Hyundai r35z-7 Workshop Manual page 195

5) THE SWING UNIT DRIFTS WHEN THE MACHINE IS AT REST ON A SLOPE
YES
Is brake spring
normal?
Is return spring
of swing control
valve normal?
NO
Is swing relief
pressure within
standard level?
YES
Is swing shuttle
YES
valve normal?
NO
NO
YES
Is drain rate of
swing motor
YES
within standard
value?
NO
NO
5-12
Cause Remedy
Disassemble
Shuttle valve is
and replace.
faulty.
Disassemble
Brake spring is
and replace.
faulty.
Disassemble
Return spring of
and replace.
swing control
valve is faulty.
Disassemble
Swing relief valve
and repair or
is faulty.
replace.
Disassemble
Swing motor is
and repair.
broken.
Adjust swing
relief valve
pressure or
replace swing
relief valve.