Testing And Adjusting

Usage:

Important Information

Reference: For Specifications with illustrations, make reference to SENR6773, 914G Wheel Loader and IT14G Integrated Toolcarrier, Hydraulic Systems Specifications. If the Specifications in SENR6773 are not the same as in the Systems Operation and the Testing and Adjusting, look at the printing date on the cover of each book. Use the Specification in the book with the latest date.

Show/hide table

Personal injury or death can result from improperly checking for a leak.

Always use a board or cardboard when checking for a leak. Escaping fluid under pressure, even a pinhole size leak, can penetrate body tissue, causing serious injury, and possible death. If fluid is injected into your skin, it must be treated immediately by a doctor familiar with this type of injury.

Show/hide table

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 hydraulic system.

1. Move the machine to a smooth horizontal location. Move away from working machines and personnel. Lower the bucket to the ground. Stop the engine.

2. Permit only one operator on the machine. Keep all other personnel either away from the machine or in view of the operator.

3. Engage the parking brake. Put blocks in front of and behind the wheels.

4. When the bucket is raised for tests or adjustments, make sure that the bucket has correct support and that it is fully in the DUMP position. The lift circuit has high oil pressure when the lift arms raise the front of the machine.

Do not stop the engine with the front of the machine off of the ground, unless a system test requires it. Lower machine to the ground and stop the engine.

5. Install the steering frame lock link so the machine can not turn.

6. Move the hydraulic control levers to all positions to release the pressure in the hydraulic system. Place the tilt control lever in the FLOAT position. Place the lift control lever in the HOLD position.

7. Carefully loosen the fill cap on the hydraulic tank to release the pressure in the tank.

8. Make sure all hydraulic pressure is released before any fitting, hose or component is loosened, tightened, removed or adjusted.

9. Tighten the fill cap on the hydraulic tank.

10. The pressure in the system has now been released and lines or components can be removed.

During a diagnosis of the hydraulic system, remember that correct oil flow and pressure are necessary for correct operation. The output of the pump increases with an increase in engine speed and decreases when engine speed is decreased. Oil pressure is caused by resistance to the flow of oil.

Visual Checks

Show/hide table

Make reference to WARNING on first page of Hydraulic System Testing And Adjusting section.

The 4C4890 and 8T5320 Hydraulic Test Groups, or 1U5481 Pressure Gauge Group are used to make the pressure test of the hydraulic system. Before any tests are made, visually inspect the complete hydraulic system for leakage of oil and for parts that have damage. For some of the tests, a magnet and a measuring rule (either for inches or millimeters) are usable tools.

Visual checks and measurements are the first step when troubleshooting a possible problem. Then perform the Operation Checks and last the Instrument Tests. Lower the bucket to the ground and stop the engine. To remove the hydraulic tank fill cap, slowly turn the fill cap until it is loose. If oil comes out, allow the tank pressure to lower before the fill cap is removed. Make the following inspections:

1. Check the hydraulic tank oil level. Slowly turn the fill cap until it is loose. If oil comes out, allow the tank pressure to lower before the fill cap is removed.

2. Look for air in the oil. Perform this immediately after the machine is stopped. Use a clear bottle or container to collect a sample of the oil. Look for air bubbles in the oil that is in the bottle.

3. Remove the filter elements and look for particles removed from the oil by the filter element. A magnet will separate ferrous particles from nonferrous particles (piston rings, O-ring seals, etc.).

4. Check all oil lines and connections for damage or leaks.

5. Inspect control linkage for bent, broken or damaged components.

Performance Tests

The hydraulic circuits are connected in an interrupted series arrangement. The hydraulic pump and relief valve for main pressure is common to the circuits. The auxiliary/and tilt circuits have make-up and check valves in both the head and rod ends to prevent cylinder drift during valve spool movement. The lift circuit has a make-up valve only on the rod end.

The relief valves in the auxiliary/coupler and tilt circuit give protection to the components from pressures in the circuits when the control valves are in the HOLD position.

1. The pressure of the oil to open the relief valves for the main system and the relief valves for the auxiliary/coupler and tilt circuits must be to specification. Relief valve pressures that are too low will cause a decrease in the lift and the dig characteristics of the machine. Pressures that are too high will cause a decrease in the lift of hoses and components.

2. Drift rates in the lift and tilt circuits: Circuit drift is caused by a leakage past cylinder pistons, O-ring seals in the control valves, check valves or makeup valves that do not seat correctly or poor adjustment or fit in the control valves.

3. Cycle times in the lift and tilt circuits: Cycle times that are longer than those shown on the charts in section Lift And Tilt Circuit Speeds are the result of leakage, pump wear and/or pump speed (rpm).

If the basic tests give an indication of circuit leakage, install a Flow Meter and perform a system test. This procedure will find the source of the leakage.

Problem 1: Pump makes noise, the cylinder rods do not move smoothly and there are air bubbles in the oil.

Probable Cause:

1. The viscosity of the hydraulic oil is incorrect.

2. The relief valve opens at low oil pressure.

3. Loose connection of the oil line on the inlet side of the pump.

4. The pump has too much wear.

Problem 2: The temperature of the oil is too hot.

Probable Cause:

1. The viscosity of the hydraulic oil is incorrect.

2. The relief valve opens at low oil pressure.

3. The pump has too much wear.

4. There is a restriction in an oil passage.

5. The load of the system is too high.

6. Low oil level.

7. Air in the hydraulic oil.

NOTE: If the problem is because of air in the oil, it must be corrected before the system will operate at normal temperatures. There are two things that cause air in the oil (aeration).

a. Return oil to the tank flows in above the level of the oil in the tank.

b. Air leaks in the oil suction line between the pump and the tank.

Problem 3: The output of the pump is low.

Probable Cause:

1. Low oil level.

2. The viscosity of the hydraulic oil is incorrect.

3. The pump has too much wear.

Problem 4: The pressure of the oil is low.

Probable Cause:

1. The relief valve opens at low oil pressure.

2. The pump has too much wear.

3. The failure of an o-ring seal in the system.

4. The control valve and valve spool have a large amount of wear.

Problem 5: Attachment moves with control lever in HOLD position.

Probable Cause:

1. The control valve and valve spool have a large amount of wear.

2. A piston seal in a cylinder has a large amount of wear.

3. A leak in a connection between the control valve and the cylinders.

4. A leak check valve not closing because of dirt or a worn seat.

Problem 6: Attachment droops when control lever is moved from HOLD to LIFT.

Probable Cause:

Load check valve not closing.

a. Weak or broken spring.

b. Dirt or debris in valve.

Hydraulic Oil Temperature Too High

When the temperature of the hydraulic oil rises above 99°C (210°F), polyurethane seals in the system start to fail. High oil temperature causes seal failure to become more rapid. There are many reasons why the temperature of the oil will get this hot.

1. Hydraulic pump is badly worn.

2. Heavy hydraulic loads that cause the relief valve to open.

3. The setting on the relief valve is too low.

4. Too many restrictions in the system.

5. Low oil level.

6. High pressure oil leak in one or more circuits.

7. Very dirty oil.

8. Air in the hydraulic oil.

NOTE: If the problem is because of air in the oil, it must be corrected before the system will operate at normal temperatures. There are two things that cause air in the oil (aeration).

a. Return oil to the tank rises above the level of the oil in the tank.

b. Air leaks in the oil suction line between the pump and the tank.

Pump Efficiency Check

NOTE: For more information on the hydraulic pump, see SENR6773, Hydraulic System Specifications.

For any pump test at a given rpm, the pump flow at 690 kPa (100 psi) will be larger than the pump flow at 6900 kPa (1000 psi). The difference between the pump flow of the two operating pressures is the flow loss.

Method of finding flow loss:

Flow loss when expressed as a percent of pump flow is used as a measure of pump performance.

Example of finding percent of flow loss:

If the percent of flow loss is more than 10%, pump performance is not good enough.

^*Numbers in examples are for illustration and are not values for any specific pump or pump condition. See Specifications for pump flow of a new pump at 690 kPa (100 psi) and 6900 kPa (1000 psi).

Machine Test

Install a Flow Meter. For Formula I, measure pump flow at 690 kPa (100 psi) and at 6900 kPa (1000 psi) with the engine at high idle rpm.

Bench Test

If the test bench can be run at 6900 kPa (1000 psi) and at full pump rpm, find the percent of flow loss using Formula I.

If the test bench cannot be run at 6900 kPa (1000 psi) and at full pump rpm, run the pump shaft at 1000 rpm. Measure the pump flow at 690 kPa (100 psi) and at 6900 kPa (1000 psi). Use these values in the top part of Formula II. For the bottom part of the formula, run the pump shaft at 2000 rpm. Measure the pump flow at 690 kPa (100 psi).

Operation Checks

Show/hide table

Make reference to WARNING on first page of Hydraulic System Testing And Adjusting section.

The operation checks can be used to find leakage in the system. They can also be used to find a bad valve or pump. The speed of rod movement when the cylinders move can be used to check the condition of the cylinders and the pump.

Lift, lower, dump and tilt back the bucket/attachment several times.

1. Watch the cylinders as they are extended and retracted. Movement must be smooth and regular.

2. Listen for noise from the pump.

3. Listen for the sound of the relief valves. They must not open except when the cylinders are fully extended or retracted, when the bucket/attachment is empty.

4. Watch the operation of the bucket/attachment positioner and lift kickouts.

The lift control lever has detents in the RAISE and FLOAT positions.

The tilt control lever has a detent in the TILT BACK position (only when the bucket/attachment is between full dump and the bucket angle to dig).

Lift And Tilt Cylinder Drift Tests

The oil in the system must be SAE 10 and at a recommended temperature of 38 C° (100.4 F°) minimum to 65° C (150° F) maximum to get accurate tests results. All speed tests are made with the engine at high idle.

The drift rates will change with different conditions of the hydraulic components as well as with the operation, the type of bucket/attachment (empty or loaded), hydraulic oil temperature, etc.

The values shown are for an empty bucket/attachment. Before measuring drift on the cylinder rod, the cylinders must be extended at least five times. Check the oil temperature.

To check the lift circuit, lift the bucket to maximum height and move the control lever to the HOLD position. Place the hydraulic lock lever in the OFF position. Measure the distance (and check the time) that the cylinders retract, with the chart.

NOTE: The drift distances in the charts are for new machines

To check the tilt circuit, lift the bucket/attachment to maximum height, and move the lift control lever to the HOLD position. Activate the tilt circuit until the bucket/attachment is at the angle to dig/load (almost level) and move the tilt control lever to the HOLD position. Place the hydraulic lock lever in the OFF position. Measure the distance and check the time that the cylinder retracts, with the chart.

If the cylinder drift is too much:

1. Check the makeup valves in the lift and tilt control valve.

2. Check the condition of the valve spools in the lift and tilt main control valves.

3. Check the piston seals in the cylinders.

Lift And Tilt Cylinder Speed Tests

Start and run the engine at high idle rpm. Lift and lower the lift arms again and again to get an increase in the temperature of the hydraulic oil.

The oil in the system must be SAE 10 and at a temperature of 38 C° (100.4 F°) minimum to 65° C (150° F) maximum to get accurate test results. All speed tests are made with the engine at high idle. If the machine is equipped with optional ride control system, place the ride control switch in the OFF position. The speeds in the following chart are those of machine equipped with a general purpose bucket.

System speeds that are similar to those given in the charts give an indication that the circuits under test are operating normally. Separate tests must be made for the relief valves to be sure that they are working at their correct rating.

If the travel times are not correct:

1. Check the pump efficiency.

2. Check the setting of the relief valves.

3. Check the makeup valves in the lift and tilt control valves.

4. Check the valve spools in the lift and tilt control valves.

5. Check the piston seals in the cylinders.

Pilot System Pressure Test

NOTE: The implement pilot oil system is supplied oil from the propulsion system charge pump. For troubleshooting and testing and adjusting information refer to SENR6766, 914G Wheel Loader and IT14G Integrated Toolcarrier, Power Train System Operation, Testing And Adjusting.

Relief Valves - 914G

Show/hide table

Make reference to WARNING on first page of Loader Hydraulic System Testing And Adjusting section.

1. Lower the bucket so it is on the ground and can not be tilted. Remove the cover that is over the control valve, from the front of the loader frame to gain access to main and line relief valves.

2. Increase the temperature of the oil up to normal operating temperature.

Main Relief Valve

Show/hide table

Make reference to WARNING on first page of Loader Hydraulic System Testing And Adjusting section.

Main Control Valve
(1) Pressure tap. (2) Main relief valve.

Main Relief Valve
(3) Cap. (4) Locknut. (5) Adjusting screw.

1. Lower the bucket so it is on the ground and can not be tilted. To gain access to the main relief valve, remove the cover from the front of the loader frame. Release hydraulic system pressure.

2. Carefully loosen the tank fill cap to release any pressure in the tank. Tighten the cap.

3. Install a connector, hose and pressure gauge at pressure tap (1).

4. Start the engine.

5. Raise the bucket off the ground. Tilt back the bucket until the tilt cylinder rod is fully retracted.

6. Increase engine rpm to high idle, look at the test gauge and move the tilt control lever to the TILT BACK position.

7. The pressure setting of main relief valve (2) should be 24 150 ± 350 kPa (3500 ± 50 psi).

NOTE: Do not keep the control lever in the TILT BACK position, at the relief valve setting, more than 5 seconds.

8. If the opening pressure of the relief valve is not to specification it will be necessary to adjust the valve.

9. Stop the engine.

10. Remove cap (3). Loosen locknut (4) and turn screw (5) clockwise for an increase or counterclockwise for a decrease in the pressure setting of the relief valve.

11. After screw (5) is turned for an adjustment, tighten locknut (4).

12. Start the engine. Repeat steps 5, 6 and 7.

13. If pressure is correct, lower the bucket to the ground and stop the engine.

14. If pressure is not correct, repeat steps 10, 11, 12 and 13.

15. When pressure setting is correct, stop the engine. Remove the test equipment.

Tilt Cylinder Rod End Relief Valve

Show/hide table

Make reference to WARNING on first page of Loader Hydraulic System Testing And Adjusting section.

Main Control Valve
(1) Auxiliary cylinder relief valve. (2) Auxiliary cylinder relief valve. (3) Tilt head end relief valve. (4) Tilt rod end relief valve.

Relief Valve
(5) Locknut. (6) Cover nut. (7) Adjusting screw.

1. Lower the bucket so it is on the ground and can not be tilted. To gain access to the tilt relief valves, remove the cover from the front of the loader frame. Release hydraulic system pressure.

2. Carefully loosen the tank fill cap to release any pressure in the tank. Tighten the cap.

3. Install a connector, hose and pressure gauge at inline pressure tap (located in tilt cylinder rod end hydraulic line).

NOTE: The tilt rod end relief valve has a higher pressure setting than the main relief valve. In order to set properly, the relief valve must be removed and placed in a test bench, or a remote pump must be installed.

4. Remove the hose from the rod end of the main control valve and install a tee between the control valve and the hose.

5. Assemble necessary fittings and attach 3S6224 pump.

NOTE: 3S6224 pump reservoir only contains 7.58 L (2 gal U.S.) of oil. Ensure the pump does not run out of oil.

6. Start the pump and slowly increase pump pressure.

7. The pressure setting of tilt rod end relief valve (4) should be 25 500 ± 350 kPa (3700 ± 50 psi).

8. If the opening pressure of the relief valve is not to specification it will be necessary to adjust the valve.

9. Stop the pump.

10. Remove cover nut (6). Loosen locknut (5) and turn screw (7) clockwise for an increase or counterclockwise for a decrease in the pressure setting of the relief valve.

11. After screw (7) is turned for an adjustment, tighten locknut (5).

12. Replace and tighten cover nut (6).

13. Start the pump. Repeat steps 6, 7 and 8.

14. If pressure is correct, stop the pump.

15. If pressure is not correct, repeat steps 9, 10, 11, 12 and 13.

16. When pressure setting is correct, stop the pump. Remove the test equipment.

Tilt Cylinder Head End Relief Valve

Show/hide table

Make reference to WARNING on first page of Loader Hydraulic System Testing And Adjusting section.

Main Control Valve
(1) Auxiliary cylinder relief valve. (2) Auxiliary cylinder relief valve. (3) Tilt head end relief valve. (4) Tilt rod end relief valve.

Relief Valve
(5) Locknut. (6) Cover nut. (7) Adjusting screw.

1. Lower the bucket so it is on the ground and can not be tilted. To gain access to the tilt relief valves, remove the cover from the front of the loader frame. Release hydraulic system pressure.

2. Carefully loosen the tank fill cap to release any pressure in the tank. Tighten the cap.

3. Install a connector, hose and pressure gauge at inline pressure tap (located in tilt cylinder head end hydraulic line).

NOTE: The tilt head end relief valve has a higher pressure setting than the main relief valve. In order to set properly, the relief valve must be removed and placed in a test bench, or a remote pump must be installed.

4. Remove the hose from the head end of the main control valve and install a tee between the control valve and the hose.

5. Assemble necessary fittings and attach 3S6224 pump.

NOTE: 3S6224 pump reservoir only contains 7.58 L (2 gal U.S.) of oil. Ensure the pump does not run out of oil.

6. Start the pump and slowly increase pump pressure.

7. The pressure setting of tilt head end relief valve (3) should be 25 500 ± 350 kPa (3700 ± 50 psi).

8. If the opening pressure of the relief valve is not to specification it will be necessary to adjust the valve.

9. Stop the pump.

10. Remove cover nut (6). Loosen locknut (5) and turn screw (7) clockwise for an increase or counterclockwise for a decrease in the pressure setting of the relief valve.

11. After screw (7) is turned for an adjustment, tighten locknut (5).

12. Replace and tighten cover nut (6).

13. Start the pump. Repeat steps 6, 7 and 8.

14. If pressure is correct, stop the pump.

15. If pressure is not correct, repeat steps 9, 10, 11, 12 and 13.

16. When pressure setting is correct, stop the pump. Remove the test equipment.

Auxiliary Cylinder Relief Valve (Optional)

Show/hide table

Make reference to WARNING on first page of Loader Hydraulic System Testing And Adjusting section.

Main Control Valve
(1) Auxiliary cylinder relief valve. (2) Port. (3) Port. (4) Auxiliary cylinder relief valve.

Relief Valve
(5) Locknut. (6) Cover nut. (7) Adjusting screw.

1. Lower the bucket so it is on the ground and can not be tilted. To gain access to the auxiliary relief valves, remove the cover from the front of the loader frame. Release hydraulic system pressure.

2. Carefully loosen the tank fill cap to release any pressure in the tank. Tighten the cap.

3. Install a tee, pressure tap, connector, hose and pressure gauge in auxiliary line at port (2).

NOTE: The auxiliary relief valve has a higher pressure setting than the main relief valve. In order to set properly, the relief valve must be removed and placed in a test bench, or a remote pump must be installed.

4. Remove the hose from the main control valve and install a tee between the control valve and the hose.

5. Assemble necessary fittings and attach 3S6224 pump.

NOTE: 3S6224 pump reservoir only contains 7.58 L (2 gal U.S.) of oil. Ensure the pump does not run out of oil.

6. Start the pump and slowly increase pump pressure.

7. The pressure setting of auxiliary relief valve (1) should be 25 500 ± 350 kPa (3700 ± 50 psi).

8. If the opening pressure of the relief valve is not to specification it will be necessary to adjust the valve.

9. Stop the pump.

10. Remove cover nut (6). Loosen locknut (5) and turn screw (7) clockwise for an increase or counterclockwise for a decrease in the pressure setting of the relief valve.

11. After screw (7) is turned for an adjustment, tighten locknut (5).

12. Replace and tighten cover nut (6).

13. Start the pump. Repeat steps 6, 7 and 8.

14. If pressure is correct, stop the pump.

15. If pressure is not correct, repeat steps 9, 10, 11, 12 and 13.

16. When pressure setting is correct, stop the pump. Remove the test equipment.

Auxiliary Cylinder Relief Valve (Optional)

Show/hide table

Make reference to WARNING on first page of Loader Hydraulic System Testing And Adjusting section.

Main Control Valve
(1) Auxiliary cylinder relief valve. (2) Port. (3) Port. (4) Auxiliary cylinder relief valve.

Relief Valve
(5) Locknut. (6) Cover nut. (7) Adjusting screw.

2. Carefully loosen the tank fill cap to release any pressure in the tank. Tighten the cap.

3. Install a tee, pressure tap, connector, hose and pressure gauge in auxiliary line at port (3).

4. Remove the hose from the main control valve and install a tee between the control valve and the hose.

5. Assemble necessary fittings and attach 3S6224 pump.

NOTE: 3S6224 pump reservoir only contains 7.58 L (2 gal U.S.) of oil. Ensure the pump does not run out of oil.

6. Start the pump and slowly increase pump pressure.

7. The pressure setting of auxiliary relief valve (4) should be 25 500 ± 350 kPa (3700 ± 50 psi).

8. If the opening pressure of the relief valve is not to specification it will be necessary to adjust the valve.

9. Stop the pump.

10. Remove cover nut (6). Loosen locknut (5) and turn screw (7) clockwise for an increase or counterclockwise for a decrease in the pressure setting of the relief valve.

11. After screw (7) is turned for an adjustment, tighten locknut (5).

12. Replace and tighten cover nut (6).

13. Start the pump. Repeat steps 6, 7 and 8.

14. If pressure is correct, stop the pump.

15. If pressure is not correct, repeat steps 9, 10, 11, 12 and 13.

16. When pressure setting is correct, stop the pump. Remove the test equipment.

Relief Valves - IT14G

Show/hide table

Make reference to WARNING on first page of Loader Hydraulic System Testing And Adjusting section.

1. Lower the bucket/attachment so it is on the ground and can not be tilted. Remove the cover that is over the control valve, from the front of the loader frame to gain access to main and line relief valves.

2. Increase the temperature of the oil up to normal operating temperature.

Main Relief Valve

Show/hide table

Make reference to WARNING on first page of Loader Hydraulic System Testing And Adjusting section.

Main Control Valve
(1) Pressure tap. (2) Main relief valve.

Main Relief Valve
(3) Cap. (4) Locknut. (5) Adjusting screw.

1. Lower the bucket/attachment so it is on the ground and can not be tilted. To gain access to the main relief valve, remove the cover from the front of the loader frame. Release hydraulic system pressure.

2. Carefully loosen the tank fill cap to release any pressure in the tank. Tighten the cap.

3. Install a connector, hose and pressure gauge at pressure tap (1).

4. Start the engine.

5. Raise the bucket/attachment off the ground. Tilt back the bucket/attachment until the tilt cylinder rods are fully retracted.

6. Increase engine rpm to high idle, look at the test gauge and move the tilt control lever to the TILT BACK position.

7. The pressure setting of main relief valve (2) should be 24 150 ± 350 kPa (3500 ± 50 psi).

NOTE: Do not keep the control lever in the TILT BACK position, at the relief valve setting, more than 5 seconds.

8. If the opening pressure of the relief valve is not to specification it will be necessary to adjust the valve.

9. Stop the engine.

10. Remove cap (3). Loosen locknut (4) and turn screw (5) clockwise for an increase or counterclockwise for a decrease in the pressure setting of the relief valve.

11. After screw (5) is turned for an adjustment, tighten locknut (4).

12. Start the engine. Repeat steps 5, 6 and 7.

13. If pressure is correct, lower the bucket/attachment to the ground and stop the engine.

14. If pressure is not correct, repeat steps 10, 11, 12 and 13.

15. When pressure setting is correct, stop the engine. Remove the test equipment.

Tilt Cylinder Rod End Relief Valve

Show/hide table

Make reference to WARNING on first page of Loader Hydraulic System Testing And Adjusting section.

Main Control Valve
(1) Auxiliary cylinder relief valve. (2) Auxiliary cylinder relief valve. (3) Coupler rod end relief valve. (4) Coupler head end relief valve. (5) Tilt head end relief valve. (6) Tilt rod end relief valve.

Relief Valve
(7) Locknut. (8) Cover nut. (9) Adjusting screw.

1. Lower the bucket/attachment so it is on the ground and can not be tilted. To gain access to the tilt relief valves, remove the cover from the front of the loader frame. Release hydraulic system pressure.

2. Carefully loosen the tank fill cap to release any pressure in the tank. Tighten the cap.

3. Install a connector, hose and pressure gauge at inline pressure tap (located in tilt cylinders rod end hydraulic line).

4. Remove the hose from the rod end of the main control valve and install a tee between the control valve and the hose.

5. Assemble necessary fittings and attach 3S6224 pump.

NOTE: 3S6224 pump reservoir only contains 7.58 L (2 gal U.S.) of oil. Ensure the pump does not run out of oil.

6. Start the pump and slowly increase pump pressure.

7. The pressure setting of tilt rod end relief valve (6) should be 25 500 ± 350 kPa (3700 ± 50 psi).

8. If the opening pressure of the relief valve is not to specification it will be necessary to adjust the valve.

9. Stop the pump.

10. Remove cover nut (8). Loosen locknut (7) and turn screw (9) clockwise for an increase or counterclockwise for a decrease in the pressure setting of the relief valve.

11. After screw (9) is turned for an adjustment, tighten locknut (7).

12. Replace and tighten cover nut (8).

13. Start the pump. Repeat steps 6, 7 and 8.

14. If pressure is correct, stop the pump.

15. If pressure is not correct, repeat steps 9, 10, 11, 12 and 13.

16. When pressure setting is correct, stop the pump. Remove the test equipment.

Tilt Cylinder Head End Relief Valve

Show/hide table

Make reference to WARNING on first page of Loader Hydraulic System Testing And Adjusting section.

Relief Valve
(7) Locknut. (8) Cover nut. (9) Adjusting screw.

2. Carefully loosen the tank fill cap to release any pressure in the tank. Tighten the cap.

3. Install a connector, hose and pressure gauge at inline pressure tap (located in tilt cylinders head end hydraulic line).

4. Start the engine.

5. Raise the bucket/attachment off the ground. Dump the bucket/attachment until the tilt cylinder rods are fully extended.

6. Increase engine rpm to high idle, look at the test gauge and move the tilt control lever to the DUMP position.

7. The pressure setting of tilt head end relief valve (5) should be 13 100 ± 350 kPa (1900 ± 50 psi).

NOTE: Do not keep the control lever in the DUMP position, at the relief valve setting, more than 5 seconds.

8. If the opening pressure of the relief valve is not to specification it will be necessary to adjust the valve.

9. Stop the engine.

10. Remove cover nut (8). Loosen locknut (7) and turn screw (9) clockwise for an increase or counterclockwise for a decrease in the pressure setting of the relief valve.

11. After screw (9) is turned for an adjustment, tighten locknut (7).

12. Replace and tighten cover nut (8).

13. Start the engine. Repeat steps 7, 8 and 9.

14. If pressure is correct, lower the bucket/attachment to the ground and stop the engine.

15. If pressure is not correct, repeat steps 12, 13, 14 and 15.

16. When pressure setting is correct, stop the engine. Remove the test equipment.

Coupler Cylinder Head End Relief Valve

Show/hide table

Make reference to WARNING on first page of Loader Hydraulic System Testing And Adjusting section.

Relief Valve
(8) Locknut. (9) Cover nut. (10) Adjusting screw.

1. Lower the bucket/attachment so it is on the ground and can not be tilted. To gain access to the coupler relief valves, remove the cover from the front of the loader frame. Release hydraulic system pressure.

2. Carefully loosen the tank fill cap to release any pressure in the tank. Tighten the cap.

3. Install a connector, hose and pressure gauge at pressure tap (7).

4. Start the engine.

5. Lower the bucket/attachment to the ground. Move the control lever to the ENGAGE position until the coupler cylinder rods are fully extended.

6. Increase engine rpm to high idle, look at the test gauge and move the coupler control lever to the ENGAGE position.

7. The pressure setting of coupler head end relief valve (4) should be 20 700 ± 350 kPa (3000 ± 50 psi).

NOTE: Do not keep the control lever in the ENGAGE position, at the relief valve setting, more than 5 seconds.

8. If the opening pressure of the relief valve is not to specification it will be necessary to adjust the valve.

9. Stop the engine.

10. Remove cover nut (9). Loosen locknut (8) and turn screw (10) clockwise for an increase or counterclockwise for a decrease in the pressure setting of the relief valve.

11. After screw (10) is turned for an adjustment, tighten locknut (8).

12. Replace and tighten cover nut (9).

13. Start the engine. Repeat steps 7, 8 and 9.

14. If pressure is correct, stop the engine.

15. If pressure is not correct, repeat steps 12, 13, 14 and 15.

16. When pressure setting is correct, stop the engine. Remove the test equipment.

Coupler Cylinder Rod End Relief Valve

Show/hide table

Make reference to WARNING on first page of Loader Hydraulic System Testing And Adjusting section.

Relief Valve
(8) Locknut. (9) Cover nut. (10) Adjusting screw.

2. Carefully loosen the tank fill cap to release any pressure in the tank. Tighten the cap.

3. Install a connector, hose and pressure gauge at pressure tap (7).

4. Start the engine.

5. Lower the bucket/attachment to the ground. Move the control lever to the DISENGAGE position until the coupler cylinder rods are fully retracted.

6. Increase engine rpm to high idle, look at the test gauge and move the coupler control lever to the DISENGAGE position.

7. The pressure setting of coupler rod end relief valve (3) should be 20 700 ± 350 kPa (3000 ± 50 psi).

NOTE: Do not keep the control lever in the DISENGAGE position, at the relief valve setting, more than 5 seconds.

8. If the opening pressure of the relief valve is not to specification it will be necessary to adjust the valve.

9. Stop the engine.

10. Remove cover nut (9). Loosen locknut (8) and turn screw (10) clockwise for an increase or counterclockwise for a decrease in the pressure setting of the relief valve.

11. After screw (10) is turned for an adjustment, tighten locknut (8).

12. Replace and tighten cover nut (9).

13. Start the engine. Repeat steps 7, 8 and 9.

14. If pressure is correct, stop the engine.

15. If pressure is not correct, repeat steps 12, 13, 14 and 15.

16. When pressure setting is correct, stop the engine. Remove the test equipment.

Auxiliary Cylinder Relief Valve

Show/hide table

Make reference to WARNING on first page of Loader Hydraulic System Testing And Adjusting section.

Relief Valve
(8) Locknut. (9) Cover nut. (10) Adjusting screw.

1. Lower the bucket/attachment so it is on the ground and can not be tilted. To gain access to the auxiliary relief valves, remove the cover from the front of the loader frame. Release hydraulic system pressure.

2. Carefully loosen the tank fill cap to release any pressure in the tank. Tighten the cap.

3. Install a connector, hose and pressure gauge at pressure tap (7).

4. Start the engine.

5. Lower the bucket/attachment to the ground. Move the auxiliary control lever back to route pressure oil to auxiliary relief valve (1).

6. Increase engine rpm to high idle, look at the test gauge and move the auxiliary control lever fully back.

7. The pressure setting of auxiliary relief valve (1) should be 20 700 ± 350 kPa (3000 ± 50 psi).

NOTE: Do not keep the control lever in the back position, at the relief valve setting, more than 5 seconds.

8. If the opening pressure of the relief valve is not to specification it will be necessary to adjust the valve.

9. Stop the engine.

10. Remove cover nut (9). Loosen locknut (8) and turn screw (10) clockwise for an increase or counterclockwise for a decrease in the pressure setting of the relief valve.

11. After screw (10) is turned for an adjustment, tighten locknut (8).

12. Replace and tighten cover nut (9).

13. Start the engine. Repeat steps 7, 8 and 9.

14. If pressure is correct, stop the engine.

15. If pressure is not correct, repeat steps 12, 13, 14 and 15.

16. When pressure setting is correct, stop the engine. Remove the test equipment.

Auxiliary Cylinder Relief Valve

Show/hide table

Make reference to WARNING on first page of Loader Hydraulic System Testing And Adjusting section.

Relief Valve
(8) Locknut (9) Cover nut. (10) Adjusting screw.

2. Carefully loosen the tank fill cap to release any pressure in the tank. Tighten the cap.

3. Install a connector, hose and pressure gauge at pressure tap (7).

4. Start the engine.

5. Lower the bucket/attachment to the ground. Move the auxiliary control lever forward to route pressure oil to auxiliary relief valve (2).

6. Increase engine rpm to high idle, look at the test gauge and move the auxiliary control lever fully forward.

7. The pressure setting of auxiliary relief valve (2) should be 20 700 ± 350 kPa (3000 ± 50 psi).

NOTE: Do not keep the control lever in the forward position, at the relief valve setting, more than 5 seconds.

8. If the opening pressure of the relief valve is not to specification it will be necessary to adjust the valve.

9. Stop the engine.

10. Remove cover nut (9). Loosen locknut (8) and turn screw (10) clockwise for an increase or counterclockwise for a decrease in the pressure setting of the relief valve.

11. After screw (10) is turned for an adjustment, tighten locknut (8).

12. Replace and tighten cover nut (9).

13. Start the engine. Repeat steps 7, 8 and 9.

14. If pressure is correct, stop the engine.

15. If pressure is not correct, repeat steps 12, 13, 14 and 15.

16. When pressure setting is correct, stop the engine. Remove the test equipment.

Lift Kickout And Bucket/Attachment Positioner Adjustment

Refer to SEBU6868, 914G Wheel Loader, Operation & Maintenance Manual, SEBU6869, IT14G Integrated Toolcarrier, Operation & Maintenance Manual and SENR6773, 914G Wheel Loader And IT14G Integrated Toolcarrier, Hydraulic System Specifications for procedures.