Ford F-650 2015 Owner's Manual page 149

148
System Park
B
A
With both knobs 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
If both knobs 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.
2015 F-650/750 (f67)
Owners Guide gf, 2nd Printing, April 2014
USA (fus)
Brakes
B
A
B
A
B
A
B
A