Block the wheels to prevent the vehicle from moving.
Unexpected and possibly sudden vehicle movement may occur if
these precautions are not taken.
Impact wrenches should not be used as they may damage the piston and
prevent proper caging of the spring. Do not apply more than 68 Nm
(50 lb-ft) torque to the release bolt nut.
1. Remove the stud tool and nut
from the carrying pocket on the
brake chamber assembly.
2. Remove the access plug from the
end of the spring chamber.
3. Insert the release stud through
the opening in the chamber and into
the spring pressure plate.
4. Turn the release stud one-quarter
turn to engage the stud tangs with
the slot in the pressure plate. Keep
the stud engaged and install the nut
on the release stud.
5. Tighten the nut until the spring is
fully caged and the brakes are
released. Do not loosen or remove
the release stud and nut unless the brake chamber is completely
assembled and is securely clamped.
6. When the air pressure is restored, unscrew and remove the release
stud and install in the carrying pocket. Install the access plug.
Trailer brake (if equipped)
During normal operation, the trailer brakes operate whenever the tractor
brakes are applied. A manual control lever is provided so the trailer
brakes can be applied separately, if required. To apply the trailer brakes,
pull the trailer brake control downward to the APPLIED position.
Driving
118
SERVICING YOUR WHEELS AND TIRES
Wheel assembly
Your vehicle is fitted with hub
piloted wheels and two-element
swiveling lug nuts (20 & 22 mm).
Do not use taper type wheels or ball
seat wheel nuts.
²Do not paint the mating face of the hub/drum.
²Do not paint the two-element swiveling lug nuts or wheel stud.
²Do not allow an excessive thickness of paint to build between the disc
wheel mounting surfaces.
²Do not install disc wheels where the paint has not fully cured.
²At wheel changes, ensure mounting faces are clean and free of rust,
dirt and excess paint.
If fasteners are needed, use only Ford recommended replacement parts.
²To maintain the desired
torque/tension relation between
nut body and flange, it is
necessary to use clean engine oil
meeting Ford specification
WSS-M2C153-G between nut body and flange. Lubricate the nut body
and flange any time a wheel is removed.
The M20 & M22 wheel nuts are right-hand threads. Refer to the
following chart for approved wheel lug nut torque.
Wheel type Bolt size Wheel nut torque
10-hole disc
285.75 mm bolt circleM22 (22 by 1.5 mm) 610-677 Nm
(450-500 lb-ft)
8-hole disc
19.5x6.75 mm bolt
circleM20 (20 by 1.5 mm)
610-677 Nm
(450-500 lb-ft)
The disc wheel nuts on your vehicle were tightened before delivery.
Recheck torque of nuts at 160 km (100 miles) and 800 km (500 miles) of
new vehicle operation or any time a wheel is removed. Reset to
recommended torque levels.
Maintenance and care
179
