966M XE and 972M XE Wheel Loaders Power Train, Steering, Braking, Hydraulic, and Machine Systems Caterpillar

Transmission - Transmission Hydraulic Control Clutch Pressure Test

Usage:

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Hot hydraulic oil under high pressure can remain in the components of the hydraulic system or the power train system after the engine has been stopped. The uncontrolled release of the hydraulic oil can cause sudden machine movement and can also result in the following conditions:

Burns

The penetration of body tissue

Other personal injury

Death

If hydraulic oil penetrates body tissue, the injury must be treated immediately by a doctor who is familiar with this type of injury. Use a board or a piece of cardboard to check for a hydraulic oil leak. Make sure that all of the attachments have been lowered to the ground and that all trapped pressure has been released from the hydraulic system and the power train system. Also, make sure that the hydraulic oil is cool before the removal of any components or lines. Remove the hydraulic oil filler cap only when the engine is stopped and the filler cap is cool enough to touch with your bare hand.

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Personal injury or death can result from not engaging the parking brake.

Transmission engagement alone will not prevent machine from rolling when the engine is stopped.

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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.

Required Tools

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Illustration 1	g01106077
Tooling (A)

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Illustration 2	g01623868
Tooling (B) 198-4240 Digital Pressure Indicator Gp

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Table 1
Tool	Item	Part Number	Description	Qty
A	A1	8T-0854	Pressure Gauge (0 to 1,000 kPa (0 to 145 psi))	1
	A2	8T-0856	Pressure Gauge (0 to 6,000 kPa (0 to 870 psi))	1
	A3	6V-3989	Fitting	1
	A4	6V-4143	Quick Connect Coupler	2
	A5	177-7860	Hose As (3.0 m (10 ft))	1
B		198-4240	Digital Pressure Indicator Gp
	B1	198-4234	Indicator	1
	B2	198-4237	Pressure Sensor 3445 kPa (500 psi)	1
	B2	198-4239	Pressure Sensor 68900 kPa (10000 psi)	2
	B3	198-4236	Extension Cable	3

ReferenceRefer to Tool Operating Manual, NEHS0818, "Using the 198-4240 Digital Pressure Indicator Group" for more information on using Tooling (B) .

Machine Set Up

Park the machine on a smooth, level surface.

Place the transmission in the NEUTRAL position.

Lower the work tool to ground.

Engage the parking brake.

Place blocks in front of the wheels and behind the wheels.

Install the steering frame lock.

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Illustration 3	g02735362

Perform machine walk-around and check for any leaks or damage. Check transmission oil level and fill to proper level if necessary.

Allow only authorized personnel on the machine. Keep unauthorized personnel off the machine and in clear sight of the operator.

Run the engine and warm the machine to operating temperatures. Engine coolant and hydraulic oil should at normal machine testing temperatures.
Warm the transmission oil to normal operating temperature of approximately 83° ± 7°C (181° ± 12°F).
ReferenceFor more information about preparing a machine for troubleshooting, refer to the Service Manual module Testing and Adjusting, "Machine Preparation for Testing and Adjusting".

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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.

Test

Transmission Hydraulic Control Clutch Pressure Test

Use the following procedure to check Transmission Hydraulic Control Clutch Pressure Test

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Table 2
	Transmission solenoid #1	Transmission charge pressure	Transmission clutch #1 valve pressure	Transmission clutch #2 valve pressure
Both clutch valves commanded off	~0A	2580 ± 140 kPa (374 ± 20 psi)	0 ± 65 kPa (0 ± 9 psi)	0 ± 65 kPa (0 ± 9 psi)
Transmission clutch #1 commanded 50 percent	~1.0A	2580 ± 140 kPa (374 ± 20 psi)	1175 ± 250 kPa (170 ± 36 psi)	0 ± 65 kPa (0 ± 9 psi)
Transmission clutch #1 commanded 100 percent	~1.9A	2580 ± 140 kPa (374 ± 20 psi)	2551 ± 138 kPa (370 ± 20 psi)	0 ± 65 kPa (0 ± 9 psi)
Transmission clutch #2 commanded 50 percent	~1.0A	2580 ± 140 kPa (374 ± 20 psi)	0 ± 65 kPa (0 ± 9 psi)	1175 ± 250 kPa (170 ± 36 psi)
Transmission clutch #2 commanded 100 percent	~1.9A	2580 ± 140 kPa (374 ± 20 psi)	0 ± 65 kPa (0 ± 9 psi)	2551 ± 138 kPa (370 ± 20 psi)

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Illustration 4	g03696491

Select Transmission ECM for the machine that you are testing.

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Illustration 5	g03696682

Transmission ECM .

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Illustration 6	g03696683

Select Diagnostic Tests.

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Illustration 7	g03696700

Select Transmission Hydraulic Control Clutch Pressure Test

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Illustration 8	g03696726

Select Accept.

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Illustration 9	g03696742

When the set up conditions are met, click the "Next>" button to continue
Set up test conditions:
- Before starting the engine, connect pressure gauges to the clutch pressure ports and to the transmission charge pressure port.
Note: Transmission will shift into gear automatically during this test.
- Record the pressures indicated by the gauges.
Set Engine Speed to low idle.
Note: Engine Speed will be automatically adjusted during this test.
- Set the parking brake.
- Move the Shifter Lever to the Neutral Position.
- Fully release the throttle.
- The Transmission oil temperature must be greater than 40° C (104° F) to start the test.

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Illustration 10	g02735362

Insure that steering frame lock is installed.

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Illustration 11	g03679887

Use test ports on the front of the transmission at the articulation hitch for testing clutch (A) and clutch (B) .
(Clutch A) pressure test port. View from right side of machine at the articulation hitch.
(Clutch B) pressure test port. View from left side of machine at the articulation hitch.

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Illustration 12	g03696800

Record the specified values and then click the "Next>" button to continue.
- Transmission Solenoid #1 (Clutch A) is set to 0% current. Record the pressure indicated by the gauge. Click the "Next>" button to proceed to the next gear.

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Illustration 13	g03696804

Record the specified values and then click the "Next>" button to continue.
- Transmission Solenoid #1 (Clutch A) is set to 50% current. Record the pressure indicated by the gauge. Click the "Next>" button to proceed to the next gear.

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Illustration 14	g03696819

Record the specified values and then click the "Next>" button to continue.
- Transmission Solenoid #1 (Clutch A) is set to 100% current. Record the pressure indicated by the gauge. Click the "Next>" button to proceed to the next gear.

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Illustration 15	g03696821

Record the specified values and then click the "Next>" button to continue.
- Transmission Solenoid #2 (Clutch B) is set to 0% current. Record the pressure indicated by the gauge. Click the "Next>" button to proceed to the next gear.

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Illustration 16	g03696823

Record the specified values and then click the "Next>"Record the specified values and then click the "Next>" button to continue.
- Transmission Solenoid #2 (Clutch B) is set to 50% current. Record the pressure indicated by the gauge. Click the "Next>" button to proceed to the next gear.

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Illustration 17	g03696824

Record the specified values and then click the "Next>"Record the specified values and then click the "Next>" button to continue.
- Transmission Solenoid #2 (Clutch B) is set to 100% current. Record the pressure indicated by the gauge. Click the "Next>" button to proceed to the next gear.