Warming-Up The Motor And The Cylinders - Hitachi EX1900-5 Operator's Manual

Warming-up the Motor and the Cylinders

IMPORTANT: 1. In cold weather, be sure to thoroughly
warm-up the motors and cylinders.
2. If the hydraulic circuit is continuously
relieved for a certain amount of time,
the temperature in the control valve
would rise excessively. Never operate
to stroke end more than 15 seconds.
After relieving any function, up to 15
seconds, be sure to have a 5–10 sec-
ond intermission.
1. Run the engine for at least 5 minutes on slow idle.
2. Run the engine for at least 5 minutes at medium
speed. Extend the warming-up time when the atmos-
pheric temperature is extremely low by running the
engine at a middle speed.
3. As described above, warm the hydraulic oil by reliev-
ing the hydraulic oil pressure while rolling in the
bucket and raising the boom.
4. While warming the hydraulic oil by the method men-
tioned above, circulate hydraulic oil by slowly operat-
ing each cylinder of the boom, arm, and bucket full
stroke, and the swing motor in both directions, and
traveling the machine approximately 5 m distance
several times at an interval of 3 to 5 minutes.
IMPORTANT: If hydraulic oil is warmed only by reliev-
ing the relief valve, and/or if the warmed
hydraulic oil is suddenly delivered to the
cool hydraulic components such as mo-
tors and cylinders, damage to the hy-
draulic components may result. Be sure
to occasionally circulate hydraulic oil
through the motors and cylinders during
warming-up operation.
5. Before beginning work with the machine, sufficiently
operate each function of the front attachment, swing,
and travel circuits without a load so that the hydraulic
oil temperature in all the hydraulic circuits is equal.
OPERATING THE MACHINE
5-8
1
M146-01-010