Hitachi ZAXIS 30U-5N Operator's Manual page 236

Drain Fuel Pre-Filter (ZX50U-5N, 60USB-5N)
--- every 8 hours (before starting operation)
IMPORTANT: Drain fuel filter daily before staring
operation. The engine may be damaged if you do not
drain fuel filter daily.
Pre-filter has water separator function, these allow float (4) to
rise as water accumlates.
Be sure to drain daily the water accumulated in the filter untill
float (4) goes the bottom of case.
Drain Procedures
1. Park the machine following the same procedures as
described on page 7-6 for preparation for inspection and
maintenance.
2. Place 0.5 liters or larger capacity container under drain
valve (5) to collect the drained water.
3. Close cock (3) at upper part of fuel pre-filter (1). Loosen
drain valve (5) at lower part of fuel pre-filter (1) to drain
water. If water is difficult to drain, loosen air bleed plug
(2).
4. After draining water, securely tighten drain valve (5) and
plug (2).
5. Open cock (3).
IMPORTANT: After draining water from the water
separator, bleed air from the fuel supply system.
MAINTENANCE
7-56
1
MADG-07-001
2
3
4
5
MADG-07-002