TRANSMISSION AND TORQUE CONVERTER 5540F/YB5515 SERVICE MANUAL
7-24 Published 10-21-2010, Control# 198-04
Converter Out Pressure/Oil Cooler Flow Rate
1. Stop engine, connect a 0-145 psi (0-1000 kPa) pressure
gauge and flowmeter (see note) into the converter out
line as shown at E and H respectively.
NOTE: The flowmeter must have a low back pressure,
otherwise an incorrect reading will be obtained.
2. Run the engine at 1000 rpm with transmission in neutral.
The pressure gauge indicates the Converter Out
Pressure and the flowmeter indicates the Oil Cooler
Flow Rate, both readings should be as specified in
Technical Data, page 7-1.
3. Repeat step 2 and note gauge readings with engine
running at 2000 rpm.
4. Stop engine, remove test gauges and refit hoses to
original position.
If the pressure is low, refer to the fault Low Converter Out
Pressure for a list of possible reasons. A high pressure
together with low flow could be caused by a blocked oil
cooler.
Converter In Pressure
1. Stop engine, connect a 0-145 psi (0-1000 kPa) pressure
gauge to test point D.
2. Start the engine and run at 1000 rpm. With the
transmission in neutral the pressure gauge will show
Converter In Pressure which should be as shown in
Technical Data, page 7-1. A high or low reading could
indicate a faulty converter relief valve, or a problem with
the pump.
3. Remove pressure test gauge
Converter Relief (Safety) Valve Pressure
1. Connect a 0-145 psi (0-1000 kPa) pressure gauge to
test point D.
2. Fit a load valve J into the converter out line.
3. Start the engine and run at 1000 rpm. With the
transmission in neutral, slowly screw down the load
valve J while observing the gauge reading which should
rise to the Converter Relief (Safety) Valve setting as
specified in Technical Data, page 7-1.
4. If the reading is higher than specified then the converter
relief valve is faulty. A low reading indicates a leaking
pump seal or a faulty converter relief valve.
5. Stop engine, remove test gauges and refit hoses to
original position.
Lubrication Pressure
1. Stop engine, connect a suitable pressure gauge into the
return line from the oil cooler to the transmission as
shown at G.
2. Start the engine and run at 1000 rpm. With the
transmission in neutral the pressure gauge will indicate
the Lubrication Pressure which should be as specified in
Technical Data, page 7-1.
3. Repeat step 2 and note gauge readings with engine
running at 2000 rpm.
4. Stop engine and remove pressure gauge
Torque Converter Stall Test
NOTE: Before completing the torque converter stall test,
make sure that the mainline and clutch pressures
are correct. If the pressures are incorrect, the
clutches could slip, causing premature wear of the
clutch friction plates.
Also, make sure that the machine neutral circuit pressure
(including steer circuit) is correct 200 psi (1379 KPa)
maximum.
1. Ensure that the engine and transmission are at normal
working temperature. Run engine at maximum speed
and check the No Load Speed (High Idle Speed). See
Engine Technical Data for correct figure; adjust if
necessary.
2. Apply parking brake and footbrake firmly, select 4th
Speed Forward and open throttle fully. Engine speed
should be as specified at Torque Converter Stall in
Transmission Technical Data. Select Reverse and
repeat test.
DO NOT stall the converter for longer than 30 seconds or the
transmission fluid will overheat.
3. If engine speeds are higher than the stated figures
check the transmission for clutch slippage or internal
leakage.
If engine speeds are below the stated figures either the
engine is losing power and should be serviced/
overhauled or the torque converter reaction member
clutch is slipping.
NOTE 1: The engine can also be checked by doing a stall
test and 'blowing off the main relief valve
simultaneously. The speed should be as stated
in Technical Data ('Engine Rev/Min at Converter
Stall + MRV Operating).
CAUTION
Make sure the load valve is in the OPEN position (the
adjusting knob screwed fully out) before starting the
following pressure test. If the load valve is not fully open,
damage to the converter seals will be incurred.
DO NOT allow the pressure to exceed 7.6 bar (110 psi) or
damage to the converter seals will be caused.
Reference Only
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