2006 FORD F750 engine

road dust, salt or mud. If a “metal-to-metal,” “continuous grinding” or
“continuous squeal” sound is present while braking, the brake linings
may be worn-out and should be inspected by a qualified service
technician.
Know the required stopping distances for all driving conditions that may
be encountered. For longer brake lining life, take full advantage of engine
braking power when coming to a stop.
Do not drive with your foot resting on the brake pedal. This will
result in abnormally high brake temperatures, excessive lining
wear and increased stopping distances.
Before descending a long or steep hill, shift to a lower gear and avoid
continuous application of the brakes. Normally, choose the same gear to
descend the hill that you would use to ascend the hill.
Continuous application of the brakes will cause the brakes to
overheat, resulting in a temporary loss of braking.
If brakes do not grip well
•If you have been driving through deep water, gently apply the brakes
several times while the vehicle is moving slowly.
•Let the brakes cool if you have been using them excessively, as in
mountain driving or after several fast, high speed stops.
•Check brake adjustment.
•Check brake linings for excessive wear.
•Check system air pressure. (Air brakes only)
HYDRAULIC BRAKES (IF EQUIPPED)
HydroMax brake booster system
The HydroMax systems receive fluid pressure from the power steering
pump to provide power assist during braking.
The HydroMax booster receives back-up pressure from the reserve
system electric pump whenever the fluid in the power steering system is
not flowing. When the engine is off, the pump will turn on if the brake
pedal is applied, or if the ignition is turned to the ON position.
The sound of the pump operating or fluid flowing through the booster
may be heard; this is a normal characteristic of the system and should be
no reason for concern.
2006 F-650/750(f67)
Supplement
USA(fus)
Driving
98

The reserve system provides reduced braking power, so the vehicle
should be operated under these conditions with caution, and only to seek
service repair and remove the vehicle from the roadway.
If braking performance or pedal response becomes very poor, even when
the pedal is strongly applied, this may indicate the presence of air in the
hydraulic system or fluid leakage. Stop the vehicle safely as soon as
possible and seek service immediately.
If the red BRAKE warning lamp in
the instrument cluster remains
illuminated after engine start up,
this indicates a system failure in the
master cylinder of the brake system. Stop the vehicle safely as soon as
possible and seek service immediately.
If the yellow BRAKE RESERVE
(E-motor) warning light remains on
while the engine is running, this
indicates inadequate hydraulic
booster pressure or reserve pump
system failure. Stop the vehicle safely as soon as possible and seek
service immediately.
BRAKE
2006 F-650/750(f67)
Supplement
USA(fus)
Driving
99

Releasing the parking brake
Note:Read and understand the following steps and perform them
whenever you prepare to drive the vehicle.
Note:The parking brake will not disengage unless sufficient system air
pressure is available.
For vehicles with automatic transmissions - dash-mounted push
button (Allison 3000 Series) and steering column-mounted (Allison
2200 and 2500) gear selection:
1. With the engine running, depress and hold the service brake pedal.
2. Wait until system air pressure is above 100 psi (690 kPa).
3. Select the appropriate drive gear.
4. Push the yellow, dash-mounted parking brake knob.
For vehicles with manual transmissions - (TTC 7–speed,
Eaton/Fuller 5–speed, 6–speed and 10–speed):
1. With the engine running, depress and hold the service brake pedal.
2. Wait until system air pressure is above 100 psi (690 kPa).
3. Depress and hold the clutch pedal.
4. Select the appropriate drive gear.
5. Push the yellow, dash-mounted parking brake knob.
Hold the brake pedal down while moving the gearshift lever from
position to position. If the brake pedal is not held down, the
vehicle may move unexpectedly resulting in property damage, personal
injury or death.
Parking brake light illumination due to low air pressure
If at any time during vehicle operation air pressure is too low, the
parking brake may apply and the parking brake light will turn on.
If the parking brake is applied due to low air pressure, immediate service
is required to the parking brake system.
Parking brake warning system
If the park brake light blinks and a chime sounds when pulling the yellow
control knob out, this indicates the parking brake is not functioning
properly; seek service for the parking brake immediately.
The light will blink and the chime will sound until the yellow control
knob is pushed in or approximately eight minutes have passed. If the
2006 F-650/750(f67)
Supplement
USA(fus)
Driving
102

AIR BRAKES (IF EQUIPPED)
General air brake information
After starting the engine, give the air compressor time to build up the air
pressure to 60 psi (414 kPa) before moving the vehicle.
Do not drive or continue to drive if the low air pressure buzzer
is sounding or the brake warning light is lit. These warnings
indicate that air pressure is not to normal operating level. Continued
use of the vehicle could result in loss of braking ability.
Avoid repeated light application of the brake pedal. This will
deplete air pressure faster and could result in loss of braking
capability.
Periodically check the air pressure
gauge while driving. Pressure should
range between approximately
100–125 psi (690–862 kPa). The air
compressor governor cut-in and
cut-out pressure settings are preset
at the factory and are not
adjustable.
When air pressure is insufficient
(below 60 psi [414 kPa]), a warning
light illuminates and a buzzer
sounds when the ignition is in the
ON position.
This condition may be caused by excessive brake applications depleting
the system air pressure. If this condition occurs, stop driving the vehicle
until the compressor has fully recharged the air system.
Do not move the vehicle when the air perssure is insufficient
because the brake system may be inoperative.
Select a gear ratio to help slow your vehicle before descending grades.
Supplement with brakes as required to safely slow the vehicle and avoid
overspeeding the engine.
0 30 12090 60
150AIR
PRESSUREPSI
2006 F-650/750(f67)
Supplement
USA(fus)
Driving
104

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.
EXHAUST BRAKE (IF EQUIPPED)
Note:The exhaust brake is a
retarding device intended to help
control vehicle speed; it is not a
vehicle stopping device.
An exhaust brake is an optional
auxiliary braking system that assists,
but does not replace, the primary
service brake system. An on-off
switch on the instrument panel, in
combination with the accelerator
and clutch pedal switches, allows the operator to make maximum use of
the exhaust brake in the following conditions:
•off-highway driving
•mountain driving
•heavy traffic
•high speed highway driving
Note:The exhaust brake should be turned off when the engine is left
idling for an extended period of time (longer than three minutes).
2006 F-650/750(f67)
Supplement
USA(fus)
Driving
109

The exhaust brake is a butterfly
type valve mounted in the exhaust
pipe. When the operator’s foot is not
on the accelerator pedal and the
exhaust brake switch is in the ON
position, an air cylinder shuts the
butterfly valve, restricting the flow
of exhaust gases and retarding the
engine. This retarding action is
carried through the engine and drivetrain, slowing the vehicle and
reducing the need for frequent service brake applications.
Exhaust brakes are not intended for use as the primary braking system
during vehicle operation.
Operation
Push the rocker switch up to turn
the exhaust brake on. The switch
will illuminate in the ON position.
Push the switch down to turn the
brake off.
Starting engine
Before starting the engine, make sure that the exhaust brake switch is in
the OFF position. Do not turn the exhaust brake on until the engine has
reached normal operating temperatures.
Driving downhill
While approaching a steep grade, make sure that the exhaust brake
switch is in the ON position. The exhaust brake actuates as soon as you
remove your foot from the accelerator pedal. While going down the
grade, use a low enough gear to descend safely with a minimum
application of the service brakes. As a general guideline, use the same
gear as you would to ascend the hill.
Before descending a hill or steep grade always select the proper gear. If
the transmission is taken out of gear while descending it is possible that
you will not be able to select another gear because of maximum RPM
being governed.
2006 F-650/750(f67)
Supplement
USA(fus)
Driving
110

Note:Maximum exhaust brake performance is related to the type of
transmission your vehicle is equipped with.
Note:Manual transmissions should be downshifted to the lowest gear
possible, without exceeding the maximum RPM limit of the engine. This
will maximize the exhaust brake’s retarding effect.
Note:Exhaust brakes will operate effectively with automatic
transmission, but performance will vary with engine speed and the gear
selected by the transmission.
Make sure the engine speed does not exceed the maximum allowable
engine RPM. Exceeding the maximum allowable engine RPM will result
in damage to the engine. Apply the service brakes to reduce the engine
RPM or make a slower descent by using a lower gear.
Note:Engine speed has a major influence of retarding performance.
When engine speed is maintained at the maximum allowable level, the
exhaust brake will operate at peak performance.
The exhaust brake is not recommended for use on slippery or
low traction road surfaces. Under these conditions a loss of
vehicle control could occur.
Exhaust brake operating characteristics
When you remove your feet from both the accelerator and clutch pedals
and the exhaust brake switch is in the ON position, the exhaust brake is
activated. The following conditions should exist if the brake is operating
properly:
•A slight change in the sound of the engine when the exhaust brake is
activated.
•Exhaust smoke appears normal.
•Engine temperature remains in the normal operating range.
•Road speed usually decreases when the exhaust brake is applied
during a descent, except when the vehicle is carrying a heavy load or
the grade is extremely steep. In these instances, you may need to
apply the service brakes occasionally.
•During a descent, the tachometer usually shows a drop in RPM
depending on the grade and the vehicle load.
•Do not expect a retarding effect similar to sudden hard application of
the service brakes. The exhaust brake retards the vehicle with a
smooth braking effect.
2006 F-650/750(f67)
Supplement
USA(fus)
Driving
111

•Depending on the grade and vehicle load, you may or may not feel the
retarding force acting against your body when the brake is applied.
The brake’s retarding force is actually preventing the vehicle from
going much faster.
•Engine speed has a major effect on retarding performance, with higher
engine speeds permitting greater retarding ability.
•Engine brake performance is closely related to the type of
transmission your vehicle is equipped with. Downshifting of manual
transmission to the lowest gear possible, without exceeding the
maximum engine RPM limit, will maximize retarding performance.
Exhaust brakes will operate effectively with automatic transmissions,
but performance will vary with engine speed and the gear selected by
the transmission.
Make sure the exhaust brake is turned off before shutting off the engine.
Note:Installing an exhaust or auxiliary brake does not necessarily
protect the engine from exceeding maximum governed speed. The
primary brakes should be used to never allow the engine to exceed
maximum governed speed under any conditions.
TRAILER BRAKE HAND CONTROL (IF EQUIPPED)
The hand control, located on the
right-hand side of the instrument
panel, is used to apply the trailer
service brakes which are
independent of the truck or tractor
service brakes.
The hand control should
never be used to apply the
brakes when the tractor and
trailer are parked unattended. Air
may leak from the system and the
vehicle could possibly move,
resulting in possible property
damage, personal injury or death.
The hand control operates a valve that provides gradual control of air
pressure applied; when the valve is only partially applied, the trailer
brakes can be overridden by pressing fully on the brake pedal.
2006 F-650/750(f67)
Supplement
USA(fus)
Driving
112