The Cat® 988 wheel loader from Caterpillar has worked in
global quarry, mining, industrial and construction applications
since 1963, and the present 988H field population numbers
nearly 4,000 units. Included in that tally are 600-plus machines
with more than 20,000 hours, and more than 150 machines
exceeding 30,000 hours — proof of the 988H’s strength in
Building on this 988 legacy, Caterpillar has now introduced an
updated 988H, which blends the best of its predecessor’s
qualities with up to 10% greater fuel-efficiency and new features
that boost production, lower costs, enhance the operator’s
environment and further advance the 988’s legendary durability
and reliability. The refined design of the latest 988H, combined
with the strength of the Cat dealer network, provides
uncommon value for the customer.
Included in the updated 988H package is the new positive flow
control (PFC) implement hydraulic system, designed to boost
loading performance and save fuel. Complementing the PFC
system are redesigned buckets, which load easier and increase fill
factors, plus loader-linkage changes that add breakout power.
Modifications in the braking system improve retarding
capabilities and extend brake life, while new fuel-management
features increase fuel-saving potential. To further refine loading
efficiency, the optional payload control system has increased
accuracy, is more robust in design and easier to calibrate.
For the operator’s comfort, convenience and safety, cab
sound levels are significantly reduced and a new electrohydraulic
implement pod reduces operator effort and fatigue.
Hinged mirrors allow safer access for windshield cleaning, and an
optional heated seat and new radio options (Bluetooth, auxiliary,
MP3 and satellite) mean greater operator comfort.
LOADING POWER AND FUEL-EFFICIENCY
The PFC hydraulic system uses a new electronically managed,
variable-displacement pump that works with an integrated
solenoid valve with force feedback to precisely manage oil flow.
The PFC system assures that pump displacement is always
precisely matched to loading conditions. The system regulates
oil flow in proportion to lever stroke, improving hydraulic
response and creating an overall hydraulic efficiency that results
in less heat and decreased fuel use.
A 5,000-psi (34 500-kPa) pressure boost in the boom-lift
circuit increases bucket-breakout force, and a regeneration valve
on the linkage assures positive cylinder response. The 988H
update also offers a new ‘Performance Series’ bucket line that
retains material more effectively and provides increased fill
factors (volume loaded, versus rated capacity). The buckets have
a wider throat, longer floor and improved setback angle.
The 988H update highlights three programmable fuel-saving
features: the fuel management system (FMS); auto idle kickdown
(AIK); and idle shutdown.
The FMS, which has been standard on the 988H since June
2007, allows customers to set machine parameters to match
production demands. This is accomplished through three modes
of operation— full power mode (FMS not engaged), balanced
mode and maximum fuel saving mode. By choosing either the
balanced or maximum fuel saving mode, the operator can set the
machine to automatically reduce engine speed and hydraulic flow
when the 988H is outside its dig segment, adding to potential
fuel savings by up to 15%.
New for the 988H update is the AIK feature. If the 988H is
not being actively operated for a period of time, the AIK system
will temporarily reduce engine speed to save fuel. The system
automatically resumes engine speed to the previous setting
when the operator engages the implement control pod or the
F-N-R switch or the STIC Steer. The idle shutdown feature, also
new for the 988H update, automatically shuts down the engine
after the machine has been in a safe idling state for an extended
time. The operator receives an in-cab audible/visual warning
before the engine shuts down.
The optional payload control system (PCS) 3.0 is a new onthe-
go weighing system that helps the 988H operator fill each
truck with an accurate payload — typically to within ±1%. The
new system requires calibration only once per year and provides
a simpler interface and an intuitive graphic display. PCS 3.0 can
record details — material, date, time, number of passes and
ticket number — for up to 1,000 truckloads and can identify up
to 50 trucks.
SAFETY AND OPERATOR AMENITIES
In the cab of the new 988H, laminated glass is used in the rear
window and both rear side windows. The laminated windows
have two panes of glass separated by an air gap, which dampens
window vibration caused by external noise sources, such as the
engine and hydraulic pumps. The new windows complement a
laminated windshield and laminated front side windows to
reduce interior sound levels by a significant 1 dB(A), to 72
Loader controls for the 988H update are positioned in a new,
low-effort, electro-hydraulic implement pod that features
fingertip levers that improve both control and ergonomics for
the operator. The new control levers also use ‘soft detents’,
which replace conventional detent magnets with electronic
sensors that provide easier lever control.
New operator-environment features build on traditional 988
safety features, including superior visibility (large glass areas,
long-life LED lights, and optional rear-view camera); access and
egress precautions (lighted primary/secondary stairwells, fullperimeter
railings); maintenance provisions (groundlevel/
platform access, electrical-disconnect switch); and operator
comfort and well-being (adjustable controls, air conditioning,
optional ride-control, secondary steering system).
The 988H update retains all the solid characteristics that have
established the 988’s reputation for durable, reliable, efficient
performance. The new machine’s massive box-section rear
frame and box-shaped loader tower are designed to resist
operating forces, and both use castings in critical areas of high
stress. The distinctive fabricated box-boom has more torsional
stiffness than boom arms used in conventional Z-bar linkages,
and the boom works smoothly with dual bucket links to provide
superior breakout forces and durable performance.
The power train likewise incorporates established 988H
technology, including the Cat ACERT™ C18 engine with
electronically controlled fuel injection and next generation
modular radiator with 14 parallel-flow circuits for optimum
cooling. The field-proven power shift transmission uses the Cat
impeller clutch torque converter and rimpull control system to
balance hydraulic power with tractive
effort, and massive Cat built axles feature
planetary-reduction final drives positioned
at the wheel ends to reduce axle-shaft
As proof of its outstanding ability to
assure customer value, the newest 988H,
as with its long line of predecessor
models, has the design integrity to yield a
life of productive service, then can be
economically rebuilt to yield exceptionally
low lifetime operating costs.
Caterpillar has been operating for over
80 years. In partnership with its
worldwide dealer network, it is driving
positive and sustainable change on every
continent. With 2009 sales and revenues
of $32.396 billion, Caterpillar is a major
presence and a leading manufacturer of
construction and mining equipment, diesel
and natural gas engines and industrial gas