6-7
Oil cooler clogged.
Bypass check
valve is defective.
ͽ
Replenish
specified oil to
the standard
level.
Clean oil cooler.
Replace
Adjust belt
tension or
replace belt.
Readjust set
pressure.
Reduce load.
YES
NO
Is hydraulic oil
volume proper?
Is oil cooler clogged
and is bypass check
valve always open?
Is main relief
valve used very
often?
Is not the set
pressure of main
relief, port relief
and travel relief
valve lower than
the standard
level?
Is fan belt
tension proper?
ͽ
YES
NO
YES
YES
YES
YES
NO
NO
NO
Drop hydraulic oil
sample on hot
plate and check if
foams come up.
Water is mixed.
Air is intruded.
Put hydraulic oil
still, separate
water and
dispose it or
replace hydraulic
oil.
Check suction
line and return
line and eliminate
the air intruding
source.
3. HYDRAULIC SYSTEM
HYDRAULIC OIL IS CLOUDY
1)
HYDRAULIC OIL TEMPERATURE HAS RISEN ABNORMALLY
2)
Cause
Remedy
Cause
Remedy