Automatic Transmission - PREVOST Motorcoach XL Series Operator's Manual

1. Tag axle unloaded or retractable
Vehicle can be fitted with either the standard tag
axle unloaded system or the optional retractable
tag axle system. When valve is switched to the
"Wheels up" position, the tag axle air springs are
unloaded (depleted) with the tag axle unloaded
system or, tag axle is raised with the retractable
tag axle system. For both systems' descriptions,
see page 4-21.
2. Parking brake control
See "Combination
brakes" on page 2-28.
3. Door override
In the event of a malfunction in the front entrance
door air lock mechanism, press this button to
release air lock (see page 3-4).
4. Parking brake override (Optional) or
Low-Buoy (Optional)
Parking brake override:
operation, primary system air pressure drops
below 40 psi (276 kPa), spring-loaded parking
brakes will automatically be applied at full capacity
on drive axle to stop vehicle. Cause of pressure
loss should be determined and corrected before
proceeding. However, vehicle may also be
equipped with an optional parking brake release
system (Parking brake override) which will allow
driving the vehicle for a short period of time to a
safe parking area. To operate, push and hold
down the control knob with vehicle in motion.
Low-Buoy: Low-buoy option is used to lower the
coach by approximately 4 inches (100 mm) when
valve is positioned towards "LOW-BUOY". For
system description, see page 3-3.
5. Auxiliary Preheating System Timer (Optional)
(WEBASTO (shown) OR ESPAR)
See pages 2-46 & 2-47 for description of both
heaters.
emergency and parking
If during normal
5A. Preheater switch
Push down rocker switch to turn "ON" Preheating
system; supplementing Central Heating System
when required.
"OFF" automatically
temperature.
6. Transmission push-button shifter
Use shifter to select forward, neutral or reverse
gears of transmission.
TRANSMISSION"
described hereafter.

AUTOMATIC TRANSMISSION

The operation and driving of this vehicle with an
automatic transmission is similar to that of an
automobile equipped
transmission. Proper ranges should be selected
according to driving speeds to improve vehicle
performance and control.
fully automatic. Speed ratio of power converter
changes automatically as vehicle speed increases
and direct-drive goes in and out as necessary,
modulated by vehicle speed, and accelerator
position.
Range selection - Push-button shifter
The push-button shifter is used by the operator to
select Neutral (N), Reverse gear (R), or a range of
forward gears. When a forward gear range has
been selected, the transmission starts in the
lowest gear of the range and, as conditions
permit, automatically upshifts until the highest
gear in the selected range is in use.
FIGURE 26
The digital display indicates the readout of two (2)
digits:
2 - 23
CONTROLS/INSTRUMENTS
Preheater will turn "ON" and
depending on
"AUTOMATIC
system operations
with an automatic
The transmission is
coolant
are
18015