Figure 5-30. Secondary Fuel Filter
Section IX. ENGINE RETARDER SYSTEM
gases, causing a pressure rise In the exhaust manifold.
The engine retarder systems are
This pressure increase can vary from 30 to 40 psi
used on many larger vehicles equipped with diesel
(206.85 to 275.8 kPa). The compression brake causes
They are designed to provide additional
a pressure buildup in the cylinder during the exhaust
stopping ability to a vehicle in motion. These systems
stroke. The engine then becomes a low-pressure pump
also relieve the service brakes of excessive heat buildup
driven by the wheels.
This, In turn, slows down or
and wear due to prolonged application.
retards the vehicle.
means of power absorption Is used to accomplish the
additional braking process.
Basically, three different
5-39. Hydraulic Retarder. The hydraulic retarder Is a
engine retarder systems currently are used; each Is
pedal-operated unit mounted in the transmission. This
system assists the service brakes in controlling the
vehicle's speed during long down-hill braking or when
5-38. Compression Brake. The compression brake
slowing down In stop-and-go traffic.
operates by restricting the exhaust gas flowing from the
consists of a retarder cavity located between the
The system basically consists of a butterfly
converter and transmission
valve fitted into the exhaust pipe between the exhaust
manifold and muffler. The system Is activated by a
switch mounted in the cab. The valve is controlled by
an air or vacuum switch mounted on the accelerator
pedal. The system operates by restricting the exhaust