Milton CAT 988H User Manual

Engine

Engine Model Cat®C18 ACERT

®

Gross Power 414 kW 555 hp
Flywheel Power 373 kW 501 hp

Operating Specifications

Operating Weight 49 546 kg 109,249 lb
Rated Payload 11.4 tonnes 12.5 tons

Buckets

Bucket Capacities 6.3 m3–7.0 m

3

8.2 yd3–9.2 yd

3

988H

Wheel Loader

®

®

2

988H Wheel Loader

Improved performance and rugged durability combine with operator comfort
for maximum productivity.

Revolutionary design, Caterpillar

®

quality.
Electro-hydraulic controls, increased power
and torque rise, front linkage and unmatched
operator comfort work together for increased
performance and added durability to make
the 988H an innovative, 21st Century large
wheel loader geared for maximum production
in the toughest conditions.

Maintenance and Serviceability

Most daily maintenance checks are
performed from the machine’s left side,
facilitating quick start up. Case drain
filters for main hydraulic, steering and
fan pumps protect against contamination,
and remote pressure taps contribute to
improved serviceability. Easy access to
major components enhance serviceability
and increase uptime. pg. 15

Application Truck Match

Increased performance and good pass
matching make the 988H a versatile
performer. pg. 14

Hydraulics and Electronic Monitoring

Innovative electro-hydraulics play a
key role in performance of the 988H
and provide lower operator effort.
Increased hydraulic efficiency improves
lift and tilt cycle time for reduced overall
cycle time. The tradition of reliable,
high-performance Cat hydraulics
continues. pg. 8

Power Train

The Cat C18 engine with ACERT

®

Technology is U.S. EPA Tier 3/EU
Stage III compliant. The Cat transmission
and impeller clutch torque converter
offer smooth, consistent shifting with
fingertip control. Electronic controls
help increase productivity. pg. 6

✔

Structures and Fabricated Box Boom

The articulated frame design features a
high-torsion, compact, load-absorbing,
front frame and a large, box-section,
engine-end frame. Fabricated boom
and linkage geometry increase dump
clearance, provide improved breakout
and lift forces and increase the viewing
area to the bucket corners. pg. 4

✔ New Feature

3

Customer Support

Your Cat dealer offers a wide range of

services that help you operate longer

with lower costs. pg. 16

Bucket Match

Improve machine performance and
increase stability by selecting the right
bucket for your application and material
density. pg. 13

Buckets and Ground Engaging Tools

(GET)

Choose between 6.3 m3(8.2 yd3) and

7.0 m3(9.2 yd3) capacity buckets, spade

edge and straight edge buckets and

various GET to match job conditions.

Cat buckets retain the proven shell-tine

construction design for unmatched

durability. pg. 12

Operator Station

Experience a high level of efficiency,
comfort and productivity with one-hand
STIC operation, a large cab, low-effort
fingertip lift and tilt controls, improved
operator visibility, reduced sound levels,
improved ventilation and easier entry
and exit. pg. 10

Structures. Combine the use of robotic
welding and castings in critical high­stress areas. More than 90 percent of
the 988H structure is robotically welded
to provide highly consistent welds and
increased strength. Castings are also
used in several areas to increase strength
by helping to spread the loads and reduce
the number of parts.

1 Full Box-Section Frame. Has been
improved for maximum strength and
minimum weight. The frame rail is now
extended further forward, improving
rail to hitch strength.

2 Box-Shaped Tower. Is designed
for improved resistance to twisting
for maximum strength. The tilt cylinder
tower’s high-strength steel plates direct
stress down to the lift cylinder case
mounting tube, absorbing impact and
loading forces. This design results in
a narrower tower which gives a better
operator viewing area.

4

Superior design of structures, along with the bold, box-section front linkage
provide superior strength.

Structures and Fabricated Box Boom

3 Upper and Lower Hitch Pins. Pivot on

double-tapered roller bearings. The hitch
plates are shaped to direct stress away
from the end of the weld, resulting in
a smoother transition of stress loads
into the frame.

4 Spread-Hitch Design. Increases the
spread 26 percent to help square-up the
frame and provide increased clearance
for access to the hitch and hydraulic lines.

5 Steering Cylinder Mounts. Are located
on the axle pads to provide efficient
transfer of steering loads to the axle.

6 Fabricated Box Boom. Replaces the
traditional steel plate lift arms found
on wheel loaders. This design features
forked ends for easier service, faster
assembly and increased reliability.
Castings in high stress areas smooth
the transition of stress distribution for
excellent service life. The boom and dual
bucket links work together for increased
breakout force, better torsional resistance
and higher lift capacity.

Fabricated Boom Box-Section Design.

Has more torsional stiffness than a Z-bar

design. With the parallel lift arm design,

corner loading the bucket sends stresses

up the lift arm, through the cross tube

welding and up the other lift arm.

The box-section design spreads stresses

over the full length and perimeter of the

boom, allowing stress transfer through

parent material. This resists twisting

and prevents stress paths that can

lead to cracking.

Weld Joint

Load Path

Load Path

(Full Length)

5

1 Cat C18 Engine with ACERT

®

Technology. Is U.S. EPA Tier 3 and
EU Stage III compliant. It features
increased horsepower and efficient fuel
management for quick response, high
productivity and exceptional service life.
A new, sculptured cylinder block provides
greater strength and lighter weight.

988H Fuel Management System.

The Cat 988H Wheel Loader Fuel
Management System delivers solid
productivity and fuel savings of as much
as 15 percent in truck loading and more
in load in carry operations. By lowering
engine speed during all but the digging
portion of each cycle, the proprietary
system minimizes impact on productivity
while gaining significant fuel savings.
For maximum flexibility, the system
offers three different operating modes:
full power, balanced and maximum fuel
savings. The system allows the operator
to quickly adjust to changing production
demands by moving a single switch
mounted in the cab.

The Fuel Management System can
be retrofitted to 988H Wheel Loaders
already working in the field.

Mechanically Actuated, Electronic Unit
Injection (MEUI). Proven high-pressure,

direct injection fuel system electronically
monitors operator demands and sensor
inputs to optimize engine performance.

Air Cleaners. Are dry-type radial seal
with primary and secondary elements
and precleaner.

ADEM™ IV. Controls the fuel injector
solenoids to monitor fuel injection.
This system provides automatic altitude
compensation, air filter restriction
indication and it will not allow the
engine to fire until it has oil pressure,
acting as cold start protection and
a form of pre-lube.

Air-to-Air Aftercooler (ATAAC).

Provides a separate cooling system for
the intake manifold air. The ATAAC
system routes hot, compressed air from
the turbo and cools it with a single pass,
air-to-air aluminum heat exchanger.
The cooled compressed air greatly reduces
the emissions produced, meeting the
EPA Tier 3/EU Stage III requirements.

2 Separate Engine Cooling System.

Isolates the radiator and fan from the
engine compartment for more efficient
cooling and allows for a sloped hood
for an increased viewing area.

6

The Cat power train delivers top performance and durability in tough applications.
Changes to the aftercooler, injectors, bearings and pistons help improve startability,
response, power, emissions and fuel consumption.

Power Train

1

Next Generation Modular Radiator
(NGMR). Improves cooling capabilities

by using a parallel flow system with
six cores. Serviceability is improved
with NGMR since there is no top
tank to remove.

3 Electronically Controlled Cat
Planetary Power Shift Transmission.

Features perimeter-mounted, large
diameter clutch packs that control inertia
for smooth shifting and increased
component life.

Demand Fan. The Cat C18 electronic
engine continuously gathers information
to control the demand fan speed and
provides constant net horsepower
regardless of operating conditions.
This compensates for varying fan loads
and enables the machine to maintain
normal system temperatures and reduce
fuel consumption.

4 Impeller Clutch Torque Converter

(ICTC). Combined with the Rimpull

Control System (RCS) allows the

operator maximum flexibility in

modulating rimpull.

• Calibration procedure improved.

• Left pedal modulation improved.

• Wear compensated for by providing
the ability to recalibrate for optimum
left pedal modulation regardless of
torque converter wear.

• Left brake pedal modulates rimpull
from 100 to 25 percent for reduced
tire slippage and wear. After 25 percent
is achieved, further pedal travel
applies the brake.

• RCS allows operator to select from
four preset maximum rimpull settings,
other than 100 percent, that are
available in first gear (90, 80,
70 and 60 percent).

• A lock-up clutch torque converter
provides direct drive efficiency.
Translates into improved fuel
efficiency in certain applications.

Final Drives. Feature planetary reduction
at each wheel. Torque is developed at
the wheel, which offers less stress at the
axle shafts. The planetary units can be
removed independently from the wheels
and brakes.

5 Heavy-Duty Axles. Feature optional axle
oil coolers, permanently lubed universal
joints and stronger axle components in
both the differentials and final drives for
increased performance, serviceability
and durability. Conventional differential
is standard.

Free-Floating Axle Shafts. Can be
removed independent of the wheels
and planetaries for quick and easy
serviceability.

Optional Axle Oil Cooling System.

Features two circuits that circulate oil
from the differentials through an oil­to-air cooler and filter and back to the
brakes. This system provides increased
oil life and improves component
performance and durability. The system
automatically turns on and off at a
preset oil temperature.

6 Axle-Shaft, Oil Disc Brakes.

Are adjustment-free, fully hydraulic
and completely sealed. Disc face
grooves provide cooling even when
brakes are applied for long, fade­resistant service life.

• Location of the brakes improves
serviceability. The axle shaft brake
design allows brake service while
leaving the final drive intact.

• Axle-shaft brakes require less force
by operating on the low torque side
of the axle. Combined with improved
axle oil circulation for increased
cooling, the oil-enclosed, multiple­disc brake design improves durability.

• Parking brake is spring-applied, oil­released and dry disc. It is mounted
on the transfer gear output shaft.
Manual override is possible to allow
movement of the machine.

Secondary Brakes. Are fully modulated
and the front and rear service brake
circuits are isolated so one circuit
can operate if pressure drops in
the other circuit.

Service Brakes. Are four-wheel,
hydraulic, oil-dipped, multiple disc
brakes that are adjustment-free,
completely enclosed and allow
modulated engagement without
slack adjusters.

B

r

a

k

e

s

(

2

0

%

R

i

m

p

u

l

l

)

100% Rimpull

Selected

Left Pedal

20% Rimpull

Selected

7

1 Electro-Hydraulic Control System.

Increases hydraulic efficiency and
enhances operator comfort through
low-effort, fingertip controls. XT-3™
and XT-5™ hose along with reliable
components reduce the risk of leaks
and blown lines, helping protect
the environment.

2 Lift and Tilt System. Consists of
larger bore lift and tilt cylinders and
a two position main hydraulic pump,
contributing to increased performance
and serviceability.

Two Position Main Hydraulic Pump.

Is controlled by the Electronic Control
Module (ECM). A solenoid valve
controls the pump displacement, allowing
the ECM to adjust hydraulic flow during
the loader cycle. This strategy results in
fast hydraulics and greater lift forces,
leading to optimized performance.

3 Load Sensing Steering. The STIC
control system integrates the steering
and transmission into a single controller.
A STIC operated, pilot valve controls the
flow to steering cylinders. The steering
system utilizes a variable displacement
pump for maximum machine performance
by directing power through the steering
system only when needed.

4 Case Drain Filtration. A total of
three filters for the main hydraulic,
steering and fan pumps protect against
contamination with easy access
for service.

8

Efficient, well-balanced hydraulics and low-effort electronic controls mean high
performance and exceptional durability.

Hydraulics and Electronic Monitoring

1

5 Demand Fan. A speed controlled,

hydraulic fan provides maximum
cooling efficiency by directing the
appropriate amount of power through
the fan system based on the system’s
temperature.

Advanced Electronics. Play a major
role in the operation of the 988H.
Productivity improvements, enhanced
serviceability, increased operator
efficiency and lower costs are direct
benefits of the 988H advanced
electronics.

6 Caterpillar Monitoring System (EMS-III).

Continually monitors various machine
systems through three instrument clusters
and provides a three-level warning
system to alert the operator of immediate
or pending problems. It shares information
with the engine, hydraulic and transmission
controls that can be used during servicing
to simply service and troubleshooting.
The Caterpillar Monitoring System also
allows for new software to be uploaded
directly into the cab.

Optional Payload Control System.

Tracks data regarding the load in the
bucket. It also features a numeric keypad
and easy to view display. An available
printer makes onboard ticket printing
possible.

Optional Ride Control. Provides a
boom suspension system by placing
two accumulators in the boom circuit,
reducing fore and aft pitch over rough
terrain. This results in a smoother,
more comfortable ride, allowing higher
load and carry speeds, increased load
retention and component life.

Loose Material Mode. Provides maximum
hydraulic speed and efficiency for loading
in easily penetrated loose material.

9

6