Control Levers; Hydraulic System - Hitachi EX1900-5 Operator's Manual

Problem
Moves Hard
Does Nothing
Does Not Return to Neutral
Too Much Play
Lever is Not Vertical In Neutral
Problem
Hydraulic Functions are Slow
Hydraulic Oil Overheats
TROUBLESHOOTING

CONTROL LEVERS

Cause
Corroded joint
Worn out pusher
Worn out pusher
Pilot valve
Pilot valve
Worn out pivot joint
Pilot valve

HYDRAULIC SYSTEM

Cause
Low oil level
Cold oil
Wrong oil
Engine speed too low
Pilot circuit
Worn pump
Restricted pump suction line
Wrong oil
Air leak in pump suction line
Oil lines restricted
Low oil level
Plugged filters
Worn pump
Plugged radiator or oil cooler
Oil cooler bypass
Relief valve
Contaminated oil
Improperly adjusted hydraulic
components
11-10
Solution
See your authorized dealer.
See your authorized dealer.
See your authorized dealer.
See your authorized dealer.
See your authorized dealer.
See your authorized dealer.
See your authorized dealer.
Solution
Fill reservoir to full mark.
Warm up hydraulic oil to normal cycle
times.
Drain tank. Use correct oil.
Increase speed or see your authorized
dealer.
See your authorized dealer.
See your authorized dealer.
See your authorized dealer.
Use correct oil.
See your authorized dealer.
See your authorized dealer.
Fill reservoir to full mark.
Install new filters.
See your authorized dealer.
Clean and straighten fins.
See your authorized dealer.
See your authorized dealer.
Drain oil and refill.
See your authorized dealer.