Ford F-650 2018, Owner'S Manual

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Parking Brake Light Illumination Due
to Low Air Pressure
If the air pressure becomes too low at any
time during vehicle operation, the parking
brake may apply and the parking brake
light turns on.
If the parking brake applies due to low air
pressure, immediate service is required to
the parking brake system.
Releasing Spring Brake with Air
Pressure
The air system in all vehicles with
spring-actuated rear wheel parking brakes
has a valve on the governor for connection
to an outside air supply. The valve lets you
recharge the system with air from an
outside source, releasing the
spring-actuated parking brakes. Your
vehicle is now ready to tow in an
emergency.
You can only use an outside air source if
the protected system is in operating
condition. If you cannot restore air pressure
in the protected air system, you must
release the spring-actuated brakes
manually.
Releasing Spring Manually
Do not use impact wrenches as they may
damage the piston and prevent proper
caging of the spring. Do not apply more
than 50 lb.ft (68 Nm) to the release bolt
nut.
1. Remove the stud tool and nut from the
carrying pocket on the brake chamber
assembly.
E210365
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.
E210366
4. Turn the release stud ¼ 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 brakes released. Do not
loosen or remove the release stud and
nut unless you completely assemble
and securely clamp the brake chamber.
6. After restoring the air pressure,
unscrew and remove the release stud
and install in the carrying pocket. Install
the access plug.
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F650750 (TBC) , enUSA, Edition date: 201708, First Printing
Brakes