Engine Brake Control - Navistar International DT 466 Diagnostic/Troubleshooting Manual

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driving conditions. See vehicle Operator's Manual for
complete operating instructions.
Engine Brake Concept
The engine brake system retards vehicle speed
during deceleration or braking. During deceleration
and braking, the vehicle wheels drive the engine; the
engine acts as an energy absorber.
Engine Brake Operation
To absorb energy, the Diamond Logic® engine brake
combines bleeding off compressed intake air, VGT
controlling exhaust back pressure, and vehicle driven
piston movement.
• Energy is absorbed during the compression
stroke, when intake air is compressed and forced
through a slightly open exhaust valve, providing
compressed air flow to the VGT.
• VGT turbine vanes create the desired energy
absorbing, back pressure and intake boost.
• At the top of the compression stroke energy
dissipates, pressure to force the piston down is
eliminated, and energy is absorbed by the vehicle
drive pulling the piston down.
Read all safety instructions in the "Safety Information" section of this manual before doing any procedures.
1 ENGINE SYSTEMS

Engine Brake Control

Figure 46 High-pressure oil rail
1.
2.
3.
4.
5.
6.
The high-pressure oil rail uses high-pressure oil from
the injection control pressure system to open exhaust
valves.
EGES-270-1
Follow all warnings, cautions, and notes.
© August 2008 Navistar, Inc.
High-pressure oil rail
ICP sensor
Brake shut-off valve assembly
BCP sensor
Brake pressure relief valve
Front of engine