Water In Fuel Sensing System (Optional); Deutz Turbocharger Operation; Operating Practices - JLG 1850SJ Service And Maintenance Manual

SECTION 3 - CHASSIS & TURNTABLE

3.18 WATER IN FUEL SENSING SYSTEM (OPTIONAL)

The Water in Fuel Sensing System detects when there is an
excessive amount of water in the fuel and sets a DTC code in
the JLG Control System to alert the operator and/or service
technician.
When a Water in Fuel condition occurs, the machine will
respond in the following way:
• The engine will shut down automatically.
• The JLG Control System will set DTC 4375 - Water in Fuel
• An alarm will sound from the active control station (ground
or platform)
• If in platform mode, the Low Fuel Indicator will flash
Engine Restart will be permitted after the machine senses the
Water in Fuel condition, but will only run for 2 minutes and the
engine will shut down again. This restart process will continue
until the Water in Fuel condition is corrected.

3.19 DEUTZ TURBOCHARGER OPERATION

Good engine operating procedures are essential to prolong
turbocharger life.
Particular attention to oil system and air system will eliminate
the two main causes of turbocharger failure. To prevent this
Operators/Owners must ensure that :-
1. Air and oil filters are checked regularly to the manufac-
turer's specifications.
2. Engine maintenance intervals are adhered to.
3. Engine and equipment are operated in such a way that
is not harmful to the life of the turbocharger.

Operating Practices

Operators and owners can get maximum service life from their
turbochargers if a few good practices are followed:
START UP
When starting the engine use minimum throttle and run in
idle mode for approximately one minute. Full working oil pres-
sure builds up within seconds but it is useful to allow the tur-
bocharger moving parts to warm up under good lubricating
conditions. Revving the engine within the first few seconds of
start up causes the turbocharger to rotate at high speeds with
marginal lubrication which can lead to early failure of the tur-
bocharger.
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AFTER SERVICING
After servicing the engine or turbocharger, ensure the turbo-
charger is pre-lubed by adding clean engine oil into the turbo-
charger oil inlet until full. After pre-lubing, crank the engine
without firing (engine/fuel pump stop out) to allow oil to cir-
culate through the full system under pressure. On starting the
engine, run at idle for a few minutes to ensure the oil and bear-
ing systems are operating satisfactorily.
LOW AIR TEMPERATURES & INACTIVE OPERATION
If the engine has been inactive for some time or the air tem-
perature is very low, crank the engine first and then run at idle.
This allows the oil to circulate throughout the full system
before high loads and speeds are applied to engine and turbo-
charger.
SHUT DOWN
Before shutting the engine down, let the turbocharger cool
down. When an engine runs at maximum power/high torque,
the turbocharger is operating at very high temperatures and
speeds. Hot shut down can cause reduced service life which is
avoidable by a minute or two of idling. Most mobile equip-
ment applications include an adequate cooling period during
parking or mooring procedures.
Allow the engine to idle for 1-5 minutes to allow the high tem-
peratures and speed to reduce and thus prolong the life of the
turbocharger.
ENGINE IDLE
Avoid running the engine for long periods in idle mode
(greater than 20-30 minutes). Under idling conditions low
pressures are generated in the turbocharger which can cause
oil mist to leak past seals into the two end housings. Although
no real harm is done to the turbocharger, as load is applied
temperatures increase and the oil will start to burn off and
cause blue smoke emission problems.
In the picture above you can see discoloration on the shaft
caused only by heat. If the engine is allowed to Idle for a
period of time, lube oil will continue to flow cooling the tur-
bine shaft.
You can also see spots on the turbo where grooves have been
"worn" in to the turbine shaft at the point where the radial
bearing sits. Dirty oil/contaminates in the oil can become
trapped in between the radial bearing and the surface of the
shaft becoming abrasive and ultimately grinding away the
material.
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