PREVOST X3-45 COMMUTER User Manual

SECTION 12: BRAKE AND AIR SYSTEM
DOB 1300-1556 | X3-45 Commuter PA-1648 Maintenance Manual First release Oct 2020
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1 – cartridge canister
2 – air dryer base
2.1 – safety valve
2.2 – outlet check valve
2.3 – turbo-protection valve TPV
2.4 –heater element
3 – valve unit
Haldex Gemini MDx Overview
In its most basic form, the Gemini MDx dual
dryer is the connection of two DRYest Air Dryers
in parallel to treat the compressed air produced
by high capacity air compressors. The
GeminiMDx is a desiccant type dryer that
removes moisture and contaminants from the
compressed air before entering the air brake
system.
Dual Consep (Condenser/Separator) pre-treats
the compressed air before entering the air dryers
and extend the life of the air dryer’s desiccant
cartridge.
The electric air dryer is controlled by the
multiplex system. If the air dryer should for some
reason become powerless, it will cease to
function and the desiccant will become wet
through, while the compressor will continue to
charge. Relief is provided via the safety valve.
By using the information from the vehicle
electronic system, the air dryer and compressor
control is optimized, so that drying of the air is
guaranteed and fuel consumption is reduced.
This will be noticed as a different compressor
start/stop pattern.
The air dryer is located in a small compartment,
aft of the evaporator compartment.
FIGURE 15: AIR DRYER LOCATION – STREET SIDE
For more information on Haldex Gemini MDX
Twin Air dryer, refer to the following manual
included on your Technical Publications USB
flash drive:

PREVOST X3-45 COMMUTER Specifications

General

Engine	Volvo D13
Transmission	Allison B500
Fuel Type	Diesel
Length	45 ft (13.7 m)
Width	102 in (2.6 m)
Horsepower	500 hp
GVWR	54, 000 lbs
Height	141 in