Volvo EPA2007 D13F Reference Manual page 109

ENGINE COMPONENT AND LOCATION 103
When the accelerator pedal is released (and the Volvo Engine Brake switch is ON),
the solenoid opens allowing some oil to escape through a small port. Reduced spring
pressure moves the piston, opens the passage to the rocker shaft and increases the oil
pressure. The system opens the exhaust valve during induction and again immediately
before TDC on the compression stroke.
The engine slows because the extra volume under compression takes more power to
compress, and escaping pressure in the combustion stroke reduces the power output.
A switch on the instrument panel allows the driver to engage or disengage Volvo
Engine Brake.
If the ABS system becomes active, it automatically disables Volvo Engine Brake.If the
oil temperature goes below 55°C (131°F), Volvo Engine Brake cannot be activated.
A warning lamp on the instrument panel flashes if the driver attempts to activate
it under this condition.
A port in the cylinder head allows access to the oil passageway. The plug can be
removed and a gauge inserted for use during diagnostic procedures.
Engine Speed/RPM
600
>1100
>1100
Rocker Shaft Engine Brake
Active
Inactive
System Oil Pressure
Temperature
90 – 110°C (195 – 230°F)
90 – 110°C (195 – 230°F)
Cold Engine
Engine Speed/RPM
900 — 2300
—
Pressure
>250 kPa (>36 psi)
300 – 550 kPa (44– 80 psi)
650 kPa (95 psi)
Oil Pressure
220 kPa (32 psi)
80 — 120 kPa (12 — 17
psi)