Komatsu Components
Komatsu manufactures engine, torque converter, transmis-
sion, hydraulic units, and electrical devices on this dump truck.
Komatsu dump trucks are manufactured with an integrated
production system under a strict quality control system.
High Strength Body
The side plates of the body are reinforced with cross ribs to
increase the rigidity. The ribs of the bottom plate also increase
the rigidity greatly. Furthermore, the body is made of new steel
which we developed in cooperation with a Japanese steel
manufacturer having the best steel manufacturing technolo-
gies in the world. This ultra hard
wear-resisting steel has hard-
ness 25% higher than the con-
ventional steel and about 2.5
times higher than the common
lining steel.
Sealed DT Connectors
Main harnesses and con-
troller connectors are
equipped with sealed DT
connectors providing high
reliability, water resistance
and dust resistance.
High-Rigidity Frames
Cast-steel components are used in the main frame for high-
stress areas where loads and shocks are most concentrated.
It provides a superior reliability and durability.
Flat Face-to-Face O-Ring Seals
Flat face-to-face O-ring seals
are used to securely seal
hydraulic hose and fuel line
hose connections and to pre-
vent oil or fuel leakage.
E
XCELLENT
R
ELIABILITY AND
D
URABILITY
5
4
O
F F
- H
I G H W A Y
T
R U C K
HD255-5
25mm 0.98"
14mm 0.55"
16mm 0.63"
O-ring
Nipple
Hose
Cast steel
E
ASY
M
AINTENANCE
Extended Oil Change Intervals
In order to minimize operating costs, oil change intervals
have been extended.
Engine oil change intervals: 250 hours
/
/
500 hours
Wet Multiple-Disc Brakes
The wet multiple-disc brakes on rear wheels make mainte-
nance and adjustment unnecessary.
Flange Type Rim
The flange type rims provide easy removal/installation of the
tires.
Centralized Arrangement
of Filters and Greasing
Points
The engine oil filter and fuel fil-
ter are centralized on the left
side of the machine so that
they can be serviced easily.
The greasing points are also
centralized at two locations.
These filter and greasing main-
tenances can be done from the
ground level.
OFF-HIGHWAY TRUCK
HD255-5
V
ALUE-
E
NHANCING
O
PTIONS
ARSC (Auto Retard Speed Control)
ARSC, which enables to maintain the constant downhill trav-
el speed, is available as an option. It allows the operator to
simply set downhill travel speed. Even after setting the trav-
el speed, the operator can still adjust it finely at increments
of 1 km/h 0.4MPH per click (±5 km/h 3.1 MPH within max.
travel speed) to match the optimum speed for the slope.
Also, since temperature of retarder cooling oil is always mon-
itored, the speed is automatically lowered.
Settable range: 7 km/h 4.3 MPH to 45 km/h 28.0 MPH
Desiccant Type Air Dryer
Desiccant type air dryer is available as
an option. It enables to get rid of the
moisture and oil content in the com-
pressed air that are provided from the
air compressor. Therefore, reliability
and durability of the air circuit is
improved spectacularly.
Front Brake Ratio Valve
The front brake ratio valve lowers the air pressure at the be-
ginning of braking operations to limit the efficiency of the
front brake to reduce heating and wear of the brake pad. If
the brake pedal is pressed more than half, however, the air
presser isn’t lowered, but the front brake works as designed.
Automatic Greasing System
This releases operators and mechanics from burdensome
greasing work on the undercarriage. Maintenance time is
shortened, and productivity is enhanced.
Go down sloop at
constant speed
UP
SET
DOWN
CANCEL
Display of set travel speed
ARSC set lever
