Challenger MT755E Workshop Service Manual

1.10 Selective catalytic reduction (SCR) System
These general instructions need to be followed:
• The selective catalytic reduction (SCR) system must not be contaminated by diesel fuel, oil, or other
hydrocarbons. Damage to the system will result.
If any part of the system has been in touch with such substances, the part must be cleaned very
carefully. If you cannot be sure the part is clean from diesel, it must be replaced.
IMPORTANT: The selective catalytic reduction (SCR) system tolerates only small amounts of impurities.
If there is doubt the diesel exhaust fluid (DEF) tank has been contaminated with diesel fuel, the engine
must not be started before emptying and cleaning the diesel exhaust fluid (DEF) tank, supply module
(including new main filter), dosing module and the diesel exhaust fluid (DEF) lines. See the engine
operator/service manual.
• Do not use high pressure water to wash the selective catalytic reduction (SCR) components.
• As the diesel exhaust fluid (DEF) deposits may cause corrosion, rinse deposits o with low pressure
water.
• Always pay attention to cleanliness. Do not unnecessarily open the hydraulic or electrical connectors, in
order to avoid dirt and diesel exhaust fluid (DEF) entering connectors.
• Using the compressed air for diesel exhaust fluid (DEF) lines, cleaning is not allowed, unless air is oil
free. Oil can damage the system.
• After the engine shutdown, the remaining diesel exhaust fluid (DEF) in system is automatically emptied
back to the diesel exhaust fluid (DEF) tank. During the emptying process, continuous power supply
must be provided for EEM4 electronic control unit (ECU). Pump performing after run is powered
through the EEM4 electronic control unit (ECU), and will run without the key on or battery disconnect
switch on.
WARNING: Diesel exhaust fluid (DEF) is pressurized when the system is in operation. Allow pressure
decrease in the system before any maintenance actions.
1.10.1 Supply module
WARNING: DEF is pressurized when system is in operation. Let pressure decrease in the system
before any maintenance actions.
IMPORTANT: SCR system tolerates only small amount of impurities. If there is doubt that the DEF
tank has been contaminated with diesel fuel, engine must not be started before emptying and
cleaning DEF tank, supply module (including new main filter), dosing module and DEF lines. See
Engine Operator/Service manual.
NOTE: Replace the supply module filter at 1200 hours or annually, unless the DEF tank has been
contaminated. The location of the supply module, is in the front of the machine by the batteries.
1. Access to the filter (1) is below the supply
module.
2. Remove the cable tie (2) holding the DEF
lines to the bracket.
3. Remove the four bolts (3) holding the bracket
to the front casting.
GUID-7C464297-0F5D-4A2A-AEAC-E2F129B3D7A4-high.jpg [High]
Fig. 40
GUID-93890D3C-C199-45A9-AA14-454D326DE326 [V2]
GUID-76C91B11-C2F8-48AC-A5C7-2AE7EFE095D1 [V1]
1. General
1-40 Rubber Track Tractor
79036614D

Challenger MT755E Specifications

General

Brand	Challenger
Model	MT755E
Category	Tractor
Language	English