Troubleshooting – Cub Cadet 8404 User Manual

Page 255

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HYDRAULIC SYSTEM

9-21

D615-W02 May-2003

Hydraulic cylinder rises irregularly

Hydraulic cylinder doesn’t

Elevating arm is positioned at
STOP and there is periodic
vibration with motor

ON: load not decreased with
motor OFF.

When working in the adjusted draft
stage, working machine responds
too sensitively.

Adjusted draft doesn’t operate and
hydraulic cylinder moves up and
down as the operation of position
lever.

Adjusted position doesn’t operate
and hydraulic cylinder moves up
and down

Hydraulic cylinder starts to rise but
stops as soon as load applied
(Relief valve not obstructed).

Hydraulic cylinder not fallen in
entire range.

Hydraulic cylinder not fallen.

Rising capacity not conform with
specification

Hydraulic cylinder supports the
load, but there is vibration
periodically: load decreased with
motor OFF.

* Lack in tank (mission case) oil

* Intake filter clogged

* Intake line mixed with air

* Sticking of control position

* Limit switch control of position

lever faulty

* MLS valve sensitivity control

faulty

* Draft control lever faulty

* Position lever control faultily

* Inside connection control faulty

* Power transmission tie rod (7)

faulty

* Position lever control faulty

* Sensitivity control faulty

* Sticking of OUTLET valve

* Poor sealing of MLS valve

* Relief valve and safety valve

control faulty

* Bad pump efficiency

* Bad efficiency of MLS valve

* Piston gasket worn

* Valve sensitivity faulty

* Relief valve faulty

* Down preventative valve faulty

valve.

Fill in oil to adequate level.

Clean or replace filter.

Check intake pipe, O-ring, and bolt
for looseness.

Disassemble MLS valve

Adjust control position and limit
the operation range of upper part.

Adjust sensitivity.

Adjust draft control.

Adjust position lever.

Disassemble hydraulic cylinder.

Adjust draft control.

Adjust position lever.

Adjust sensitivity.

Disassemble MLS valve
and clean OUTLET valve.

Disassemble MLS valve
and clean OUTLET value.

Disassemble MLS valve
and replace inside seal ring.

Replace gasket.

Adjust sensitivity or replace valve.

Disassemble and replace MLS
valve.

Trouble

Probable Cause

Remedy

12. TROUBLESHOOTING

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