914G and 914G2 Compact Wheel Loaders and IT14G and IT14G2 Integrated Toolcarrier Hydraulic System Caterpillar

IT14G and IT14G2

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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.

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Sudden movement or accidental starting of the machine can cause personal injury or death to persons on or near the machine. To prevent personal injury or death, perform the following: Park the machine on a smooth, level surface. Lower the work tool to the ground and engage the parking brake. Stop the engine and remove the key. Block the wheels and install the steering frame lock.

Relief Valve for the Rod End of the Tilt Cylinder

Illustration 1	g01043649
Bank Valve (1) Auxiliary cylinder relief valve (2) Auxiliary cylinder relief valve (3) Relief valve for the rod end of the auxiliary circuit (4) Relief valve for the head end of the auxiliary circuit (5) Relief valve for the head end of the tilt cylinder (6) Relief valve for the rod end of the tilt cylinder

Illustration 2	g01043710
Line relief valve (7) Locknut (8) Adjusting screw

1. Lower the work tool so that the work tool is on the ground and the work tool cannot be tilted. To gain access to the line relief valves, remove the cover from the front of the frame. Release the hydraulic system pressure.

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

3. Install 198-4240 Digital Pressure Indicator into the pressure tap that is located in the hydraulic line for the rod end of the tilt cylinder.

   Note: The relief valve for the rod end of the tilt cylinder has a higher pressure setting than the main relief valve. In order to set the relief valve for the rod end of the tilt cylinder, 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 main control valve and the hose.

5. Assemble the necessary fittings from 8T-5320 Hydraulic Test Group and attach 3S-6224 Electric Hydraulic Pump Gp .

   Note: 3S-6224 Electric Hydraulic Pump Gp only contains 7.58 L (2 US gal) of oil. Ensure that the pump does not run out of oil.

6. Start the pump and slowly increase the pump pressure.

7. The digital pressure indicator should read 25500 ± 350 kPa (3700 ± 50 psi). The readout on the digital pressure indicator is the pressure setting of the relief valve for the rod end of the tilt cylinder.

8. Stop the pump.

9. If the opening pressure of the relief valve is not within the specification, Adjust the pressure setting of the relief valve. Refer to Step 11.

10. If the opening pressure of the relief valve is within the specification, refer to Step 17.

11. Remove the cover on the relief valve. Loosen locknut (7) and turn screw (8). Turn screw (8) clockwise in order to increase the pressure setting of the relief valve. Turn screw (8) in order to decrease the pressure setting of the relief valve.

12. After screw (8) has been turned for an adjustment, tighten locknut (7) .

13. Replace the cover on the relief valve.

14. Start the pump and repeat Step 6 through Step 10.

15. If the pressure setting of the relief valve is correct, stop the pump.

16. If the pressure setting of the relief valve is not correct, stop the pump and repeat Step 11 through Step 14.

17. When the pressure setting is correct, stop the pump. Remove the test equipment and hook up all of the hydraulic lines.

Relief Valve for the Rod End of the Tilt Cylinder

Illustration 3	g01043682
Bank Valve (9) Relief valve for the auxiliary cylinder (10) Relief valve for the auxiliary cylinder (11) Relief valve for the rod end of the auxiliary circuit (12) Relief valve for the head end of the auxiliary circuit (13) Relief valve for the head end of the tilt cylinder (14) Relief valve for the rod end of the tilt cylinder

Illustration 4	g01043684
Line relief valve (15) Locknut (16) Adjusting screw

1. Lower the work tool so that the work tool is on the ground and the work tool cannot be tilted. To gain access to the line relief valves, remove the cover from the front of the frame. Release the hydraulic system pressure.

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

3. Install 198-4240 Digital Pressure Indicator on the pressure tap that is located in the hydraulic line for the head end of the tilt cylinder.

4. Start the engine.

5. Raise the bucket off the ground. Dump the work tool until the rods for the tilt cylinder are fully extended.

6. Increase the engine rpm to high idle. Look at the digital pressure indicator and move the tilt control lever to the DUMP position.

7. The digital pressure indicator should show a pressure reading of 13000 ± 350 kPa (1900 ± 50 psi). This pressure reading is the setting of the pressure relief valve.

   Note: Do not keep the control lever in the DUMP position and at the relief valve setting for more than 5 seconds.

8. If the pressure setting of the relief valve is correct, refer to Step 14.

9. If the pressure setting of the relief valve is not to the required specification, adjust the valve.

10. Stop the engine.

11. Remove the protective cap from the line relief valve. Loosen locknut (15). Turn screw (16) clockwise in order to increase the pressure setting of the relief valve. Turn screw (16) counterclockwise in order to decrease the pressure setting of the relief valve.

12. After screw (16) has been turned for an adjustment, tighten locknut (15) .

13. Start the engine. Repeat Step 5 through Step 9 in order to test the pressure setting for the relief valve.

14. If the pressure setting of the relief valve is correct, lower the work tool to the ground and stop the engine.

15. Repeat Step 11 through step 13 if the pressure setting for the relief valve is incorrect.

16. When the pressure setting is correct, stop the engine.

17. Remove all test equipment.

Relief Valve for the Head End of the Auxiliary Circuit

Illustration 5	g01043720
Bank Valve (17) Relief valve for the auxiliary cylinder (18) Relief valve for the auxiliary cylinder (19) Relief valve for the rod end of the auxiliary circuit (20) Relief valve for the head end of the auxiliary circuit (21) Relief valve for the head end of the tilt cylinder (22) Relief valve for the rod end of the tilt cylinder (23) Passage for pressure tap

Illustration 6	g01043692
Line relief valve (24) Locknut (25) Adjusting screw

1. Lower the work tool so that the work tool is on the ground and the work tool cannot be tilted. To gain access to the line relief valves, remove the cover from the front of the frame. Release the hydraulic system pressure.

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

3. Install 198-4240 Digital Pressure Indicator at the pressure tap in passage (23) .

4. Start the engine.

5. Lower the work tool to the ground. Move the coupler control lever to the ENGAGE position until the rods for the coupler cylinder are fully extended.

6. Increase the engine rpm to high idle. Look at the digital pressure indicator and move the coupler control lever to the ENGAGE position.

7. The digital pressure indicator should show a pressure reading of 20700 ± 350 kPa (3000 ± 50 psi). This pressure reading is the setting of the pressure relief valve.

   Note: Do not keep the control lever in the ENGAGE position and at the relief valve setting for more than 5 seconds.

8. If the pressure setting of the relief valve is correct, refer to Step 14.

9. If the pressure setting of the relief valve is not to the required specification, adjust the valve.

10. Stop the engine.

11. Remove the protective cap from the line relief valve. Loosen locknut (24). Turn screw (25) clockwise in order to increase the pressure setting of the relief valve. Turn screw (25) counterclockwise in order to decrease the pressure setting of the relief valve.

12. After screw (25) has been turned for an adjustment, tighten locknut (24) .

13. Start the engine. Repeat Step 5 through Step 9 in order to test the pressure setting for the relief valve.

14. If the pressure setting of the relief valve is correct, lower the work tool to the ground and stop the engine.

15. Repeat Step 11 through step 13 if the pressure setting for the relief valve is incorrect.

16. When the pressure setting is correct, stop the engine.

17. Remove all test equipment.

Relief Valve for the Rod End of the Auxiliary Circuit

Illustration 7	g01043721
Bank Valve (26) Relief valve for the auxiliary cylinder (27) Relief valve for the auxiliary cylinder (28) Relief valve for the rod end of the auxiliary circuit (29) Relief valve for the head end of the auxiliary circuit (30) Relief valve for the head end of the tilt cylinder (31) Relief valve for the rod end of the tilt cylinder (32) Passage for pressure tap

Illustration 8	g01043696
Line relief valve (33) Locknut (34) Adjusting screw

1. Lower the work tool so that the work tool is on the ground and the work tool cannot be tilted. To gain access to the line relief valves, remove the cover from the front of the frame. Release the hydraulic system pressure.

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

3. Install 198-4240 Digital Pressure Indicator at the pressure tap in passage (32) .

4. Start the engine.

5. Lower the work tool to the ground. Move the coupler control lever to the DISENGAGE position until the rods for the coupler cylinder are fully extended.

6. Increase the engine rpm to high idle. Look at the digital pressure indicator and move the coupler control lever to the DISENGAGE position.

7. The digital pressure indicator should show a pressure reading of 20700 ± 350 kPa (3000 ± 50 psi). This pressure reading is the setting of the pressure relief valve.

   Note: Do not keep the control lever in the DISENGAGE position and at the relief valve setting for more than 5 seconds.

8. If the pressure setting of the relief valve is correct, refer to Step 14.

9. If the pressure setting of the relief valve is not to the required specification, adjust the valve.

10. Stop the engine.

11. Remove the protective cap from the line relief valve. Loosen locknut (33). Turn screw (34) clockwise in order to increase the pressure setting of the relief valve. Turn screw (34) counterclockwise in order to decrease the pressure setting of the relief valve.

12. After screw (34) has been turned for an adjustment, tighten locknut (33) .

13. Start the engine. Repeat Step 5 through Step 9 in order to test the pressure setting for the relief valve.

14. If the pressure setting of the relief valve is correct, lower the work tool to the ground and stop the engine.

15. Repeat Step 11 through step 13 if the pressure setting for the relief valve is incorrect.

16. When the pressure setting is correct, stop the engine.

17. Remove all test equipment.

Relief Valves for the Auxiliary Circuit

Illustration 9	g01043722
Bank Valve (35) Relief valve for the auxiliary cylinder (36) Relief valve for the auxiliary cylinder (37) Relief valve for the rod end of the auxiliary circuit (38) Relief valve for the head end of the auxiliary circuit (39) Relief valve for the head end of the tilt cylinder (40) Relief valve for the rod end of the tilt cylinder (41) Passage for pressure tap

Illustration 10	g01043698
Line relief valve (42) Locknut (43) Adjusting screw

1. Lower the work tool so that the work tool is on the ground and the work tool cannot be tilted. To gain access to the line relief valves, remove the cover from the front of the frame. Release the hydraulic system pressure.

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

3. Install 198-4240 Digital Pressure Indicator at the pressure tap in passage (41) .

4. Start the engine.

5. Lower the work tool to the ground. Move the auxiliary control lever forward in order to route the pressure oil to the relief valve for the auxiliary cylinder.

6. Increase the engine rpm to high idle. Look at the digital pressure indicator and move the auxiliary control lever fully forward.

7. The digital pressure indicator should show a pressure reading of 20700 ± 350 kPa (3000 ± 50 psi). This pressure reading is the setting of the pressure relief valve.

   Note: Do not keep the control lever in the forward position and at the relief valve setting for more than 5 seconds.

8. If the pressure setting of the relief valve is correct, refer to Step 14.

9. If the pressure setting of the relief valve is not to the required specification, adjust the valve.

10. Stop the engine.

11. Remove the protective cap from the line relief valve. Loosen locknut (42). Turn screw (43) clockwise in order to increase the pressure setting of the relief valve. Turn screw (43) counterclockwise in order to decrease the pressure setting of the relief valve.

12. After screw (43) has been turned for an adjustment, tighten locknut (42) .

13. Start the engine. Repeat Step 5 through Step 9 in order to test the pressure setting for the relief valve.

14. If the pressure setting of the relief valve is correct, lower the work tool to the ground and stop the engine.

15. Repeat Step 11 through step 13 if the pressure setting for the relief valve is incorrect.

16. When the pressure setting is correct, stop the engine.

17. Remove all test equipment.