Volvo VHD Automobile User Manual


 
242 Brakes
Jake-Brake Or C-Brake
The Jake-Brake or C-Brake is optional
equipment for Cummins, and Detroit en-
gines. These engine brakes are similar in
operation. Three power levels are available
by engaging 2, 4, or 6 cylinders when brak-
ing (for Cummins M11, only two power
levels are available).
It is operated by two switches in the right
hand switch cluster. It works together with
the exhaust brake to provide two levels of
braking power. The left switch is the
ON/OFF switch. The desired braking power
is selected with the right switch which has
three positions: LOW, MED and HIGH (for
Cummins M11, only LOW and HIGH).
For the exhaust brake to function, the fol-
lowing must be in effect:
The switch is ON
Vehicle speed over 7.5 mph (12 km/h)
Engine temperature over 110
F (43 C)
Accelerator and clutch pedals fully re-
leased
Engine speed exceeding 1100 r/min
When the cruise control is engaged, the ex-
haust brake automatically engages if the
selected cruise speed is exceeded by ap-
proximately 5 mph (8 km/h). The exhaust
brake is then disengaged when the speed
has returned to approximately 3 mph
(5 km/h) above the selected cruise speed.
For more information, read the Jake-Brake
or C-Brake operator’s manual.
W3002303