Hydraulic Brakes; Transmission Breather - Blue Bird TC/2000 Owner's Manual

erate the engine to 1200-1500 RPM. This should reduce the sump temperature to operating level within two
or three minutes. If high temperature persists, stop the engine and have the overheating condition investi-
gated by service personnel.
If excessive temperature is indicated by the transmission oil temperature gauge, check the oil level in
transmission. (Refer to the Oil Check Procedure in your Allison Transmission operators manual). Stop the
vehicle and shift to neutral. Accelerate the engine to 1200-1500 RPM. The temperature should return to
normal within two or three minutes before the vehicle resumes operation. Normal temperature for both on
and off-highway operation is 160-200 degrees F. Oil temperature should never exceed 250 degrees F. In units
equipped with the MD 3060 transmission, if the sump oil temperature reaches 250 degrees F, the ECU will
inhibit operation in the higher gears and turn on the "OIL TEMP" light which is located on the shifter cover.
If high temperature in either engine or transmission persists, stop the engine and have the overheating
conditions investigated by maintenance personnel.
CAUTION: The engine should never be operated for more than 30 seconds at full throttle with the trans-
mission in gear and the vehicle not moving. Prolonged operation of this type will cause the transmission
oil temperature to become excessively high and will result in severe overheat damage to the transmission.
If the transmission overheats during normal operation, check the oil level in the transmission.

TRANSMISSION BREATHER

The transmission has a self-contained breather near the cooler line ports. Care should be exercised to
avoid plugging this breather with paint, undercoating or any other material. The breather provides a passage
for normal expansion and contraction of air and fluid within the transmission. A small amount of oil mist
comes out of the breather during normal operation. If an excessive amount of oil is found in this area, the
cause should be investigated.

HYDRAULIC BRAKES

Bendix hydraulic disc brakes are standard on all body models.
The hydraulic brakes have the Bendix Maxi Power Booster dual hydraulic brake system. The system has
a two-compartment reservoir mounted on the floor behind the driver. The Hydro-Max Booster is a hydraulic
assist system using a hydraulic power steering pump. The hydraulic power steering pump is gear driven by
the engine. There is an electrical back up power assist in the event of a malfunction in the hydraulic power
pump system or loss of engine power. The battery provides the reserve power for the electrical back up
power assist.
CAUTION: Hydraulic Brake Systems are power assisted. Braking capacity is reduced without engine
assist. Do not move bus with dead engine.
The electric power back up pump will operate whenever the engine is not operating and the key switch is
in either the ON or START position or when the key is in the OFF position and the brake pedal is depressed.
Test daily by feeling for the electric motor operation while applying the brakes with engine not operating,
or when the key switch is in the ON or START positions and the engine is not operating. The pedal will
initially be hard to push, and then the pedal will be softer to push as the electric motor starts.
WARNING: Do not drive the bus when the electrical back up pump does not operate. In the case of a loss
of a power assist, there will be reduced brake capacity without the electrical backup.
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