Hyundai HX130LCR Manual page 345

6) BOOM MAKES A SQUEAKING NOISE WHEN BOOM IS OPERATED
YES
Is boom foot pin
greased
sufficiently?
NO
6-22
Cause Remedy
Frictional noise
occurs between
the sliding faces
of boom
cylinder's oil
seal and boom
proper.
※ Frictional
noise will
disappear if
they are kept
used.
Boom foot pin Supply grease
has run out of to it.
grease.
※ If seizure is
in an initial
stage, supply
sufficient
grease.
If seizure is
in a grown
state, correct
it by paper
lapping or
with an oil
stone.