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Massey Ferguson 8140, 8160 tractor hydraulic system - Oil decontamination
The correct operation and performance of the Massey Ferguson 8140, 8160 hydraulics system is closely linked to the use of clean transmission oil.
When maintenance is carried out on the gearbox / axle assembly (e.g. brake or transmission repairs) this contaminates virtually the whole hydraulic circuit.
It is therefore essential to carry out a decontamination operation after
repairs in order to avoid the rapid deterioration of other components in
the circuit caused by the movement of particles carried by the oil.
The contamination of oil can result in:
- seizure or leaks in the steering spool valve (Orbitrol)
- seizure of the spool valves in the solenoid valves
- excessive wear in the hydraulic pump(s).
The aim of oil decontamination is to restore the hydraulic circuit to a
state of cleanliness higher than that before the repair operation.
The
particles that cause the
greatest damage are not the largest ones, for these are rapidly caught
in the filter, it is the repeated circulation of small non-filtered
particles that has the greatest
abrasive effect.
Decontamination procedure
The decontamination is carried out in two distinct phases.
The static phase
- This takes place immediately after the repair operation, without
moving the tractor.
- Check that the oil has been replaced after the repair operation.
- During this phase, no low-pressure components should be activated.
- The decontamination is carried out by circulating the contaminated oil
to the housing return through filter elements in order to rapidly remove
any particles
suspended in the oil.
Preparation of the MF 8140, 8160 tractor
The equipment used for oil decontamination is two hose pipes of a
suitable length fitted with a female diagnostics connector, on one of
the ends.
Disconnect the temperature switch (3) (Heavy Duty transmission) and ground it to earth in order to neutralise its action.
Connect the female diagnostics connector of each hose pipe on the male connectors (1) (2) of the lowpressure circuit.
These connectors are
respectively located
on the right-hand side hydraulic cover, on the clutch valve or the
Reverse Shuttle hydraulic control unit, depending on the version.
Fasten the other end of the hose pipes without connectors to the return
port R.
Decontamination
The oil temperature must be above 10° C to avoid the opening of the
by-pass. Start the engine and run it at 1200 rpm.
Allow the engine to run for 15 minutes minimum in order to filter out
the particles in the oil.
Check that the clogging indicator lamp on the
dashboard does not light
during the decontamination operation. If this does happen, replace the
15-micron filter element and check or change the suction strainer.
After having let the engine run for 15 minutes, stop the engine and
replace the 15-micron filter by a 6-micron filter. Procure a hose pipe
of appropriate strength, fitted
at each end with a male quick-disconnect coupling for connection to the
auxiliary spool valves.
Connect the connectors of the flexible to ports A and B of the same
spool valve. Start the MF 8160, 8140 engine and run it at 1200 rpm.
While the engine is running, turn the knurled knob of the spool valve to maximum flow and alternate the direction of oil circulation in the spool valve for approximately 5 minutes using the control lever.
Repeat the operation on the two or
three other spool valves (depending on options). If the clogging indicator lamp lights on the dashboard, replace the
6-micron filter element by another of the same type.
Dynamic phase - Contrary to the static phase, the dynamic phase uses all
the hydraulic functions of the tractor for 15 minutes with the engine
running: lift control,
steering, power take off, brakes and etc.
Preparation of the Massey Ferguson 8160, 8140 tractor
Remove all the hose pipes used during the static phase.
During decontamination, carefully monitor the dashboard clogging
indicator. If necessary, immediately replace the 6-micron filter and the
suction strainer.
Raise and lower the lift arm over the entire travel of the rams and carry out a rapid alternating raise and lower cycle. Turn the steering wheel to full lock in both directions several times.
Declutch and allow the clutch in and out 5 or 6 times using the full travel of the pedal (tractors with Heavy Duty transmission). Repeat the same operation again more quickly.
Press and release each of the
unlatched brake pedals several times. Repeat the same operation more
quickly. Slowly press
and release the latched pedals several times. Repeat the same operation
again more quickly.
Activate the Dynashift control, located on the left beneath the steering
wheel, moving it from A to D and vice versa several times. Operate and
halt the power take
off 4 or 5 times, one after another. Reconnect the temperature switch.
Carry out a road test the tractor using various engine speeds, changing
up and down through the ratios for approximately 15 minutes.
When the road test is completed, let the engine run at 1200 rpm for
approximately 15 minutes with the tractor stationary, in order to
eliminate any remaining particles
in the circuit.
Preparing the MF 8140, 8160 tractor for service
When all these operations have been completed, prepare the tractor for
service by replacing the suction strainer and the 6-micron filter used
for decontamination
with a new and original spare parts suction strainer and 15-micron
filter, as referenced in the Spare Parts catalogue.
(1) Decontamination connectors (low pressure), (2) Decontamination
connector on clutch valve or Power shuttle hydraulic control unit (Heavy
Duty transmission),
(3) Temperature switch (Heavy Duty transmission), (4) Oil
decontamination replaceable oil filter element (6 micron), (5) Clogging
indicator, A - Pressure Load ed -
Mechanical reverse shuttle version, B - Reverse shuttle version
(1) Decontamination connectors (low pressure), (4) Oil decontamination
replaceable oil filter element (6 micron), (5) Clogging indicator
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