PDF Operation & Maintenance Manual Liebherr A 974 B Litronic Wheeled Excavator - 2 MB
Master the operation and care of your Liebherr A 974 B Litronic Wheeled Excavator with this official manual.
It covers everything from daily safety checks and controls to scheduled maintenance tasks and fluid specifications.
This guide is indispensable for operators and maintenance staff to ensure the machine is used efficiently and kept in excellent condition.
Proper maintenance is key to the longevity of this powerful excavator.
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--- Page 1 ---
Operation and
Maintenance Manual
Litronic
--- Page 3 ---
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GENERAL SAFETY INFORMATION Turn the engine off and remove the ignition key.
Study the Operation and Maintenance Manual Before working on the hydraulic circuit, move all
before operating or working on the excavator. joysticks and pedals with the ignition key in contact
Make sure that you have additional information for position and the safety lever tilted down to relieve the
special attachments of your machine, read it and servo pressure and the remaining pressures in the
understand it! different main circuits. In addition, relieve the
Allow only authorized personnel informed about pressure in the hydraulic tank as described in the
the safety rules to operate, service or repair the Operation and Maintenance Manual.
excavator. Make sure to observe any minimum Secure all loose parts on the excavator.
applicable age requirement.
Never operate the excavator without a complete walk
Allow only properly trained personnel to operate or around inspection. Check if all warning decals are on
work on the excavator, make sure to clearly specify the machine and if they are all legible.
the person who is responsible for set up,
maintenance and repairs. Observe all danger and safety guidelines.
Make sure the operator knows his responsibility For certain special applications, the excavator must
regarding the observance of traffic regulations and be equipped with specific safety equipment. Use the
permit him to refuse any unsafe instructions given excavator only, if they are installed and functioning
by a third person. properly.
Any persons still in training should only operate or Never perform any changes, additions or
work on the machine under the supervision and modifications on the machine, which could influence
guidance of an experienced person. the safety, without obtaining the written permission
from the manufacturer. This also applies to the
Check and observe any person working or installation and adjustment of safety devices and
operating the excavator periodically and regularly, safety valves as well as to any welding on load
if they observe safety instructions and guidelines carrying parts.
given in the Operation and Maintenance Manual. It is forbidden to repair the cab.
Wear proper work clothing when operating or
working on the excavator. Rings, watches, Do not install any equipment or attachments made by
bracelets and loose clothing such as ties, scarves, other manufacturers or any which are not specifically
unbuttoned or unzipped shirts and jackets are authorized by LIEBHERR for installation without first
dangerous and could cause injury! obtaining the written permission from LIEBHERR.
Wear proper safety equipment, such as safety LIEBHERR will issue any required technical
glasses, safety shoes, hard hats, work gloves, documentation for approved installations.
reflector vests and ear protection. Should the electrical circuit be modified or additional
Consult your employer or supervisor for specific components be installed, so the modification must be
safety equipment requirements and safety performed according to the national standards and
regulations on the job site. safety regulations (such as OSHA per the USA).
The installation must be certificated by an approved
Always tilt up the safety lever before leaving the organization and a copy of the certification has to be
sent to the LIEBHERR company.
Do not carry tools, replacement parts or other
supplies while climbing on or off the excavator.
Never use the steering column, control levers or
joysticks as handholds.
Never jump off the excavator, climb on and off the
excavator using only the steps, rails and handles
provided.
When climbing on or off the excavator, use both
hands for support and face the machine.
If needed, use the front window as an escape
hatch.
If no other guidelines are given, perform
maintenance and repairs utilizing the following
precautions :
Park excavator on firm and level ground. Rest
the attachment on the ground.
Place all control in neutral position and raise
the safety lever.
2.2
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CONTROLS AND INSTRUMENTATION IN THE CAB
1 Safety lever- Servo control S71 Switch / Diesel engine RPM control in "manu"
6 Service brake S72 Engine RPM adjustment in mode "manu"
8 Air conditioner vent S73 Switch / Safety mode of the servo circuits
9 Special attachment control * U21 Left joystick
15 Control units - additional attachments * (See U22 Right joystick
page 3.26) U24 Pedal for travel
A3 Radio * U25 Control lever - outriggers
H1 Monitoring display U26 Swing brake (Positioning brake) *
H10-1 Buzzer in left console U38 Control unit - air conditioner
H10-2 Buzzer in right console U45 Joystick for cab position adjustment *
P5 Hour meter U58 Joystick for steering *
S1 Ignition key
S2 Switching unit
S4 Switch / horn * Optional equipment
3.2
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Main screen view
SY field: The upper field of the monitor shows warning and indicator symbols, up to maximum 4 symbols at
the same time.
If more than 4 symbols must be shown, then every 10 seconds, the symbols move to the left by one
symbol.
The following list shows all symbols which can appear in this field
The EC window displays any applicable error codes for any electrical errors in the excavator
EC field:
electronics, (line errors, sensor errors, ...). Max. 7 error codes can be displayed at the same time . If
more than 7 errors occur, an arrow next to the error code window points to additional error codes on
the list.
Press the arrow key to move the error code window in the selected direction on the error code list.
For detailed error codes list, refer next
INF field: The INF field on the right hand side of the main
screen displays temporary information, also in graphic
form.
If more than 3 symbols must be shown, then every 10
seconds, the symbols move to the left by one symbol.
Displays are shown as graphics or text and inform
about specific operating conditions (such as actuated
flow reduction, emergency operation of Diesel engine
TI field This field, at the bottom right of the screen displays
the main hour meter and the daily hour meter of the
machine.
During the display start-up phase, the operator will be
alerted about a possible upcoming service interval, by
a graphic symbol. In this case the hours of this interval
are displayed instead of the machine hour meter (as
an example 500 hours on fig. beside).
The recalling of upcoming service interval lights up to
about 8 seconds.
The symbol is displayed when a flow limitation is
activated for the pumps.
The symbol indicates that no flow limitation for
the pumps is actually activated.
Control of the screen at error recognition:
In case a new error, displayed in field SY, is recognized, the presentation will return to main screen, and the
corresponding symbol is displayed.
Depending on the default (urgency step), the buzzer will alert acoustically at the same time, either buzzing in
continuous or emitting intermittent sounds.
The symbol signals that the buzzer of the control unit is activated. Using the key it is possible to quit
the defaults indicated by a continuous buzzing.
3.12
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MENU ("set option")
ALLOCATION OF FLOW LIMIT OPTIONS TO THE EXTERNAL INPUT I1
(Special attachment input; as an example for operation of hydraulic hammer,
In this menu, pre-defined flow limitations (options) are allocated to the
hardware input I1.
The arrow near the symbol gives the actual allocation. (fig. 24).
In example fig. 24, the option 3 is active for the input I1. This means, if the
fig. 24 external hardware input I1 is activated, then the nominal pump values
allocated in option 3 for the excavator control are given as maximum
nominal values.
If another option must be allocated to input I1 (as an example due to a
replacement of the working tool), so first select another attachment in the
vertical symbol range via the key "UP" or "DOWN" (as an example in fig. 25,
the option 10).
Confirm the selected option by pressing the "MENU" key, the new option
must then appear in the column.
The right part of the screen provides indication for the currently set pump
values corresponding to the option shown in the selection window.
fig. 25
The values EV1 up to EV3 determine the flow limitation of the main pumps
when the special attachment is actuated.
Notice: - The pump choice EV2 does not appear for the Load
Sensing machines R 904 up to R 924.
- The pump choice EV3 only appears on machines fitted with
three independent adjustable working pumps (R984, Special
machines, ...).
The value EV6 determines the maximum allowed pressure level for the
actuation of the special attachment.
The value behind the choice "Quota" is without importance for crawler
excavators.
When selecting an option, a designation related to this option is displayed in
the right lower area of the screen, provided that this designation has been
memorized during the setting of the parameters of the option.
As an example, in fig. 24 the designation "HM2000" appears, which is the
designation for the hydraulic hammer allocated to the selected option.
MENU ("set service")
INFORMATION AND CONFIRMATION OF SERVICE INTERVAL
This screen is an information screen and can be used to confirm a
completed service interval.
The screen shows the operating hour for the next service interval (in
example beside ="500 hrs") and the current operating hours ("174 hrs").
fig. 26
3. 22
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Control unit S232 - Standstill cab heater
This unit controls an eventually installed standstill heater for the cab or .other circuits on the
uppercarriage. Refer to the special issued operation and maintenance manual of the maker of the
additional heater.
Key switch S247 - Commutation Normalized control system / Special control system
This key switch allows to commute electrically from a Standard lever arrangement (ISO - PCSA) into a
Special lever arrangement (LIEBHERR, other lever arrangement, ...).
Touch S275 - Additional floodlight on rear of cab roof
Actuating the touch will turn on and off above mentioned floodlight. At the same time, the control light
inside the button will light up and go out.
Touch S276 - Additional floodlight on counterweight
Same control as for S275.
Touch S321 - Joystick Steering
On machines for which the wheels are steered via a two ways control lever (Joystick U58, see page
3.4) the electrical control circuit for the steering is made alive via the touch S321 (indicator light in the
touch is on ).
On machines fitted with an adjustable operator's cab with 2-stage elevation, the joystick U45 (see page
3.4) for the control of the cab movements is made alive via the touch S370. The cab adjustment
movements via U 45 are possible only as long as the touch S370 is held depressed.
3. 32
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Fig. 19
Note:
Data transmission from the operating feature to the control unit is faulty, cause of the
fault, short-circuit or interruption of the data line to control unit, plug connection on
operating feature or control unit.
The operating feature continues to try to establish data connection to the control unit, if
Faulty data transmission is displayed flashing!
Note:
If the data transmission from the operating feature can not be established again, the ignition must be switched off, and RESET will be
carried out following the restart!
3.42
--- Page 11 ---
HYDRAULIC PUMPS SAFETY OPERATION
. During normal operation of the excavator, the electronic
horsepower control continuously adjusts the pumps flow to
the pressure level of the working circuits.
. If a trouble occurs in the circuit of the regulator, the pumps
are swivelled back to minimal flow.
. However, it remains possible in this case to carry on the
working with the machine (with somewhat reduced pump
power) by changing over the lever 3 on the servo oil unit
which is mounted to the rear face of the spool valve
29 console.
. Disconnect the connector 1 from the solenoid valve, pull
out the pin 2 and tilt the lever 3 in horizontal position (safety
position).
4.8
--- Page 12 ---
ATTACHMENT CONTROL
. When working, always position the excavator on the
outriggers (fig. 69).
. Your excavator is designed to operate in one fixed position,
i.e. for all the movements of the uppercarriage and of the
working attachment (loosening, picking up, displacing
the outriggers.
69 CAUTION
Before starting operation, always immobilize the excavator
on the outriggers.
Do not operate the attachment as long as the excavator is
not stabilized on the four outriggers.
Check and make sure no personnel is within the area of
operation of the outriggers during their movements.
zone to leave immediately.
The lift capacities chart is given for the excavator
immobilized on the outriggers.
For work application :
apply the service brake while fully depressing the
brake pedal 6 until the retainer latch 1 engages,
70 release the parking brake (the control light in the
button S16 may not be on, otherwise the buzzer will
sound for warning),
The selector switch S55 for forward / reverse travel
must be in position -0-.
NOTES ON MACHINE-FRIENDLY OPERATION WITH THE
ATTACHMENT
. Never stop the swinging motion of the uppercariage when
lowering the attachment while striking the bucket or the
grab into the material to be loaded or against any obstacle
else
. Inspect the machine for damage if the attachment has been
swung into a wall or any other obstacles.
. Applications in which the attachment is to be used to strike
the material being extracted are not permitted, even when
working in a longitudinal direction.
. Repeated strikes against an object leads to damage to the
steel structures and machine components.
. Please refer to your LIEBHERR dealer if special teeth (or a
special tool) for heavy-duty or special applications are
required.
. Do not lift the machine during operation. Should this
happen, lower the machine slowly back to the ground.
72
4.18
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3) ENGINE COOLANT - Specifications for anticorrosion and antifreeze protection
Using a mixture of antifreeze and anticorrosion with "DCA 4" anticorrosion additive.
To assure the protection from corrosion of the cooling system, the coolant must contain at least
50% corrosion / antifreeze mixture all year round. This protects the cooling system to about - 35°
C ( - 33° F).
When fluid is added to the coolant mixture, it must be assured that the mixture maintains a 50% antifreeze
content.
Caution : The percentage of antifreeze should not exceed 60 % . A higher concentration would lead
to reduced antifreeze and cooling properties.
In addition, the cooling system must contain DCA4 (DCA = Diesel Coolant Additive) from FLEETGUARD. The
prescribed concentration is from 0.3 to 0.8 DCA units per liter of coolant (1.2 to 3.0 units per US Gallon).
The coolant must be changed every 2 years. Before adding new coolant, check the circuit for cleanness and if
necessary flush it with water.
Using a mixture of water and DCA4 (without antifreeze and anticorrosion)
In certain circumstances, and if ambient temperatures are constantly above the freezing point, for instances in
tropical regions, and if there are no corrosion or antifreeze fluids available, then a mixture of water and DCA4
additives may be used.
To maintain sufficient anticorrosion properties however, the DCA4 concentration of the coolant must in this
case be about doubled in comparison with the one prescribed when using a mixture also containing
antifreeze and anticorrosion, it equals a concentration from 0.6 to 1.6 DCA units per liter of coolant (2.4 to 6.0
units per US Gallon) .
Important !
If employing a mixture consisting only of water and DCA4 additives :
the use of coolant refiners (corrosion protective oils) is not authorized,
the coolant change interval must be reduced to once a year.
Checking and maintaining the right DCA4 concentration in the cooling circuit
To check the DCA4 concentration, we recommend the use of the test kit CC 2602 M from FLEETGUARD
(LIEBHERR order No 5608459).
The water filter mounted in the cooling circuit contains from 4 up to 8 DCA4 units, see the following schedule.
When changing the filter, the corresponding units are added to the cooling circuit.
If there are no significant coolant leakages, regularly replacing the water filter every 500 working hours is
sufficient to maintain the correct concentration of anticorrosive agent.
The DCA concentration has to be checked before each filter change, after each important coolant make up,
and at regular intervals if smaller coolant quantities are refilled frequently.
If the concentration is too low, or when changing the coolant in the system, the remaining necessary DCA4
units must be added to the system in liquid form (see schedule).
The LIEBHERR order number for a 0,5 liter can containing 5 DCA4 units is 7363898..
Cooling system Quantity of DCA4
DCA4-Water Filter (1) For use with a
capacity liquid(1) mixture containing
(liter / US. LIEBHER DCA4 0,5 liter
50% antifreeze and
Gallons) Designation DCA4 units anticorrosion
R order no units cans
24 - 39 / 6.3-10.4 WF 2071 7367045 4 3 15
40 - 59 / 10.5-15.7 WF 2072 7381493 6 4 20
60 - 79 / 15.8-20.9 WF 2073 7367052 8 5 25
80 - 115 / 21.0-30.4 WF 2073 7367052 8 8 40
Fresh water guidelines:
To mix the coolant fluid, only clean, preferably soft water should be used. Often, but not always, regular
drinking water can be used. Sea water, brackish waters, sole water or industrial waste water may not be
used.
5.6
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OIL IN THE HYDRAULIC SYSTEM
. When checking the oil level or adding oil, (fig. 21) :
Park the machine on level ground,
rest the attachments on the ground with stick and tilt
cylinders fully extended and, if applying, with bottom
dump bucket closed.
turn the engine off.
21
CHECK HYDRAULIC OIL LEVEL
. In this position the oil level may not drop below middle level
on the sight gauge (fig. 22) or oil must be added to the tank
until reaching this level.
.
. Level "MAXI" shows the maximum oil level when all
cylinders are retracted.
. Level "MINI" shows the minimum oil level when all cylinders
are all the way extended.
22 TO DRAIN AND TO ADD OIL TO THE HYDRAULIC TANK
CAUTION
Before draining the oil or opening the hydraulic tank,
you always must first unscrew the breather filter 4 one
turn to relieve tank pressure.
. The hydraulic system should always be refilled or drained
using a filler pump
.
. To drain oil:
. Remove the cover of the return filter 1 or the cover 2.
23 . The oil must be drained via the two drain valves 5 and 6 in
the bottom of the tank (fig. 27).
. Attach a drain hose to the valves and suck off or let flow out
the oil.
.
. Adding oil to the tank:
. Unscrew the breather filter 4 one turn.
. Add the oil via the filter cover 1 or via the cover 2, until the
oil level reaches middle level on the sight gauge..
. Close the breather filter.
. Add some more oil to fill the tank up to the top. If refilling
through the opening of the filter cover 1, pay attention to
refill also the return oil compartment R (fig. 26) around the
filter centring tube 7 completely.
. Reinstall the filter cover 1 or the cover 2.
24
5.16
--- Page 17 ---
THE HYDRAULIC SYSTEM
. Maintenance of the hydraulic system is limited to the
hydraulic tank.
. None of the other components in the hydraulic system
require special maintenance..
. However, hydraulic lines and hoses must be regularly
checked for leaks.
. Cleanliness in the hydraulic system is especially important.
. For this reason, the given maintenance intervals to replace
the return filter, to clean the oil cooler, and to change the oil
25 need to be strictly observed.
DANGER
DO NOT ALLOW YOUR SKIN TO COME INTO CONTACT
WITH HOT OIL OR COMPONENTS CONTAINING HOT OIL.
At or near operating temperature, engine and hydraulic oil
is hot and can be under pressure.
. Always relieve the hydraulic pressure before working on the
hydraulic system.
. Apply both joysticks (with ignition key in contact position)
and then unscrew breather filter (fig. 29, pos. 4) one turn to
depressurize the hydraulic tank.
OIL COOLER
. A clean oil cooler is necessary to achieve optimum
hydraulic oil cooling.
. Clean the cooling circuit with air or steam at the intervals
specified in maintenance schedule, and more often if the
working conditions make it necessary
RETURN FILTERS
. The magnetic rod in the return filter (fig. 28, pos. 2) should
be cleaned daily during the first 300 operating hours, then
every week
. Change fibre glass filter element 5 after the first 500 and
1000 operating hours.
. Further changes of this element
. - every 1000 operating hours,
. - and with every occurrence of damage caused by
contamination of the hydraulic system.
. Notice: When working under very dusty conditions
observe the special recommendations
concerning the element change on page 5.9
28
6.10
--- Page 18 ---
THE HEATER AND AIR CONDITIONER
. Heater and air conditioner unit
. Remove and clean the re-circulated air filter 4 and the
fresh air filter 5 of the air conditioner unit every 500
working hours and more often in very dusty conditions.
. If the filters are contaminated, the air flow through the
exchangers is reduced, this causing frequent icing and
stop of the air co plant.
. Blow out the filter elements with pressure air, or clean
them in cold or lukewarm water. Never wash the
65 elements with warm water or using a steam jet. Filter
elements which are damaged or in bad condition must be
replaced at once.
. Never operate the machine, even for a short time when
the filters are removed, this would cause a very quick
clogging of the heat exchangers of the unit.
. To remove the re circulated air filter 4, tilt the backrest of
the driver's seat forward and turn both quick locks (pos.2,
fig. 65) by 90 degrees.
. The fresh air filter 5 is accessible from the outside of the
cab, after removal of the deflector 6 (fig. 66).
. Once a year check for damage the lamellas of the heat
66 exchanger 9 (evaporator and heater unit) and in case of
clogging blow the exchanger out with pressure air .
. If necessary put the lamellas straight.
.
. Heater circuit
. The following maintenance should be performed annually
before the beginning of the cold season:
. - check the heater water circuit for leaks,
. - check and if necessary retighten all connections, hose
clamps and the seals on the water valves,
. The heater should only be used with a DCA4 antifreeze
and anticorrosive mixture. When changing the engine
coolant, close the heater valves on the engine (fig. 67).
67 Otherwise the heater core must be vented correctly after
refilling the circuit.
. To vent the circuit, remove the red cap at bleeder valve
through the opening A (fig.65), press the valve to let the
air escape.
. In addition, annually before the beginning of the cold
season, and at least if insufficient heating is noticed,
remove and clean the solenoid valve Y46 (fig. 68) which
controls the warm water flow.
. Clean the membrane of the solenoid valve with clear
water and check that the compensation orifice at the
membrane is not clogged.
68
6.20
--- Page 23 ---
MAINTENANCE
Maintenance of the cab elevation is limited to the essentials, with regular visual checks of the
structure and the elevation's hydraulic system.
Determined malfunctions are to be remedied immediately.
Additionally, the machine should be washed periodically. Worn seals, cracks and other faults are
difficult to spot on a dirty machine.
All repair work on the elevation is to be carried out while the cab is positioned on flat and even
ground .
Depending on the repair, all the necessary parts are to be supported. Only walk underneath the
parts if they are supported.
Structure of the cab elevation
All bearing points are lubricated via the central lubrication system. Each bearing point should be
checked visually for the exuding of grease every day.
Visually check the condition of the cab elevation daily, and inspect for parts that may have
broken off, fallen off or are worn.
The fixing screws on the base of the cab elevation for the uppercarriage structure should be
checked for secure fastening every 500 operating hours and retightened.
The tightening torque of these M30 fixing screws is 2300 Nm.
Modifications such as drilling, burning or welding on components that serve as a power
transmission to the elevation may only be carried out by the manufacturer or by an authorised
contracted workshop .
Never stick your fingers into the bolt boreholes when replacing bolts or when carrying out other
tasks. Use a suitable pin to straighten the boreholes.
Hydraulic system for the cab elevation
Before working with the machine, a visual check of seals for the cab elevation's hydraulic system
must be carried out daily.
Modifications to the adjustment of the elevation's hydraulic components may only be carried out
by the manufacturer or by an authorised contracted workshop.
Before each intervention in the hydraulic circuit, the control pressure and the dynamic pressures
in the elevation's working circuit are to be released as follows....
bring the start key into the contact position (safety lever must be in the down position),
switch on the servo-control circuit for cab adjustment while depressing the push button S370.
briefly actuate the joystick U45 in all 4 directions (keep S370 pressed down).
Release of pressure is resulted despite the pipe-break protection valves installed on the
hydraulic cylinders of the cab elevation .
then release the push button S370 and start key
....and release the tank's internal pressure as described before in this operation and maintenance
manual .
Every 1000 operating hours:
thoroughly wash the entire machine,
then visually inspect the hydraulic hoses and hydraulic components for leaks, damage or
other faults.
visually inspect the steel structure parts for crack formations.
8.1.14