963C Track-Type Loader Power Train Caterpillar

Transmission Stall - Test

Usage:

963C BBD

Show/hide table

The power train/hydrostatic transmission and the hydraulic system on this machine use the hydraulic tank as a common sump.
When the oil in the power train/hydrostatic transmission and hydraulic system gets hot, it causes the air to expand and build up pressure in the hydraulic tank.
Pressure can remain in the hydraulic tank after the engine and pumps are stopped.
Personal injury can occur if pressure is not released before any service is performed on the power train/hydrostatic transmission or the hydraulic system.
To prevent possible injury, remove the cap from the oil filler tube before any fitting, hose, or component in the power train/hydrostatic transmission or hydraulic system is loosened, tightened, removed, and/or adjusted.
The cap must be replaced when the tests and/or the adjustments are completed.
The bucket and the other attachments must always be flat on the ground before service is performed.
When it is necessary for an attachment to be raised while tests and/or adjustments are being performed, be sure the correct supports are in place. In the case of the bucket, it must be in the full DUMP position.
Move the machine to a location away from the travel of other machines.

Wear the seat belt, and be sure that other personnel are not near the machine when the engine is running and tests or adjustments are being performed.

Required Tools

Show/hide table




Illustration 1	g00993634
Tooling (A)

Show/hide table




Illustration 2	g00993685
Tooling (B) and (C)

Show/hide table




Illustration 3	g00993748
Tooling (D)

Show/hide table

Table 1
Required Tools
Tool	Item	Part Number	Description	Qty
A	A1	8T-0861	Pressure Gauge ( 60000 kPa (8702 psi))	1
	A2	171-1879	Adapter	1
	A3	187-3547	Fitting	1
	A4	187-3546	Coupler	2
	A5	177-7863	Hose As	1
B	B1	6V-4143	Coupler	2
	B2	6V-3989	Fitting	1
	B3	8T-0855	Pressure Gauge ( 4000 kPa (580 psi))	1
	B4	177-7860	Hose As	1
C	B1	6V-4143	Coupler	2
	B2	6V-3989	Fitting	1
	C3	8T-0861	Pressure Gauge ( 60000 kPa (8702 psi))	1
	B4	177-7860	Hose As	1
D	D1	6V-3965	Fitting As	1
D	D2	187-3546	Coupler	1

Quantities of Tooling

Use the "preferred quantities" of tooling in order to complete the stall test in the least amount of time. The stall test can be performed with the "minimum quantities". If you use the "minimum quantities", the test will take a longer amount of time.

Preferred Quantities

Tooling (A) ... 4

Tooling (B) ... 5

Tooling (C) ... 1

Tooling (D) ... 4

Minimum Quantities

Tooling (A) ... 1

Tooling (B) ... 2

Tooling (C) ... 1

Tooling (D) ... 1

Setup

Test the charge relief valve prior to performing the stall tests.

Show/hide table

NOTICE

Do not hold the transmission control lever in the full FORWARD or REVERSE position for more than 5 seconds at any one time. Return the lever to the NEUTRAL position for at least 10 seconds in order to prevent extreme overheating of the oil in the drive pumps.

Show/hide table

NOTICE

Do not stall the implements during hydraulic system warm-up. Stalling the implements causes oil to flow across the relief valve. This can damage the vane-type hydraulic pump when the system is cold. Before you allow the implements to stall, wait until the hydraulic system reaches operating temperature.

Perform the following steps in order to warm the hydraulic oil:

Note: Before you perform a transmission stall check, use calibration submode 20 in order to engage the parking brakes.

Move the governor switch to the HIGH IDLE position.

Move the speed/direction control lever to the full FORWARD position and hold for 5 seconds.

Move the speed/direction control lever to the PARK position and hold for 10 seconds.

Repeat Steps 2 and 3 for the full REVERSE position.

Repeat the above steps until the desired oil temperature is reached. The oil temperature must be 80° ± 8°C (176° ± 14°F) in order to perform the transmission stall tests.

Use the tooling in order to complete the "Data Sheet for the Stall Test" for each of the "Stall Conditions".

Show/hide table




Illustration 4	g00993740
Synchronization Manifold (E) Right REVERSE (F) Right FORWARD (G) Left REVERSE (H) Left FORWARD

Show/hide table




Illustration 5	g00993737

Connect up to four sets of tooling (A) to the pressure taps on the synchronization manifold. Use tooling (A) when the maximum drive pressure for a pressure tap is expected to be greater than 4000 kPa (580 psi). Use Illustration 4 to identify the pressure taps. Refer to Table 2 in order to determine the expected pressure.

Show/hide table




Illustration 6	g00993757

Use tooling (B) and (D) in place of tooling (A) when the maximum drive pressure is expected to be less than 4000 kPa (580 psi).

Show/hide table




Illustration 7	g00993723

Connect tooling (B) to the pressure tap for the charge pressure on the ECM manifold. The pressure tap is labelled with "CHG".

Show/hide table

Implement Pressure - Connect tooling (C) to this pressure tap. This is the pressure from the implement pump.

Use calibration submode 20 to determine the engine speed.

After you have completed the data sheet, compare your results with the "Analysis of the Stall Test" section.

Data Sheet

Note: Perform the calibration for both the engine OFF and the calibration for the engine ON before performing the stall tests.

Show/hide table

Table 2
Data Sheet for the Stall Test
Date Model PIN SMH
Stall Condition ⁽¹⁾		Engine Speed	Charge Pressure	Left FORWARD Drive Pressure	Right FORWARD Drive Pressure	Left REVERSE Drive Pressure	Right REVERSE Drive Pressure	Implement Pressure
HIGH IDLE No Load	Actual
HIGH IDLE No Load	Spec	2110 ± 50 RPM	2850 ± 100 kPa (415 ± 15 psi)	3000 kPa (435 psi) Maximum	3000 kPa (435 psi) Maximum	3000 kPa (435 psi) Maximum	3000 kPa (435 psi) Maximum	1600 kPa (230 psi) Maximum
Stall Implement Only RACKBACK Position	Actual
Stall Implement Only RACKBACK Position	Spec	2020 - 100 to - 150 RPM		3000 kPa (435 psi) Maximum	3000 kPa (435 psi) Maximum	3000 kPa (435 psi) Maximum	3000 kPa (435 psi) Maximum	21000 ± 340 kPa (3045 ± 50 psi)
Transmission Only FORWARD Direction	Actual
Transmission Only FORWARD Direction	Spec	1820 RPM Minimum	1800 kPa (260 psi) Minimum	44000 ± 2000 kPa (6400 ± 300 psi)	44000 ± 2000 kPa (6400 ± 300 psi)	3000 kPa (435 psi) Maximum	3000 kPa (435 psi) Maximum	1600 kPa (230 psi) Maximum
Transmission Only REVERSE Direction	Actual
Transmission Only REVERSE Direction	Spec	1820 RPM Minimum	1800 kPa (260 psi) Minimum	3000 kPa (435 psi) Maximum	3000 kPa (435 psi) Maximum	44000 ± 2000 kPa (6400 ± 300 psi)	44000 ± 2000 kPa (6400 ± 300 psi)	1600 kPa (230 psi) Maximum
Implement Rackback Transmission FORWARD	Actual
Implement Rackback Transmission FORWARD	Spec	1820 RPM Minimum	1800 kPa (260 psi) Minimum	35000 kPa (5100 psi) Minimum	35000 kPa (5100 psi) Minimum	3000 kPa (435 psi) Maximum	3000 kPa (435 psi) Maximum	21000 ± 340 kPa (3045 ± 50 psi)
Implement Rackback Transmission REVERSE	Actual
Implement Rackback Transmission REVERSE	Spec	1820 RPM Minimum	1800 kPa (260 psi) Minimum	3000 kPa (435 psi) Maximum	3000 kPa (435 psi) Maximum	35000 kPa (5100 psi) Minimum	35000 kPa (5100 psi) Minimum	21000 ± 340 kPa (3045 ± 50 psi)
Center Pedal Depressed FORWARD	Actual
Center Pedal Depressed FORWARD	Spec	1820 RPM Minimum		12000 kPa (1750 psi) ⁽²⁾	12000 kPa (1750 psi) ⁽²⁾	3000 kPa (435 psi) Maximum	3000 kPa (435 psi) Maximum	1600 kPa (230 psi) Maximum
Center Pedal Depressed REVERSE	Actual
Center Pedal Depressed REVERSE	Spec	1820 RPM Minimum		3000 kPa (435 psi) Maximum	3000 kPa (435 psi) Maximum	12000 kPa (1750 psi) ⁽²⁾	12000 kPa (1750 psi) ⁽²⁾	1600 kPa (230 psi) Maximum

Show/hide table

^( 1 )	The hydraulic oil must be at a temperature of 80° ± 8°C (176° ± 14°F) in order to perform the stall tests. See the following procedure in order to achieve the desired oil temperature for the stall tests.
^( 2 )	This is the minimum average of the left and right drive pressures in the same direction. The difference between the two pressures cannot exceed 40 percent of the average pressure.

Analysis of the Stall Tests:

Stall Test "A" (Implements)

Implement Pressure - Normal

Engine rpm - Low

If the preceding set of conditions exists, refer to Systems Operation/Testing and Adjusting for your machine's engine.

Stall Test "B" (Transmission)

The following set of conditions can occur in FORWARD and/or in REVERSE:

Charge pressure - Normal

Drive pressure - Low

Engine rpm - Normal

The preceding set of conditions can be a result of one of the following problems or a result of a combination of the following problems:

There is low drive relief pressure.

Note: Low drive relief pressure often occurs in only one direction or only on one side.

Reset the relief valve. If necessary, replace the relief valve.

The drive pressure is low in both directions on one side.
There is high internal cross port leakage within the drive pump or within the drive motor.

Note: This is determined after the efficiency of the drive pumps and after the efficiency of the drive motors have been tested.

Check the pumps and the motors. If necessary, repair the pumps and/or the motors.

Stall Test "C" (Transmission)

The following set of conditions can occur in both FORWARD and/or in REVERSE.

Charge pressure - Low

Drive pressure - Normal pressure, or low pressure

Engine rpm - Normal

The preceding set of conditions can be a result of one of the following problems or a result of a combination of the following problems:

The charge relief valve is not functioning properly.

Check the charge relief valve setting at HIGH IDLE and no load. If necessary, adjust the charge relief valve setting at HIGH IDLE and no load.

The charge pump is faulty.

Check the charge pump. If necessary, repair the charge pump.

There is high internal leakage of the case drain within the drive pumps or within the drive motors.

Note: This is determined after the efficiency of the drive pumps and after the efficiency of the drive motors have been tested.

Check the pumps and the motors. If necessary, repair the pumps and/or the motors.

Stall Test "D" (Transmission and Implements)

Charge pressure - Normal

Drive pressure - Low

Engine rpm - Normal

Implement pressure - Normal

The preceding set of conditions can be a result of one or more of the following problems:

The drive pressure is low in both directions on one side.
The engine power is low.

For additional information, refer to Systems Operation/Testing and Adjusting for your machine's engine.

Stall Test "E" (Transmission and Implements)

Charge pressure - Low

Drive pressure - Normal pressure, or low pressure

Engine rpm - Normal

Implement pressure - Normal

The preceding set of conditions can be a result of one of the following problems or a result of a combination of the following problems:

The drive pressure is low in one direction on one side.

Replace the relief valve.

The drive pressure is low in both directions on one side.
There is high internal leakage of the case drain within the drive pumps or within the drive motors.

Note: This is determined after the efficiency of the drive pumps and after the efficiency of the drive motors have been tested.

Check the pumps and the motors. If necessary, repair the pumps and/or the motors.