Hyundai r35z-7 Workshop Manual page 202

2)
B B OOM, ARM OR BUCKET SPEED IS LOW
YES
Is speed low only
in composite
operation?
Are LH/RH travel
speeds within
NO
standard levels?
Is MCV pilot
pressure within
standard level?
Is primary pilot
pressure within
standard level?
Is engine
revolution within
standard level?
Is not orifice in
control valve
clogged?
YES
Is combination
of oil streams
YES
normal at boom
hoisting and at
arm extrusion?
NO
YES
Are both LH/RH
travel speeds
NO
low?
NO
YES
Does control
YES
valve spool move
lightly by hand?
NO
YES
Is not MCV pilot
pressure piping
clogged or is not
NO
there oil leakage?
NO
YES
NO
Is gear pump
delivering oil?
NO
NO
YES
YES
Is pilot piping not
clogged or is oil
not leaking from
NO
the piping?
NO
5-19
YES
Are other
attachment
speeds within
standard levels?
NO
YES
Flow summation
Does spool of flow
check valve spool
summation check
is stuck.
valve move lightly
by hand?
NO
Hydraulic pump is
faulty.
YES
Is MCV pilot
pressure within
standard?
NO
OK
Does the
Port relief valve is
symptom change
faulty.
when port relief
valve is replaced
Cylinder is faulty.
with other valve?
NO
Control valve spool
is stuck.
Pilot valve is
defective.
Pilot relief valve is
faulty.
Gear pump is
broken.
Is pilot valve
Pilot valve is faulty.
normal?
NO
Cause Remedy
Normal.
Disassemble and
repair.
Disassemble and
repair.
Disassemble and
repair or replace.
Disassemble and
repair.
Disassemble and
repair.
Clean pilot piping
interior or repair
piping.
Disassemble and
repair.
Disassemble and
repair or replace.
Disassemble and
repair.
Adjust engine
revolution.
Clean orifice in
control valve.
Clean pilot piping
interior or repair
piping.
Disassemble and
repair.