216 and 226 Skid Steer Loaders Machine Systems Caterpillar

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Sudden movement of the machine or release of oil under pressure can cause injury to persons on or near the machine. To prevent possible injury, perform the procedure that follows before testing and adjusting the power train.

Before any tests are performed, prepare the machine. Refer to Testing and Adjusting, "Machine Preparation". Before any tests are performed, visually inspect the complete hydraulic system for oil leaks and damaged parts. Refer to Testing and Adjusting, "Visual Inspection".

The tests for the hydraulic system should be done in the following order. In order for the hydrostatic system to function properly, each component in the system must be set to the correct specifications. Some components must be set prior to the testing of other components. A component that is not set properly will have an impact on other components in the system.

It is not advisable to bypass preceding tests. Do not perform a test before the tests that precede that test have been done. The preceding chart lists the equipment that is required to perform testing on the hydrostatic system. Equivalent tooling may be substituted.

Clearly mark all of the hoses and the corresponding pressure gauges, when the hoses are installed. The hoses and the pressure gauges will be used multiple times in the testing and adjusting procedures.

Throughout the entire testing procedure, MA pressure refers to the hydraulic oil pressure in the forward hydrostatic loop. MB pressure refers to the hydraulic oil pressure in the reverse hydrostatic loop.

Note: The oil in the hydraulic system must be at an operating temperature range of 50° ± 10°C (122° ± 18°F). In order to increase the oil temperature, start the engine and operate all the cylinders for at least five cycles. Also, drive the machine forward and drive the machine rearward.

Baseline for the Hydrostatic System

The test must be performed in order to establish a starting point for the hydrostatic system. After this test has been completed, two objectives will be established. You can test the machine and you can establish a baseline for the remaining tests.

Clearly mark all of the hoses and the corresponding pressure gauges, when the hoses are installed.

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Illustration 1	g00560554
Use cribbing to elevate the machine.

1. Use cribbing to elevate the machine. The wheels must not touch the ground.

2. Release the hydraulic system pressure. Refer to Testing and Adjusting, "Hydraulic System Pressure - Release" for the proper procedure.

3. Raise the cab. Refer to Operation and Maintenance Manual, "Cab Support Operation" for the proper procedure.

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Illustration 2	g00727151
(1) PS1 charge pressure tap

4. Install one 8T-0855 Pressure Gauge to the charge pressure tap (1) with a 6V-3014 Hose .

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Illustration 3	g00727164
(2) PS2 speed sensing pressure tap

5. Install one 8T-0855 Pressure Gauge to the speed sensing pressure tap (2) with a 6V-3014 Hose .

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Illustration 4	g00726807
The location of plug (3) in the case drain port .

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Illustration 5	g00726808
The location of pressure tap (4) for the case drain.

6. Install a 3J-1907 O-Ring Seal (F) on each 6V-3965 Valved Nipple Assembly (G). Install a 6V-3965 Valved Nipple Assembly (G) into each 5P-1404 Adapter (H). Remove two plugs (3) from the case drain ports on each of the piston pumps. Install a 5P-1404 Adapter (H) into each case drain port on the piston pump.

7. Install one 8T-0853 Pressure Gauge to each pressure tap (4) for the first section of the piston pump. Install the remaining hose to pressure tap (4) on the second section of the piston pump.

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Illustration 6	g00561328
The placing of the multitach for engine speed.

8. Install a 6V-3121 Multitach (K), or install a 9U-7400 Multitach Tool Group (K) in order to measure engine rpm. Read the rpm from the reflective tape that is on the pulley for the engine crankcase.

9. Install a 6V-3121 Multitach, or install a 9U-7400 Multitach Tool Group in order to measure the fan speed. Read the rpm from the reflective tape that is on the fan blade.

10. Lower the cab. Route the test hoses so that the cab does not rest on any of the hoses.

11. Start the engine and run the engine at low idle.

    If the engine speed for low idle is incorrect, perform the following adjustments to the cable assembly of the 142-9261 Governor Control :

    • Set the throttle to the HIGH IDLE position.

    • Install the cable assembly to the engine so the cable nuts can be positioned and tightened in order to set the throttle's bracket. The bracket must make contact with the high idle stop.

    • Move the throttle to the LOW IDLE position.

    • Adjust the 6V-7357 Bolt until the low idle stop remains in slight contact with the bracket.

    • Tighten the 5C-2890 Nut in order to lock the bolt in place.

    Note: Low idle and high idle have been preset at the factory. the setting of the low idle and the high idle on these engines should not be adjusted. Adjusting the setting can void the warranties on the fuel injection pump and the engine. Adjusting the setting can invalidate the standards for emissions. Adjustment of the low idle and the high idle should be made only by trained personnel. The low idle and high idle for most engine applications is given in the Systems Operation, "Engine Design". Some engine applications may have a different low idle and high idle.

    Note: Verify the engine rpm for the low idle and the high idle by referring to the Technical Marketing Information (TMI) or to the Fuel Setting and Related Information Fiche.

12. Record the following items: the charge pressure, the speed sensing pressure, the pressures for the case drain ports on the two piston pumps, the engine RPM and the fan RPM.

13. Increase the engine speed to high idle.

    If the engine speed for high idle is incorrect, perform the following adjustments to the cable assembly of the 142-9261 Governor Control :

    • Set the throttle to the HIGH IDLE position.

    • Install the cable assembly to the engine so the cable nuts can be positioned and tightened in order to set the throttle's bracket. The bracket must make contact with the high idle stop.

    • Move the throttle to the LOW IDLE position.

    • Adjust the 6V-7357 Bolt until the low idle stop remains in slight contact with the throttle's bracket.

    • Tighten the 5C-2890 Nut in order to lock the bolt in place.

    Note: High idle must be checked under conditions with no load on the engine. Measure the high idle after the engine has reached normal operating temperature.

    Note: Low idle and high idle have been preset at the factory. The setting of the low idle and the high idle on these engines should not be adjusted. Adjusting the setting can void the warranties on the fuel injection pump and the engine. Adjusting the setting can invalidate the standards for emissions. Adjustment of the low idle and the high idle should be made only by trained personnel. The low idle and high idle for most engine applications is given in the Systems Operation, "Engine Design". some engine applications may have a different low idle and high idle.

    Note: Verify the engine rpm for the low idle and the high idle with either the Technical Marketing Information (TMI) or the Fuel Setting and Related Information Fiche.

14. Record the following items: the charge pressure, the speed sensing pressure, the pressures for the case drain ports on the two piston pumps, the engine RPM and the fan RPM.
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    Table 2

    BASELINE FOR THE HYDROSTATIC SYSTEM
    Test	Low Idle	High Idle
    Engine Speed	1000 ± 50 rpm	2820 ± 50 rpm
    Charge Pressure	2900 ± 100 kPa (420 ± 15 psi)	3300 ± 200 kPa (480 ± 30 psi)
    Speed Sensing Pressure	1100 ± 100 kPa (160 ± 15 psi)	2200 ± 100 kPa (320 ± 15 psi)
    Pressure for the Pump Case	100 ± 50 kPa (15 ± 7 psi)	200 ± 100 kPa (30 ± 15 psi)
    Fan Speed	1225 ± 25 rpm	2600 ± 50 rpm

If the charge pressure is too low or too high at high idle, perform the following checks:

• Check the gear pump.

• The possibility exists of a large internal leak in the following components: brakes, piston pump, piston motors, pilot valves and interlock manifold. Refer to Table 3 in order to troubleshoot.

• Replace the charge relief valve and recheck the pressure.

• There may be a restriction in the tube assembly between the two sections of the piston pump.

• The fan motor may have failed.

If the charge pressure is too low at low idle, perform the following checks:

• The possibility exists of a large internal leak in the following components: brakes, piston pump, piston motors, pilot valves and interlock manifold. Refer to Table 3 in order to troubleshoot.

If the case pressure of the piston pump is high, perform the following checks:

• Check for a restriction of the lines.

• Check the oil temperature. Make sure that the operating temperature of the oil is correct. Check the viscosity of the oil.

• There may be an internal leak.

• The possibility exists of a worn piston pump.

If the case pressure for the piston pump is low, perform the following checks:

• The lip seal of the piston pump is blown. Check for leaking oil.

If the speed sensing pressure is low at low idle, perform the following adjustment:

• Turn the adjustment screw on the speed sensing valve counterclockwise.

If the speed sensing pressure is high at low idle, perform the following adjustment:

• Turn the adjustment screw on the speed sensing valve clockwise.

If the speed sensing pressure is low at high idle, perform the following adjustments:

• Turn the adjustment screw on the speed sensing valve counterclockwise.

Note: Do not disconnect the lines or the gauges if adjustments need to be performed. The gauges will be used in order to check the pressures for the required tests and adjustments. Leave the 6V-3121 Multitach or the 9U-7400 Multitach Tool Group connected in order to measure the engine rpm for the tests that follow. Refer to Testing and Adjusting, "Hydrostatic System - Test and Adjust" for the required tests and adjustments.

Start to Move Test

Perform the start to move test in order to make sure that the piston pump is synchronized. If the pump is not synchronized, the machine could drift or the machine could move in the NEUTRAL position. If the pump is not synchronized, the wheels on one side of the machine could start to move before the wheels on the other side of the machine start to move.

Note: If the left wheels and the right wheels start to move at the same time, this test is not required.

Note: If the drive chains are not adjusted correctly, the left wheels and the right wheels may not start to move at the same time.

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Illustration 7	g00560554

1. Use cribbing in order to elevate the machine. The wheels must not touch the ground.

2. Raise the cab. Refer to Operation and Maintenance Manual, "Cab Support Operation" for the proper procedure.

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Illustration 8	g00726882
(1) Neutral adjusting bolt for Pump 1 (2) Neutral adjusting bolt for Pump 2 (3) The MA Ports (4) The MB Ports (D) Pump 1 (E) Pump 2

Note: Perform the test on pump 1 of the pump group first. Pump 1 powers the piston motor which is on the left side of the machine.

3. Install one 8T-0857 Pressure Gauge to the MA port (3) on pump 1 with a 6V-3014 Hose Assembly. Install one 8T-0857 Pressure Gauge (3) to the MB port (4) on pump 1 with a 6V-3014 Hose Assembly. Refer to Illustration 8.

4. Place the two gauges in an easily visible position.

5. Lower the cab. Route the test hoses so that the cab does not rest on any of the hoses.

6. Fasten the seat belt and lower the armrest.

7. Start the engine and run the engine at low idle.

8. Raise the cab.

9. Loosen the locknut for the neutral adjusting bolt. Do not use an impact socket.

10. Turn neutral adjusting bolt (1) clockwise. Mark the location of the neutral adjusting bolt when the MA pressure begins to increase.

11. Turn neutral adjusting bolt (1) counterclockwise. Mark the location of the neutral adjusting bolt when the MB pressure begins to increase.

12. Turn the neutral adjusting bolt (1) midway between the two marks.

13. Hold the neutral adjusting bolt (1) in position as you tighten the locknut to 44 ± 2 N·m (32 ± 1 lb ft).

14. Repeat this test on Pump 2. Pump 2 powers the piston motor which is on the right side of the machine.

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Illustration 9	g00726885
(2) Neutral Adjusting Bolt (3) The MA Port (4) The MB Port (5) 142-8739 Tube (D) Pump 1 (E) Pump 2

15. Loosen the neutral adjusting bolt (2) on pump 2 (E) .

    Note: For machines with serial numbers (S/N: 4NZ1-505) and (S/N: 5FZ1-688), you must perform Step 15.a through Step 15.m in order to loosen the locknut for neutral adjusting bolt (2) .

    1. Lower the cab.

    2. Stop the engine.

    3. Raise the cab.

    4. Loosen the end of the 142-8739 Tube (5) that is toward the rear of the machine. Refer to Illustration 9.

    5. Disconnect the end of tube (5) that is toward the front of the machine.

    6. Plug tube (5) with a 9S-8927 Plug .

    7. Cap the elbow with an 8S-4950 Cap .

    8. Rotate tube (5) counterclockwise in order to access the locknut for neutral adjusting bolt (2) .

    9. Loosen the locknut for neutral adjusting bolt (2) .

    10. Remove the plug from tube (5) .

    11. Remove the cap from the elbow.

    12. Reconnect tube (5) to the rear pump section. Tighten the fitting to a torque of 48 ± 5 N·m (35 ± 4 lb ft).

    13. Tighten the fitting on tube (5) that is toward the rear of the machine. Tighten this fitting to a torque of 27 ± 3 N·m (20 ± 2 lb ft).

16. Lower the cab.

17. Start the engine and run the engine at low idle.

18. Raise the cab.

19. Turn the neutral adjusting bolt (2) clockwise. Mark the location of the neutral adjusting bolt when the MA pressure begins to increase.

20. Turn the neutral adjusting bolt (2) counterclockwise. Mark the location of the neutral adjusting bolt when the MB pressure begins to increase.

21. Turn the neutral adjusting bolt (2) midway between the two marks.

22. Hold the neutral adjusting bolt (2) in position. Tighten the locknut to 44 ± 2 N·m (32 ± 1 lb ft).

    Note: For machines with serial numbers (S/N: 4NZ1-505) and (S/N: 5FZ1-688), you must perform Step 22.a through Step 22.m in order to tighten the locknut for the neutral adjusting bolt (2) .

    1. Lower the cab.

    2. Stop the engine.

    3. Raise the cab.

    4. Loosen the end of the 142-8739 Tube (5) that is toward the rear of the machine. Refer to Illustration 9.

    5. Disconnect the end of tube (5) that is toward the front of the machine.

    6. Plug tube (5) with a 9S-8927 Plug .

    7. Cap the elbow with a 8S-4950 Cap .

    8. Rotate tube (5) counterclockwise in order to access the locknut for the neutral adjusting bolt (2) .

    9. Hold the neutral adjusting bolt (2) in position. Tighten the locknut to 44 ± 2 N·m (32 ± 1 lb ft).

    10. Remove the plug from the tube (5) .

    11. Remove the cap from the elbow.

    12. Reconnect tube (5) to Pump 2. Tighten the fitting to a torque of 48 ± 5 N·m (35 ± 4 lb ft).

    13. Tighten the fitting on tube (5) that is toward the rear of the machine. Tighten this fitting to a torque of 27 ± 3 N·m (20 ± 2 lb ft).

23. Lower the cab.

24. Fasten the seat belt and lower the armrest.

25. Start the engine. Run the engine at low idle.

    Note: In the next step, the wheels will rotate. Make sure that all hoses are out of the way of the rotating wheels.

26. Move the pilot operated hydraulic control ( hydrostatic) slowly forward. Check that the left wheels and the right wheels start to move at the same time.

27. If the wheels do not start to move at the same time, then repeat this test.

28. If the wheels start to move at the same time, then remove the hoses from the MA and the MB pressure taps.

Maximum Runout

This test is used to determine if the engine and the machine speeds are correct for the maximum travel speed.

1. The hose assemblies and gauges for charge pressure and for speed sensing pressure should still be in place. If the units are not in place, reinstall the units.

2. Reinstall the hose assemblies for the MA ports and the MB ports.

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Illustration 10	g00560554

3. The machine should still be blocked up. The wheels must not touch the ground.

4. The 6V-3121 Multitach or the 9U-7400 Multitach should still be installed on the machine. If the unit is not installed, reinstall the unit.

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Illustration 11	g00726910

5. One wheel on each side of the machine must be checked for proper speed. Apply four pieces of reflective tape to each wheel at 90 degree intervals. Use a 1U-6602 Phototach to record the rpm of the wheels.

6. Start the machine and run the machine at high idle. Disengage the parking brake. Push the pilot operated hydraulic control ( hydrostatic) in the FORWARD direction. Record the rpm of a wheel on each side of the machine and divide that number by four.

7. Record the MA pressures, the speed sensing pressures, the charge pressure and the wheel rpm.
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   Table 5

   MAXIMUM RUNOUT
   Test	Specification
   Engine Speed	2820 ± 50 RPM
   Speed Sensing Pressure	2200 ± 100 kPa (320 ± 15 psi)
   Charge Pressure	3300 ± 200 kPa (480 ± 30 psi)
   MA Pressure Front Pump	6000 ± 500 kPa (800 ± 85 psi)
   MA Pressure Rear Pump	6000 ± 500 kPa (800 ± 85 psi)
   Wheel RPM	80 ± 8 rpm (1)

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   ( 1 )

   The wheel speeds must be within 2 RPM of each other.

Perform the following check if the pump signal pressure is not to the correct specification.

• The speed sensing valve may be misadjusted.

Perform the following check if the MA pressure and the MB pressure is high in the FORWARD direction and in the REVERSE direction.

• The axle may have a problem.

• The brake may not be released.

• The chain drive may be out of adjustment.

Stall Test

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Sudden movement of the machine or release of oil under pressure can cause injury to persons on or near the machine. To prevent possible injury, perform the procedure that follows before testing and adjusting the power train.

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Personal injury can result from hydraulic oil pressure and hot oil. Hydraulic oil pressure can remain in the hydraulic system after the engine has been stopped. Serious injury can be caused if this pressure is not released before any service is done on the hydraulic system. Make sure all of the attachments have been lowered, oil is cool before removing any components or lines. Remove the oil filler cap only when the engine is stopped, and the filler cap is cool enough to touch with your bare hand.

The test can be used in order to identify low power problems with the engine. The test is also used to identify the crossover relief valves that may be malfunctioning.

1. Raise the cab. Refer to Operations and Maintenance Manual, "Cab Support Operation" for the correct procedure.

   Note: The machine should still be up on the cribbing from the previous tests.

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Illustration 12	g00726915

2. The brakes need to be engaged for this test. Disconnect the electrical connection (1) for brake solenoid (2) on the interlock manifold. It should not be possible to drive through the brakes.

3. The 6V-3121 Multitach or the 9U-7400 Multitach Tool Group should still be installed on the machine. If a unit is not installed, reinstall the unit.

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Illustration 13	g00727166
(A) Pressure tap MA for pump 2 (B) Pressure tap MB for pump 2

4. The two gauges should still be attached to pressure ports (A) and (B) on pump 2. Disconnect the gauge from port (B) .

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Illustration 14	g00727168
(A) Pressure tap MA for pump 1 (B) Pressure tap MB for pump 1

5. Connect the gauge to port (A) on pump 1.

6. Lower the cab.

7. Fasten the seat belt and lower the armrest.

8. Start the engine and run the engine at low idle.

9. Slowly increase the engine speed to high idle.

10. Push the pilot operated hydraulic control ( hydrostatic) to the FORWARD position until the engine stalls.

Note: The wheels should not spin. If the wheels spin, refer to the Testing and Adjusting, "Brake Test".

11. Record the engine rpm and record the MA pressures for the two drive loops.

If the engine lug is high, perform the following check:

• The piston pump may have an internal leak, or the piston motor may have an internal leak.

• The engine power may be low.

• The speed sensing valve may be set too high.

Perform the following check if the engine lug is low for the stall of the hydrostatic system:

• The speed sensing valve may be set too low.

If the MA pressure is low and the engine lug is high, perform the following checks:

• The crossover relief valve is set incorrectly. Switch the two crossover relief valves. If the problem is not corrected then replace the piston pump.

Double Stall Test

This test will determine if the engine performance is low.

Note: The brake solenoid should still be disconnected and the machine should still be up on the cribbing. The 6V-3121 Multitach or the 9U-7400 Multitach Tool Group should still be installed on the machine. If a unit is not installed, reinstall the unit.

1. Start the engine.

2. Increase the engine speed to high idle.

Note: Do not stall the machine for more than 15 seconds. Damage to the machine could result.

3. Push the pilot operated hydraulic control ( hydrostatic) in the FORWARD direction.

4. At the same time, push the pilot operated hydraulic control ( work tool) to the TILT BACK position.

5. Record the MA pressures and the engine rpm.

If the engine rpm is not to the correct specification, perform the following checks:

• The engine power is low. Check the throttle, injectors, and fuel pressure.

• Check for a parasitic load.

• Check the speed sensing valve. Adjust the speed sensing valve if the setting is not set to specifications.

• Check the main relief valve. Adjust the main relief valve if the setting is not set to specifications.

Perform the following check if the engine lug is satisfactory for the stall of the hydrostatic system, but the engine lug is low for the stall of the hydraulic system:

• The main relief valve may be set too low.

• There may be an internal leak in the hydraulic system.

Perform the following check if the engine lug is satisfactory for the stall of the hydrostatic system, but the engine lug is high for the stall of the hydraulic system.

• The engine may have low power.

• The main relief valve may be set too high.

Perform the following check if the engine lug is satisfactory for the stall of the hydraulic system, but the engine lug is high for the stall of the hydrostatic system.

• The piston motor may have an internal leak.

• The piston pump may have an internal leak.

• The crossover relief valve may be set too low or the crossover relief valve may be damaged.

• The speed sensing valve may be set too high.

Maximum Displacement Stop Test

This test is applicable for machines with serial numbers (S/N: 4NZ562-UP) and (S/N: 5FZ1717-UP).

This test will determine if the displacement stops are adjusted correctly in the piston pumps. The two displacement stops determine the maximum stroke of the swashplate in each of the piston pumps in the forward direction.

Note: Before you adjust the displacement stops, the right side wheels and left side wheels of the machine must begin to move at the same time. Refer to Testing and Adjusting, "Start to Move Test".

Note: If the machine drifts to the same side in both forward and reverse, check the chain tension on both sides of the machine before you proceed with the following test.

1. Move the machine to a testing location that is flat, level, and 30.5 m (100 ft) long. Allow enough space on each side of the center line for any machine drift that could exceed 3 m (10 ft).

2. Inflate all four tires to the same air pressure.

3. Start the test outside the test area. The machine must enter the testing location in a straight line travel and the machine must be travelling at full speed. The engine must be set to high idle and the pilot operated hydraulic control ( hydrostatic) must be positioned fully forward.

4. Measure the amount of drift and record the direction of drift.

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Illustration 15	g00695720
Turn the adjustment screw (A) clockwise when the machine drifts to the left. Turn the rear adjustment screw (B) clockwise when the machine drifts to the right.

5. If the machine drifts over 3 m (10 ft) to the left, you must turn the adjustment screw (A) in 1/8 increments of a turn clockwise. You must loosen the adjustment screw locknut that is on screw (A) before you make any adjustments. Refer to the illustration for the location of the displacement adjustment screw.

   If the machine drifts over 3 m (10 ft) to the right, you must turn the adjustment screw (B) in 1/8 increments of a turn clockwise. You must loosen the adjustment screw locknut that is on screw (B) before you make any adjustments. Refer to the illustration for the location of the displacement adjustment screw.

   Note: After every adjustment to an adjustment screw, repeat the drift test until the machine drift is acceptable.

6. After you finish adjusting an adjustment screw, tighten the locknut to a torque of 22 N·m (16 lb ft). Cover the maximum displacement adjustment screws with 6E-5060 Caps .

Brake Test

This test will determine if the brakes are functioning correctly. This test will check the interlock manifold and the piston motor.

1. Raise the cab. Refer to Operation and Maintenance Manual, "Cab Support Operation".

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Illustration 16	g00726915

2. Disconnect electrical connection (1) for brake solenoid (2) .

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Illustration 17	g00726916

3. Install a 7X-2444 Tee (3) and a 6V-3965 Valved Nipple Assembly (4) in the hydraulic line that runs from the interlock manifold to the piston motors.

4. Install a 8T-0855 Pressure Gauge to the diagnostic tee with a 6V-3014 Hose .

5. Lower the cab. Make sure that the hydraulic line is not pinched.

6. Fasten the seat belt. Lower the armrest.

7. Start the machine. The pressure gauge should read 0. If the gauge does not read 0, inspect the brake solenoid and the voltage for the brake solenoid.

8. Stop the machine. Raise the cab and reconnect the brake solenoid.

9. Lower the cab. Fasten the seat belt. Lower the armrest and start the machine.

10. Disengage the parking brake by pressing the parking brake switch. The pressure on the gauge should be 2900 ± 100 kPa (420 ± 14 psi).

11. If the pressure is not correct inspect the following items: the brake solenoid, the voltage for the brake solenoid and the brake seal inside the piston motor.

12. If the brake solenoid is not functioning correctly, replace the solenoid. Refer to Disassembly and Assembly, RENR2862, "Interlock Manifold - Disassembly" for the proper procedure.

13. When the test is completed, raise the cab, and disconnect all gauges and hoses. Lower the cab and bolt the cab in place. Refer to Operation and Maintenance Manual, "Cab Support Operation".