Doosan DL160, Operation And Maintenance Manual

Page: 121 / 236

OP000755
3-9
Operation
7. Rotate starter key to "O" (OFF) position. Remove key.
Hydraulic System Warm-up
1. Correct operating temperature of hydraulic oil is 50° - 80°C
(120° - 175°F). Make sure to follow procedures listed
below for hydraulic fluid warm-up.
2. Run engine at idle (no load) for five minutes.
3. Run engine for approximately five minutes at middle of
speed range, without a load.
4. Cycle bucket until bucket cylinder bottoms out (extended
and retracted) without a load to circulate the oil through the
system. Do this for five minutes.
NOTE: Do not allow cylinders to pass hydraulic oil over
relief valve for more than twenty seconds at a
time.
5. Cycle boom, and bucket about five times without a load to
circulate oil through system.
Hydraulic System Warm-up – Cold
Weather
1. Follow Steps 1 through 3 in "Hydraulic System Warm-up."
2. Do not operate machine at full speed until system has fully
warmed up.
3. If working speeds continue to be slow, repeat initial
hydraulic warm-up procedures again. If repeating warm-up
procedures does not improve working speeds, continue to
operate, but use extreme caution because machine
function may be erratic.
FG003900
O
I
Figure 21