Warming-Up Operation - Hyundai HL970A Operator's Manual

4. WARMING-UP OPERATION

4. WARMING-UP OPERATION
※
The most suitable temperature for the hydraulic The most suitable temperature for the hydraulic
oil is about 50˚C (11 oil is about 50 C (112˚F). It can cause serious
trouble in the hydraulic system by sudden oper- trouble in the hydraulic system by sudden oper-
ation when the hydraulic oil temperature is ation when the hydraulic oil temperature is
below 25 below 25˚C (7 C (77˚F). The temperature must be ˚F). The temperature must be
raised to at least 25 raised to at least 25˚C (77
work. work.
Run the engine at low idling for 5 minutes.
1)
Speed up the idling and run the engine at mid-
2)
range speed.
Push the pilot cut off switch to the ON position.
3)
Lift the boom slightly and extend the bucket cylin-
4)
der to the stroke end to relieve hydraulic pressure.
※
Do not leave hydraulic pressure relieved for Do not leave hydraulic pressure relieved for
more than 30 seconds. more than 30 seconds.
Shorten the bucket cylinder to the stroke end to
5)
relieve hydraulic pressure.
※
Do not leave hydraulic pressure relieved for Do not leave hydraulic pressure relieved for
more than 30 seconds. more than 30 seconds.
Repeat the procedure 4) - 5) several times until
6)
warm-up operation is completed.
˚F). It can cause serious
C (77˚F ) before starting F ) before starting
4-8
Gear selector lever
Parking brake switch
Pilot cut off switch
ON
5 minute
warming-up
960A4OP08