Holiday Neptune 2004, Owner'S Manual

Page: 390 / 416

390 • SECTION 10 --- CHASSIS INFORMATION NEPTUNE 2004
After leaving the turbocharger, intake air is compressed and heated to
approximately 300º to 375º F., depending on the engine load and throttle position.
Before the air enters the intake manifold, the CAC cools the intake air temperature
to the engine manufacturer's specifications. Lower intake air temperatures
reduce exhaust emissions, improve fuel economy and increase horsepower. The
CAC will continually expand and contract up to ¼ inch as throttle increases and
decreases.
Visually inspect the charge air cooler, every six months, for dirt and debris that
may be blocking the fins. If the motorhome develops an oil leak, there is a possibility
that the oil will coat the fins of the CAC. Dust will adhere to the oil film and
eventually clog the fins greatly reducing cooling efficiency. When the oil leak is
repaired, the CAC must be thoroughly cleaned.
Rear mounted radiators, with a top mounted CAC, will require more frequent
visual inspections than a side mounted CAC. Litter and dust along the roadway can
restrict the airflow on this type of system. During each oil change
inspect the
engine side of the radiator/CAC assembly for foreign objects that may be
causing restriction.
Spraying degreaser on the charge air cooler, as well as using a steam cleaner, will
not damage the CAC. However, pressure washer and steam cleaner nozzles placed too
close to the CAC can bend the fins. The recommended cleaning procedure for the
CAC, and the radiator, is to use a bucket of mild soap and water. Carefully wash
with a bristle brush then rinse using a garden hose, with minimum water pressure,
standing back a distance to avoid bending the fins.
The Allison MH-2000 series transmission is a fully automatic, torque-converter
driven, electronically controlled transmission. The electronic controls provide
automatic gear selection in all drive ranges and automatic engagement of the
torque converter lockup clutch.
The electronic control system has five major components: the Transmission
Control Module (TCM), engine throttle position sensor, three speed sensors,
Neutral Start Back Up (NSBU) switch and the control valve module. The TCM
processes information received from the throttle position sensor, speed sensor,
NSBU switch and control valve module. The electronic control system optimizes
shift quality by using “Adaptive Shifting.” A wide variety in shifting under varied
conditions is required before optimizing the shift quality. Generally, five typical
shifts of a shift type are needed for shift calibration.
TRANSMISSION