Hitachi 210313 - Manual (Page 11)

11 307160
Troubleshooting
WARNING
To reduce the risk of serious injury whenever you
are instructed to relieve pressure, always follow the
Pressure Relief Procedure on page 8.
Before servicing this equipment, always make sure to
relieve the pressure.
NOTE: Check all possible problems and solutions
before disassembling the pump.
Problem Cause Solution
Pump fails to operate Restricted lines or inadequate hydraulic
supply Clear lines. Increase hydraulic supply.
Insufficient hydraulic pressure; closed
or clogged valves, etc. Open; clean.
Exhausted fluid supply Refill and reprime, or flush.*
Clogged fluid line, valves, etc. Clear.**
Damaged hydraulic motor Service the motor. See manual 307158
Dried fluid seizure of displacement rod. Clean. See Displacement pump manual
308043. ALso, keep TSL in the pump
wet-cup and stop the pump at the bot-
tom of its stroke during non-use.
Pump operates, but the fluid
output is low on both strokes Restricted lines, or inadequate hydrau-
lic supply Clear lines. Increase hydraulic supply.
Insufficient hydraulic pressure; closed
or clogged valves, etc. Open; clean.
Exhausted fluid supply Refill and reprime or flush.*
Clogged fluid line, valves, etc. Clear.**
Piston check valve needs adjustment Adjust. See manual 308043.
Packing nut too tight Loosen.
Loose packing nut or worn throat pack-
ings. Tighten packing nut or replace packings
as needed, See manual 308043.
Pump operates, but the output
is low on the downstroke The intake valve is stuck open or worn. Clear; service. See manual 308043.
Pump operates, but the output
is low on the upstroke The piston valve is stuck open, or the
packings are worn Clear; service. See manual 308043.
Pump is operating erratically,
or speeds up suddenly Exhausted fluid supply Refill and reprime or flush.*
The intake valve is stuck open or worn Check; replace parts as needed. See
manual 308043.
The piston valve is stuck open or the
packings are worn. Check; replace parts as needed. See
manual 308043.
Excessive hydraulic fluid supply volume Lower volume.
Air entrained in fluid Purge all air; change fluid.
* Stop the pump immediately if it is running too fast; check the fluid supply. If empty, refill and reprime the pump
being sure to eliminate all air from the system, or flush the pump and store it with an oil-based solvent, such as
mineral spirits, to prevent corrosion.
** Relieve the pressure, and then disconnect the fluid line. If the pump starts when the hydraulic power is re-
stored, line, etc. is clogged.