854K Wheel Dozer and 992K Wheel Loader Power Train Caterpillar

Torque Converter Lockup Clutch Pressure - Test

Usage:

992K 880

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Illustration 1	g02699080
Hydraulic system schematic (1) Priority valve (2) Lockup clutch solenoid valve (if equipped) (3) Impeller clutch solenoid valve (4) Transmission hydraulic controls (5) Oil filter (6) Oil filter (7) Torque converter (8) Lockup clutch (if equipped) (9) Impeller clutch (10) Oil pump (11) Torque converter outlet relief valve (12) Flow control orifice (13) Magnetic screen (14) Oil cooler (15) Reservoir in output transfer gear case (16) Outlet line from oil cooler to planetary lubrication (A) Oil pump output pressure tap P1 (B) Pressure tap for oil pump (C) Pressure tap for lockup clutch (if equipped) (D) Torque converter inlet pressure tap P3 (E) Pressure tap for oil pump (F) Pressure tap for impeller clutch (G) Lubrication pressure tap (H) Torque converter outlet pressure tap

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Illustration 2	g00107979
992K Wheel Loader Torque Converter Cover (C) Pressure tap for lockup clutch (if equipped). (F) Pressure tap for impeller clutch.

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Illustration 3	g00411458
Transmission (D) Torque converter inlet pressure tap P3.

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Illustration 4	g00107981
992K Wheel Loader Torque Converter Cover (H) Torque converter outlet pressure tap.

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NOTICE

Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting, and repair of the product. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids. Refer to Special Publication, NENG2500, "Dealer Service Tool Catalog" for tools and supplies suitable to collect and contain fluids on Cat^® products. Dispose of all fluids according to local regulations and mandates.

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Personal injury or death can result from sudden machine movement.
Sudden movement of the machine can cause injury to persons on or near the machine.

Prevent possible injury by performing the procedure that follows before working on the machine.

Park the machine on a smooth level surface.
Shift the STIC transmission direction control switch to the NEUTRAL position.
Lower the bucket and/or the attachment to the ground. Lower the blade and/or the attachment to the ground.
Engage the parking brake.
Place blocks in front of the wheels and behind the wheels.
Install the steering frame lock.
Allow only authorized personnel on the machine. Keep unauthorized personnel off the machine and in clear sight of the operator.

Note: All tests and all adjustments must be made while the transmission oil is at normal operating temperature.

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NOTICE

Do not connect or disconnect hose fittings to or from the quick disconnect nipples when there is pressure in the system. This will prevent damage to the seals that are in the fitting.

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Illustration 5	g00107976
Outlet Relief Valve (11) Torque converter outlet relief valve. (17) Spacers.

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Table 1
Torque Converter Pressure
Pressure	Pressure Tap	Pressure at High Idle	Adjustment
Lockup Clutch Hold Pressure (If equipped)	(C)	Minimum pressure is: 1965 kPa (285 psi) Maximum pressure is: 2100 kPa (305 psi)	-
Torque Converter Inlet	(D)	Maximum pressure with cold oil is 930 kPa (135 psi).	-
Impeller Clutch (Pedal Released)	(F)	Impeller clutch pressure is 1980 ± 300 kPa (285 ± 44 psi).	-
Impeller Clutch (Pedal Depressed)	(F)	Minimum pressure is 356 kPa (50 psi). Maximum pressure is 657 kPa (95 psi).	-
Torque Converter Outlet	(H)	Torque converter outlet pressure is: 70 ± 10 kPa (10 ± 1.5 psi).	Add spacers (17) or remove spacers (17).

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Table 2
Pressure Change for One Spacer⁽¹⁾
Description	Thickness	Pressure Change	Part

5M-9623 Spacer	0.91 mm (.036 inch)	18.2 kPa (2.64 psi)	Output Relief Valve (11)
5M-9624 Spacer	0.25 mm (.010 inch)	5.0 kPa (.73 psi)

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⁽¹⁾	Before an adjustment is made to outlet relief valve (11), make sure that the valve springs are not weak or broken.

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Table 3
Required Tools
Part Number	Description	Quantity
1U-5481	Pressure Gauge Group	1
1U-5482	Pressure Adapter Group	1

Lockup Clutch Disengaged (Minimum clutch pressure)

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The drive shaft rotates between the torque converter and the transmission whenever the engine is running. Contact with the rotating shaft can result in personal injury or death.

The rotating shaft is located under the implement and steering pumps. Do not allow personnel into the pump bay area behind the cab when the engine is running.

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Personal injury or death can result from sudden machine movement.
Sudden movement of the machine can cause injury to persons on or near the machine.

To prevent injury or death, make sure that the area around the machine is clear of personnel and obstructions before moving the machine to perform the test that follows.

Install a hose and a 4130 kPa (600 psi) pressure gauge on pressure tap (C).
Engage the parking brake and shift the transmission to neutral. Start the engine and run the engine at high idle.
Observe the pressure gauge. The pressure reading on the gauge must be 170 kPa (25 psi) or less.

Lockup Clutch Engaged (Maximum stabilized pressure)

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The drive shaft rotates between the torque converter and the transmission whenever the engine is running. Contact with the rotating shaft can result in personal injury or death.

The rotating shaft is located under the implement and steering pumps. Do not allow personnel into the pump bay area behind the cab when the engine is running.

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Personal injury or death can result from sudden machine movement.
Sudden movement of the machine can cause injury to persons on or near the machine.

To prevent injury or death, make sure that the area around the machine is clear of personnel and obstructions before moving the machine to perform the test that follows.

Install a hose and a 4130 kPa (600 psi) pressure gauge on pressure tap (C).
Remove the steering frame lock.
Remove blocks from the wheels.
Move the on/off switch for the torque converter lockup clutch (if equipped) to the ON position.
Engage the parking brake and place the transmission in neutral. Start the engine.
Apply the service brakes and release the parking brake. Place the 992K Wheel Loader in second speed forward. Place the 854K Wheel Tractor in second speed forward.
Operate the machine at maximum speed and observe the pressure reading on the gauge. Make sure that the torque converter pedal is not depressed. If the torque converter pedal is depressed, the lockup clutch is not engaged. The maximum stabilized pressure must be 1965 kPa (285 psi) to 2100 kPa (305 psi).