Ford F-650/750 (2018 year). Manual — part 31

TRAILER BRAKES

(If Equipped)

Trailer Brake Hand Control

(If Equipped)

WARNING

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.

E210339

The hand control is located on the
right-hand side of the instrument panel. It
applies the trailer service brakes, which are
independent of the truck or tractor service
brakes.

It operates a valve that provides gradual
control of air pressure applied. When the
valve is only partially applied, you can
override the trailer brakes by pressing fully
on the brake pedal.

To apply the trailer brakes using the hand
control, move the lever downward. The
further you push the lever down, the
greater the air pressure is applied to the
brakes. The lever remains in place until
manually moved.

To release the trailer brakes, move the
lever up completely.

Trailer Air Supply and Parking
Brake Modular Controls

(If Equipped)

E210340

A

B

1

2

A

3

20

A

The trailer air supply valve delivers air to
the trailer supply and automatically pops
out, shutting off the trailer supply, if
pressure decreases to approximately 35 psi
(249 kPa).

E210341

The parking brake controls the spring
brakes on the tractor. When you pull the
knob out, it causes the trailer supply valve
to pop out, applying both the tractor and
trailer parking brakes. You can
independently release the trailer brakes by
pushing only the trailer air supply valve in.

Initial Charge

E210342

With the air system completely discharged,
both knobs (A and B) are out. When the
air pressure reaches 70 psi (481 kPa), the
trailer air supply (A - red knob) may be
pushed in and should stay in, charging the
trailer air system and releasing the trailer
brakes.

E210343

You can push in the parking brake (B -
yellow knob) and supply air to the tractor
spring brakes, releasing them.

Normal Driving Position

E210343

Push in both knobs (A and B) to supply air
to both trailer and tractor spring brakes,
releasing all brakes.

System Park

E210344

With both knobs (A and B) pushed in
(normal driving position), the parking
brakes for both the tractor and trailer can
be applied by pulling the parking brake
knob (B) out, exhausting air from the
tractor spring brakes, simultaneously
causing the trailer air supply valve to pop
out, applying the trailer brakes.

Trailer Charge

E210342

If both knobs (A and B) are out, and you
want to recharge the trailer while leaving
the tractor spring brakes applied, the trailer
air supply (A) can be pushed in to recharge
the trailer air supply line. You can also use
this mode to park a combination vehicle
with tractor spring brakes.

Automatic Application

E210345

If both knobs (A and B) are pushed in and
the brake system air pressure is reduced
to approximately 35 psi (249 kPa), the
trailer air supply (A) knob automatically
pops out applying the emergency or
parking brakes on the trailer. If the trailer
air supply (A) knob is manually held in and
the air pressure is reduced to
approximately 30 psi (207 kPa), a tripper
piston within the valve moves, exhausting
the trailer air supply, applying the trailer
brakes. Further reduction of air pressure,
while holding the trailer air supply knob in,
causes the parking brake knob to pop out
at 25 psi (172 kPa).

Actuation of Trailer Park (Emergency)
or Tractor Bobtail Position

E210345

To actuate the trailer brakes only, pull out
the trailer air supply (A) knob. This applies
the trailer brakes whether the trailer uses
emergency or spring brakes.

You can also use this mode when the
tractor or truck with trailer is used during
bobtail operation.