Operation Description
48
2.18.2 Hydraulic Hitch System Faults and Troubleshooting
Table 2-7 Hydraulic Hitch System Faults and Troubleshooting
Fault
Causes
Troubleshooting
Unable to lift
either a light or
heavy load
(1) The oil level within the 3-point lift
is too low
(2) The strainer of the oil filter is blocked
(3) Air is getting into the oil suction line
(4) Gear oil pump failure
(5) Spring pin on the outside/inside end
of the operation handle has fallen out
(6) The swing rod inside the hydraulic
distributor dropped
(7) The main control valve seized at the
middle or lowering position, or the oil
return valve seized in the open position
(8) Main control valve seized
(9) Lowering valve seized
(10) Pin shortened, or lowering valve
assembly comes loose making it unable
to open the lowering valve
(11) The oil circuit from the cylinder end
to oil cylinder is closed
(1) Add oil to the specified oil level
(2) Clean or replace the strainer on the oil filter
(3) Check for air leaks
(4) Replace the geared oil pump
(5) Reinstall the spring pin
(6) Open the distributor, and install the
swing rod
(7) Take apart the distributor, and clean
each valve
(8) Clean main control valve
(9) Clean lowering valve
(10) Remove plug for lowering valve, readjust
the clearance of the lowering valve push pin or
tighten the lowering valve assembly
(11) Open the oil circuit
Light load can
be lifted, but
heavy load
cannot be lifted
or lifts slowly
(1) Air is entering the oil suction line
(2) Adjustment pressure of the system
safety valve is too low
(3) Adjustment pressure of the oil
cylinder safety valve is too low
(4) Gear oil pump is worn or pressure
is inadequate
(5) Oil cylinder seal ring is leaking
(1) Check the oil suction pipe and oil filter
(2) Replace the system safety valve
(3) Replace the oil cylinder safety valve
(4) Replace the geared oil pump
(5) Replace the seal ring on the oil cylinder
Farm
implements
shake during
lifting and/or
lift slowly
(1) Oil filter is blocked
(2) Air getting into the oil suction pipe
(3) Gear oil pump failure
(4) Hydraulic oil level is too low
(1) Replace the filter element
(2) Replace the O-ring seal
(3) Replace the gear oil pump
(4) Add lubricating oil according to
the requirements
Farm
implements
slowly drop after
being lifted, and
the descent
becomes faster
after turning off
(1) The tightness of the check valve in
the hydraulic flow hydraulic flow
distributor is poor
(2) The lowering valve is not
sealed tightly
(3) The oil cylinder safety valve leaks oil
or is not adjusted properly
(1) Clean the check valve, and lap it-in
if necessary
(2) Clean or lap in the lowering valve
(3) Repair or readjust the safety valve on the
oil cylinder
(4) Replace the O-ring
(5) Check and replace the seal ring
