward 34° ( FIG 14).
14. DO NOT use Atwood brake actuator with a sway controller, unless prior
Atwood Engineering approval of sway control system has been received.
15. You are now ready to tow your vehicle.
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CAUTION
PRODUCT & TRAILER DAMAGE
• Avoid sharp turns. This could bend, create extreme stress or fracture either
actuator or trailer tongue.
BACKING UP
1. Follow step 1 through 15 for TOWING .
2. If equipped with solenoid valves skip to STEP 5.
3. Before backing up a slope or through soft ground, pull trailer forward slight-
ly to assure actuator socket is in fully forward position.
4 Move lever knob on side of actuator downward from TOWING POSITION ( FIG 15A)
along curved slot in actuator frame to BACK - UP POSITION ( FIG 15B). Slot has a
notch at bottom of its travel. Push lever knob down to engage locking notch.
5. Back trailer up.
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CAUTION
PRODUCT & TRAILER DAMAGE
• Avoid sharp turns. This could bend, create extreme stress or fracture either
actuator or trailer tongue.
6. If trailer is to be uncoupled from tow vehicle after backing with lever knob
engaged, block all trailer wheels and pull forward slightly to take strain off
actuator. Uncouple actuator by lifting release handle and raising trailer
tongue. Make sure lever knob is in
TOWING POSITION ( FIG 15A) when uncou-
pling from trailer.