Milton CAT 990H - Manual (Page 12)

12
Two Separate Hydraulic Systems.
Improve the cooling and help prevent
cross-contamination. One system is for
lift/tilt and brakes, while the other is for
the steering and engine cooling fan.
If one system runs hot or is contaminated,
the other will be unaffected.
Fast Cycle Times. With a high pressure
system make the 990H remarkably
productive. Just 9.2 seconds to raise,
2.9 seconds to dump and 3.8 seconds
to lower.
High Pressure Hydraulic System.
With main lift/tilt relief of 31 000 kPa
(4,500 psi). Main lift/tilt controls are
driven by fixed displacement piston
pumps built by Caterpillar for optimum
pressure was increased for better
response. XT™-3 and XT™-6 hose is
used on the entire machine except for
the pilot lines and reusable coupling
with o-ring face seals are reliable and
reduce the risks of leaks.
Load-Sensing Steering System.
Maximizes engine power. Typical
steering systems can draw more than
30 kW (40 hp) from the engine. The draw
is constant even when the operator is not
steering. The system maximizes
performance by directing power through
the steering system only when it is needed.
For example, in hard digging, when the
machine is not steering, all engine power
is available to generate crowd, breakout
and lift forces. More efficient use of
power results in decreased fuel
consumption and higher production.
Hydrostatic Cooling Fan. Is used for
engine, transmission and hydraulic cooling.
A variable displacement pump drives the
fan’s hydraulic motor so that fan speed
varies with engine rpm. With the optional
high ambient cooling package, the pump
increases output as temperatures increase
for greater cooling capability. The fan
draws only the power needed for cooling,
reducing fuel consumption and
increasing efficiency.
Powerful hydraulics are the invisible force behind the loader’s muscle and flexibility.
Hydraulic System