21 - 2
Pressure and Flow Tests
Before completing any of the transmission pressure/flow
tests, make sure that the oil level is correct and at normal
operating temperature.
All gauges etc used in the following pressure/flow tests are
shown in Service Tools - Syncro Shuttle Gearbox.
!!
WARNING
Fine jets of hydraulic oil at high pressure can penetrate
the skin. Do not use your fingers to check for hydraulic
oil leaks. Do not put your face close to suspected leaks.
Hold a piece of cardboard close to suspected leaks and
then inspect the cardboard for signs of hydraulic oil. If
hydraulic oil penetrates your skin, get medical help
immediately.
HYD 1-1
!!
WARNING
Take care when disconnecting hydraulic hoses and
fittings as the oil will be HOT.
Trans 1-2
!!
WARNING
DO NOT go underneath the machine with the engine
running. Switch off the engine, apply the parking brake
and chock both sides of all wheels before going
underneath the machine.
Trans 2-1
TEST POINTS
A - Mainline pressure
B - Forward clutch pressure
C - Reverse clutch pressure
D - Converter inlet/converter relief valve pressure
E - Converter outlet pressure
F - Pump flow (remove filter and fit adapters)
G - Lubrication pressure
H - Cooler flow (flowmeter in line from transmission to
cooler)
J - Load Valve
If testing the complete transmission, the following
procedures are listed in a logical sequence and should
therefore be completed in the same sequence. Also, refer to
the Fault Finding procedures at the beginning of the
transmission section for reference to specific tests.
Mainline Pressure
1 Stop engine, connect a 0-20 bar (0-300 lbf/in
2
) pressure
gauge to test connector A.
2 Start engine and run at 1000 rev/min. With the
transmission in neutral the pressure gauge will show
the Mainline Pressure which should be as given in
Technical Data.
3 Repeat step 2 and note gauge readings with engine
running at 2000 rev/min.
4 Stop engine and remove test gauge.
If the mainline pressure is low, refer to Fault Finding 'Low
Mainline Pressure' for a list of possible reasons. A high
reading could indicate a faulty pressure maintenance valve.
Clutch Pressure (Forward Clutch Given in Example)
1 Stop engine, connect a 0-20 bar (0-300 lbf/in
2
) pressure
gauge to test connector B (item C for reverse clutch).
2 Start engine and run at 1000 rev/min. With parking
brake and footbrake firmly applied, select Forward, the
pressure gauge will show the Clutch Pressure which
should be as given in Technical Data.
Note: If the mainline pressure is in the lower part of the
tolerance band (refer to Technical Data), then the forward
and reverse clutch pressures should also be in the lower
part of the tolerance band and vice versa.
3 Repeat step 2 and note gauge readings with engine
running at 2000 rev/min.
4 Stop engine and remove test gauge.
If the clutch pressure is low, the clutch could be leaking. A
leaking clutch is easier to detect when the engine is running
at idle. With the engine at idling speed, check the mainline
pressure and then check the clutch pressure as described
above, if the clutch pressure is 1.7 bar (25 lbf/in
2
) less than
the mainline pressure, then the clutch is probably leaking.
Refer to Fault Finding 'Low Clutch Pressure', before
dismantling the clutch.
A high reading could indicate a faulty pressure maintaining
valve.
Section F Transmission
9803/7130
Section F
21 - 2
Issue 1
Service Procedures
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