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

Torque Converter Impeller Clutch Pressure - Test

Usage:

854G 1JW

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Illustration 1	g00488440
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
992G 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
992G 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 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: The transmission oil must be at operating temperature before performing any test and any adjustment.

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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 (If equipped)	(C)	Stabilized pressure with an activated solenoid is 2000 kPa (290 psi) to 2137 kPa (310 psi). Pressure is less than 170 kPa (25 psi) when the solenoid is not activated.	-
Torque Converter Inlet	(D)	Maximum pressure with cold oil is 930 kPa (135 psi).	-
Impeller Clutch	(F)	Maximum pressure is 2585 ± 205 kPa (375 ± 30 psi). Pressure 2 seconds after a shift is 2050 ± 205 kPa (300 ± 30 psi). ⁽¹⁾ Minimum pressure is 620 ± 140 kPa (90 ± 20 psi). ⁽¹⁾	-
Impeller Clutch	(F)	Maximum pressure is 2482 ± 207 kPa (360 ± 30 psi). Pressure 2 seconds after a shift is 2050 ± 205 kPa (300 ± 30 psi). ⁽²⁾ Minimum pressure is 620 ± 140 kPa (90 ± 20 psi). ⁽²⁾	-
Torque Converter Outlet	(H)	Maximum pressure is 550 kPa (80 psi). Minimum pressure is 415 kPa (60 psi). (These pressures are for a machine in third speed, with activated brakes, with installed axle shafts, and with the converter in a stall condition.)	Add spacers (17) or remove spacers (17).

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⁽¹⁾	(S/N: 7HR1-Up; 1JW1-Up)
⁽²⁾	(S/N: A4W1-Up; AMP1-Up; ADZ1-Up; AZX1-Up)

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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

Maximum and 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.

Note: Make sure that the Left Service Brake Pedal Position Sensor is calibrated correctly before performing pressure tests. The test values can be affected if the Left Service Brake Pedal Position Sensor is not calibrated correctly.

Reference: Refer to the Service Manual module for Systems Operation, Testing and Adjusting, SENR1372, "Power Train Electronic Control System" for the calibration procedure for the 992G Wheel Loader Left Service Brake Pedal Position Sensor.

Reference: Refer to the Service Manual module for Systems Operation, Testing and Adjusting, RENR2143, "Power Train Electronic Control System" for the calibration procedure for the 854G Wheel Tractor Left Service Brake Pedal Position Sensor.

Note: Make sure that the Torque Converter Impeller Clutch Solenoid is calibrated correctly before performing pressure tests. The test values can be affected if the Torque Converter Impeller Clutch Solenoid is not calibrated correctly.

Note: The 854G Wheel Tractor is NOT equipped with the reduced/maximum rim pull feature.

Install a hose and a 4130 kPa (600 psi) pressure gauge on pressure tap (F).
Engage the parking brake and place the transmission in neutral. Start the engine.
Move the reduced/maximum rim pull switch (if equipped) to the MAXIMUM position.
Run the engine at high idle and observe the pressure reading on the gauge. The maximum pressure is 2050 ± 205 kPa (300 ± 30 psi) for (S/N: 7HR1-Up; 1JW1-Up). The maximum pressure for (S/N: A4W1-Up; AMP1-Up; ADZ1-Up; AZX1-Up) is 2050 ± 205 kPa (300 ± 30 psi).
With the engine at high idle, completely depress the left brake pedal and observe the pressure reading on the gauge. The minimum impeller clutch pressure must be 620 ± 140 kPa (90 ± 20 psi) or less.