Hooking Up/Unhooking; Hooking Up - Midland SIDE DUMP GRAVEL TRAILER Operator's Manual

4.6

HOOKING UP/UNHOOKING

Special care should be taken when hooking up
or unhooking trailer to be sure the equipment
is in good condition and all systems are
functioning as required.
4.6.1

HOOKING UP

Follow this procedure when hooking up the
trailer to towing vehicle (tractor or lead trailer):
1. Back the towing vehicle up in a straight
line to the trailer and align the fifth wheel
opening with the trailer king pin.
2. Stop before the fifth wheel makes contact
with the trailer and apply the towing
vehicle parking brake.
3. Inspect all the coupling components
before hooking up:
a. Inspect trailer coupling components.
Check that king pin is not broken, bent
or chipped. Check that the king pin
mounting frame is not bent or cracked.
If problems found, correct before
proceeding.
b. Inspect fifth wheel coupling
components. Check that the fifth
wheel assembly is securely anchored
to the tractor frame. Check that the
structure of the frame, pivot and fifth
wheel is not bent, broken or cracked.
Check that the jaws of the lock are
open. If problems found, correct before
proceeding.
c. Be sure that the fifth wheel plate is cleaned
and greased.
4. Open the coupler lock.
5. Tilt the fifth wheel plate back.
6. Check that the trailer is at the required height to
slide onto the fifth wheel.
a. Use the crank on the landing gear to raise or
lower the trailer as required.
b. On drop leg landing gear, care must be taken
if the trailer is too low to climb up on the 5th
wheel. It may be necessary to raise the trailer
and repin the drop legs.
The trailer frame should contact the fifth wheel
just behind the pivot point as the towing unit
backs under the trailer.
Fig. 9 COUPLING COMPONENTS
7. Block the trailer wheels.
8. Connect brake lines. Route the lines so they do
not get pinched when the trailer is attached to the
tow unit.
9. Check brake application by applying and
releasing brakes. If brakes do not release, air
lines may be crossed. Do not continue unless
brakes are functioning properly.
10. Re-apply trailer brakes using trailer hand valve.
King Pin
Fifth Wheel
21