Gm Motor: Troubleshooting And Corrective Measures - Kubota KX080-3 Workshop Manual

WSM KX080-3 Service
7.Troubleshooting and corrective measures
Troubleshooting is not easy. Some assumed
causes are listed in the table below. Since repair is
difficult, refer to the assumed causes and
corrective measures in the table.
Symptoms, assumed causes, and corrective
measures in general are listed in the table below.
In most cases, a trouble isnot caused bya
Symptom
Secondary pressure does not
rise.
Secondary pressure is
unstable.
Secondary pressure is too
high.
Damping function does not
work.
Damping torque is large.
Shuttle valve does not work.
(RCVD8CC only)
Cause
[1] Insufficient primary pressure
[2] The secondary-pressure-setting spring (324) no
longer has enough elasticity.
[3] The gap between the spool and the casing is too
wide.
[4] The operating section is not fixed firmly.
[1] Sticking portion in siiding part
[2] Fluctuations in tank line pressure
[3] Air trapped in thepipe
[1] Tank line pressure is high.
[2] Stickingportion in siidingpart
[1] Air is trapped inside the piston chamber.
[2] Sticking portion in siiding part
[3] The damping springs (336, 337) no longer have
enough elasticity.
[4] The gap between the dampingpiston (224) and the
casing is too wide.
[5] Malfunction of the check valve
[6] The orifice of the damping piston is too large.
[1] Stickingportion in siiding part
[2] Clogging of the orifice in the damping piston.
Malfunction of the shuttle valve
failureonlywitha singlepart, but caused bya failure
involving more than one part.
For this reason, be aware of the fact that
corrections may also be necessary other than
listed.
Also, the table below does not cover al I the
assumed causes and corrective measures.
The persons in charge of repair must further
investigate problems and causes as necessary.
Correction
[1] Secure primary pressure.
[2] Replacewith a new one.
[3] Replace the spool and casing assembly.
[4] Disassemble, reassemble and replace the operat-
ing section component part.
[1] Correct the sticking portion.
[2] ReturntheoiI intotheoiI tank directly.
[3] Bleed the pipe several times.
[1] Return to the oiI into the oiI tank directly.
[2] Correct the sticking portion.
[1] Bleed the air several times.
[2] Correct the sticking portion.
[3] Replace with a new one.
[4] Replace the damping piston and casing assembly.
[5] Disassemble and investigate the check valve por-
tion.
[6] Replace the damping piston.
[1] Correct the sticking portion.
[2] Correct or replace the damping piston.
Disassemble and investigate the shuttle valve portion.
IV-S-112
Hydraulic system