330B Excavator Hydraulic System Caterpillar

Illustration 1	g00344492
Flow meter tool layout (1) Swing motor (2) Connector at swing motor (3) 6V-9840 Swivel Tee (4) Makeup line (6) 6V-9512 Plug (7) Negative flow control line (upper pump) (10) 6V-9508 Plug (12) 4C-9910 Portable hydraulic tester (flow meter) (16) Delivery line for main pump (18) Upper pump (20) Negative flow control line (lower pump) (22) Lower pump (30) 5K-9090 O-Ring seal (31) 5P-0201 Hose (32) 5P-1010 Sleeve (33) 4C-8767 Coupling (34) 7M-8484 O-Ring seal (35) 4C-6481 Coupler assembly (36) 4C-6482 Nipple assembly (37) 4I-6141 Coupling assembly (38) 8C-9026 Adapter (39) 6K-6307 O-Ring seal (40) 6V-9854 Swivel elbow (42) 6V-8397 O-Ring seal

Illustration 2	g00344493
Tool setup (8) 8T-0861 Pressure gauge (9) Pressure tap (upper pump delivery pressure) (13) Pressure tap (pilot oil manifold) (14) 8T-8902 Tee (19) 8T-0855 Pressure gauge (20) 6V-3989 Unvalved nipple (21) 6V-4143 Coupler assembly (27) 6V-9508 Plug (28) Test port (negative flow control) (29) 6V-3014 Hose (41) 6V-9829 Cap (43) 3J-1907 O-Ring seal (45) 6V-3965 Nipple assembly

Illustration 3	g00369874
Pilot oil manifold (11) Pilot oil manifold (13) Pressure tap (25) Pilot relief valve

Illustration 4	g00370212
Swing motor (top view) (1) Swing motor (2) Connector (4) Makeup line

Illustration 5	g00344501
Portable hydraulic tester (flow meter) (12) Portable hydraulic tester (flow meter) (23) Multitach (26) Valve

Illustration 6	g00344504
Circuit Diagram (1) Swing Motor (2) Connector (3) Tee (4) Makeup line (5) Main control valves (6) Plug (7) Negative flow control line (upper pump) (8) Pressure gauge (9) Pressure tap (upper pump delivery pressure) (10) Plug (11) Pilot oil manifold (12) Portable hydraulic tester (flow meter) (13) Pressure tap (14) Tee (15) Delivery line (lower pump) (16) Delivery line (upper pump) (17) Test hose (18) Upper pump (19) Pressure gauge (20) Negative flow control line (lower pump) (21) Pressure tap (lower pump delivery pressure) (22) Lower pump (23) Multitach group (24) Engine (27) Plug (28) Negative flow signal pressure port (41) Cap (44) Negative flow signal pressure port (46) Test hose

Preparation

Upper Pump

Illustration 7	g00369872
Pump compartment (7) Negative flow control line (upper pump) (9) Pressure tap (upper pump delivery pressure) (16) Delivery line (upper pump) (18) Upper pump (22) Lower pump

1. Position the machine on level ground.

2. Stop the engine.

3. Release the pressure in the hydraulic system. Refer to Testing And Adjusting, "Hydraulic System Pressure - Release".

4. Install the following tools in accordance with the circuit diagram. Refer to Illustration 6.

   1. Disconnect delivery line (16) from upper pump (18) .

   2. Install plug (6) and seal (30) to the end of delivery line (16) .

   3. Disconnect makeup line (4) from swing motor (1) .

   4. Install tee (3) to connector (2) of swing motor (1) .

   5. Connect makeup line (4) to tee (3) .

   6. Connect portable hydraulic tester (12) between upper pump (18) and makeup line (4) .

   7. Connect 60000 kPa (8700 psi) pressure gauge (8) to pressure tap (9) for upper pump delivery pressure.

   8. Install multitach group (23) on engine (24). This is used to monitor engine speed.

   9. Disconnect negative flow control line (7) from upper pump (18). Install plug (10) and seal (42) to the end of negative flow control line (7) .

   10. Connect one end of test hose (17) to negative flow signal pressure port (28) of upper pump (18) .

   11. Install tees (14) to the other end of test hose (17). Refer to Illustration 6.

   12. Connect a 4000 kPa (580 psi) pressure gauge (19) to tee (14) .

   13. Connect one end of test hose (46) to pressure tap (13) of pilot oil manifold (11). Connect the other end of test hose (46) to tee (14) .

Lower Pump

Illustration 8	g00503310
Pump compartment (15) Delivery line (lower pump) (18) Upper pump (20) Negative flow control line (lower pump) (21) Pressure tap (lower pump delivery pressure) (22) Lower pump

1. Position the machine on level ground.

2. Stop the engine.

3. Release the pressure in the hydraulic system. Refer to Testing And Adjusting, "Hydraulic System Pressure - Release".

4. Install the following tools in accordance with the circuit diagram. Refer to Illustration 6.

   1. Disconnect delivery line (15) from lower pump (22) .

   2. Install plug (6) and seal (30) to the end of delivery line (15) .

   3. Disconnect makeup line (4) from swing motor (1) .

   4. Install tee (3) to connector (2) of swing motor (1) .

   5. Connect makeup line (4) to tee (3) .

   6. Connect portable hydraulic tester (12) between lower pump (22) and makeup line (4) .

   7. Connect 60000 kPa (8700 psi) pressure gauge (8) to pressure tap (21) for lower pump delivery pressure.

   8. Install multitach group (23) on engine (24). This is used to monitor engine speed.

   9. Disconnect negative flow control line (20) from lower pump (22). Install plug (10) and seal (42) to the end of negative flow control line (20) .

   10. Connect one end of test hose (17) to negative flow signal pressure port (44) of lower pump (22) .

   11. Install tees (14) to the other end of test hose (17). Refer to Illustration 6.

   12. Connect a 4000 kPa (580 psi) pressure gauge (19) to tee (14) .

   13. Connect one end of test hose (46) to pressure tap (13) of pilot oil manifold (11). Connect the other end of test hose (46) to tee (14) .

Test

Note: Perform the test for the upper pump and the test for the lower pump one at a time.

Show/hide table

To prevent personal injury or equipment damage from failure of the hydraulic test equipment or associated circuit components because of blocked pump flow, make sure that the test equipment valves are fully open before starting the engine.

Show/hide table

To prevent personal injury and/or equipment damage from failed lines or components while the hydraulic test equipment is returned to the open flow position, slowly open the hydraulic test equipment valve while monitoring the pump flow. If pump flow does not increase as the valve is opened, shut the engine off and determine what is preventing the pump from upstroking.

1. Start the engine.

2. Place the machine controls at the following settings: Power Mode, engine speed dial "10" and AEC switch OFF.

   Reference: Make reference to Testing And Adjusting, "Operational Checks" for engine rpm settings.

3. Increase the hydraulic oil temperature to 55° ± 5°C (131° ± 9°F).

4. Turn valve (26) on portable hydraulic tester (12) clockwise until the pump delivery pressure is 6850 kPa (1000 psi).

5. Adjust pilot relief valve (25) on pilot oil manifold (11) until pressure gauge (19) that is connected to tee (14) indicates 2490 kPa (360 psi).

6. Record the negative flow at 2490 kPa (360 psi) in Table 1.

Illustration 9	g00503306
P-Q characteristic curve

Note: Specifications for flow rates are based on an engine speed of 1800 rpm. To get more accurate test results, measured flow should be corrected with the following calculation.

Flow measurements must be done in pressure rise.