Service Manual User Manual

Hydraulic System
9-117
9.11 TROUBLESHOOTING
This section provides an easy reference guide covering
the most common problems that occur during operation
of the hydraulic system.
Hydraulic System Troubleshooting
Problem Cause Remedy
1. Cannot lower elevated
load.
1. Ruptured hoist or extend hose.
2. Loss of engine power or
hydraulic pump failure.
3. Faulty components in hoist/lower
circuit.
4. Failed selector valve solenoid.
5. Failed joystick pilot valve.
1. Lower load using Emergency
Boom Lowering instructions in
Section 3 Boom
.
2. Lower load using Emergency
Boom Lowering instructions in
Section 3 Boom
.
3. Lower load using Emergency
Boom Lowering instructions in
Section 3 Boom
. Troubleshoot
components; repair or replace.
4. Replace selector valve
solenoid.
5. Replace joystick pilot valve
assembly.
2. Cavitation and noise. 1. Fluid level in reservoir is low.
2. Filter/breather is clogged.
3. Air leaks in suction line.
4. Loose pump mounting
hardware.
5. Loose pump sections.
6. Defective pump.
1. Add fluid. Refer to
Section 2
General Information,
Specifications and Maintenance
Instructions
.
2. Clean or replace filter/breather.
3. With the engine running, apply
a small amount of hydraulic
fluid on each joint of the suction
line and tighten any joint where
fluid stopped the noise. Double
clamp if necessary.
4. Torque the capscrews to 75 lb/ft
(102 Nm).
5. Determine cause of looseness.
Disassemble, clean, inspect,
repair and replace parts as
required. Torque pump
capscrews to proper
specification.
6. Repair or replace pump.
3. Ruptured hose. 1. Hose damaged due to tight
bend(s) or twists.
2. Excessive pressure.
1. Replace hose; install without
tight bends or twists.
2. Check and adjust pressure to
proper specification.
4. Hose cover separated
from hose casing.
1. Hose twisted at fitting during
installation.
1. Replace hose. Prevent hose
from twisting or turning as
fittings are tightened.
5. Hose fittings have dam-
aged threads.
1. Connections were cross-
threaded or over-tightened.
1. Replace hose. Install and
torque properly.
Model 3606 • Origin 10/99