Hitachi EX1900-5 Operator's Manual page 238

Check Grease Level --- daily
Remove two wing nuts (4). Open grease-can top cover
assembly (5) to check quantity of grease inside. Add
grease if necessary.
Automatic Greasing
Move auto-lubrication toggle switch (1) to the AUTO LUB.
position. Disconnect hose (6) at coupler (7). The grease
pump intermittently delivers grease for approximately
one minute with an interval of 3 minutes according to the
greasing schedule preset at the factory. The greasing
schedule, interval and volume, can be adjusted as shown
below.
IMPORTANT: Do not adjust greasing interval to be too
long or the greasing volume to be too
small.
MAINTENANCE
5
7-106
1
7
6
4
M146-07-107
M18C-07-011
M141-07-017