322B Excavator Hydraulic System Caterpillar

Illustration 1	g00304069
Electronic controller (1) Alarm lamp (2) Electronic controller

Illustration 2	g00304070
Right console (3) Right console (4) Operator monitor panel

Note: Before starting main pump flow tests, check operator monitor panel (4) and alarm lamp (1) on electronic controller (2) for normal operation. If no faults are present, perform the operational checks. Refer to Testing And Adjusting, "Operational Checks".

Note: If the operational checks (cycle time) indicate that slow speed of an implement is common to the circuits of one pump, the problem is most likely in the hydraulic system. Then perform the pump flow tests. Refer to Testing And Adjusting, "Piston Pump (Main) - Test".

Note: The engine, the fuel, or the working altitude may be the problem if the operational checks indicate that slow speed of an implement is common to both pump circuits.

Main Pump Constant Horsepower Control Test

Illustration 3	g00352182
Flow meter tool layout (1) Swing motor (2) Connector at swing motor (3) 6V-9840 Swivel tee (4) Makeup line (6) Negative flow control line (upper pump) (7) 6V-9512 Plug (8) 6V-9508 Plug (9) 8T-0861 Pressure gauge (10) Pressure tap (upper pump delivery pressure) (11) 4C-9910 Portable hydraulic tester (flow meter) (12) Delivery line for lower pump (13) Delivery line for upper pump (14) 8T-0856 Pressure gauge (15) Pressure tap (power shift pressure) (16) Upper pump (17) Negative flow control line (lower pump) (18) Pressure Tap (lower pump delivery pressure) (19) 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 (43) 6V-3989 Unvalved nipple (44) 6V-4143 Coupler assembly (45) 6V-3014 Hose

Illustration 4	g00352235
Circuit diagram (1) Swing motor (2) Connector (3) Tee (4) Makeup line (5) Main control valves (6) Negative flow control line (upper pump) (7) 6V-9512 Plug (8) 6V-9508 Plug (9) 8T-0861 Pressure gauge (10) Pressure tap (upper pump delivery pressure) (11) 4C-9910 Portable hydraulic tester (flow meter) (12) Delivery line for lower pump (13) Delivery line for upper pump (14) 8T-0856 Pressure gauge (15) Pressure tap (power shift pressure) (16) Upper pump (17) Negative flow control line (lower pump) (18) Pressure tap (lower pump delivery pressure) (19) Lower pump (20) Multitach (21) Engine

Illustration 5	g00374904
Swing motor (1) Swing motor (2) Connector (4) Makeup line

Illustration 6	g00352233
Portable hydraulic tester (flow meter) (11) Portable hydraulic tester (flow meter) (20) Multitach (22) Valve

Illustration 7	g00375133
Pump compartment (6) Negative flow control line (upper pump) (10) Pressure tap (upper pump delivery pressure) (13) Delivery line (upper pump) (15) Pressure tap (power shift pressure) (16) Upper pump (18) Pressure tap (lower pump delivery pressure) (19) Lower pump

Preparation

Upper 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 flow meter tool layout and the circuit diagram. Refer to Illustration 3 and Illustration 4.

   1. Disconnect delivery line (13) from upper pump (16) .

   2. Install seal (30) and plug (7) to the end of delivery line (13) .

   3. Disconnect makeup line (4) from connector (2) at swing motor (1) .

   4. Install seal (30) and tee (3) to connector (2) .

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

   6. Connect portable hydraulic tester (11) between upper pump (16) and makeup line (4) .

   7. Connect 6000 kPa (870 psi) pressure gauge (14) to pressure tap (15). This is used to measure power shift pressure.

   8. Connect 60000 kPa (8700 psi) pressure gauge (9) to pressure tap (10). This is used to measure upper pump delivery pressure.

   9. Install multitach group (20) on engine (21). This is used to monitor engine speed.

   10. Disconnect negative flow control line (6) from upper pump (16). Install seal (42) and plug (8) to the end of negative flow control line (6) .

Lower Pump

Illustration 8	g00375134
Pump compartment (10) Pressure tap (upper pump delivery pressure) (12) Delivery line (lower pump) (15) Pressure tap (power shift pressure) (16) Upper pump (17) Negative flow control line (lower pump) (18) Pressure tap (lower pump delivery pressure) (19) 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 flow meter tool layout and the circuit diagram. Refer to Illustration 3 and Illustration 4.

   1. Disconnect delivery line (12) from lower pump (19) .

   2. Install plug (7) and seal (30) to the end of delivery line (12) .

   3. Disconnect makeup line (4) from connector (2) at swing motor (1) .

   4. Install seal (30) and tee (3) to connector (2) .

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

   6. Connect portable hydraulic tester (11) between lower pump (19) and makeup line (4) .

   7. Connect 6000 kPa (870 psi) pressure gauge (14) to pressure tap (15). This is used to measure power shift pressure.

   8. Connect 60000 kPa (8700 psi) pressure gauge (9) to pressure tap (18). This is used to measure lower pump delivery pressure.

   9. Install multitach group (20) to engine (21). This is used to monitor engine speed.

   10. Disconnect negative flow control line (17) from lower pump (19). Install seal (42) and plug (8) to the end of negative flow control line (17) .

Test

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

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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.

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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).

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Illustration 9	g00301843
Operator monitor panel (right console) (1) Controller display (2) Button for boom priority mode (3) Button for swing priority mode (4) Button for fine control mode (5) Button for user mode (6) Travel alarm cancel switch (7) Power mode switch

4. Start Service Mode and maintain power shift pressure at 2850 ± 50 kPa (415 ± 7 psi).

   1. Depress the following three buttons on the operator monitor panel at the same time: button for fine control (4), button for user mode (5) and travel alarm cancel switch (6). Hold all three buttons down for at least three seconds.

   2. The controller display (1) will be "00 00 00".

   3. Input the service code "0E 32 3A". To increase the flashing character, push the button for boom priority mode (2). To decrease the flashing character, push the button for swing priority mode (3). To move the flashing character to the right, push the button for fine control mode (4). To move the flashing character to the left, push the button for user mode (5) .

   4. Once the service code is entered into the controller display (1), depress the following three buttons on the operator monitor panel at the same time: button for fine control (4), button for user mode (5) and travel alarm cancel switch. Hold all three buttons down for at least three seconds.

   5. The controller display (1) will change to "10 -- 1".

      Note: If more than ten seconds pass between pushing the buttons, the controller display (1) will revert to the operation mode.

   6. On the operator monitor panel, enter a fixed power shift pressure of 2850 ± 50 kPa (415 ± 7 psi) on the controller display (1). Adjust controller display (1) in order to attain a power shift pressure of 2850 ± 50 kPa (415 ± 7 psi) on the pressure gauge at pressure tap (17) .

   7. Move the flashing character to the far left. Increase the "1" to a "6".

   8. Move the flashing character to the right and increase the "0" to a "6".

   9. The last four characters on the controller display (1) will begin flashing. These characters represent the power shift pressure (kPa). Adjust the last four characters to "2850". To increase the power shift pressure 10 kPa (1.5 psi), push the button for boom priority mode (2). To decrease the power shift pressure 10 kPa (1.5 psi), push the button for swing priority mode (3). To increase the power shift pressure 200 kPa (29 psi), push the button for boom priority mode (2) and power mode switch (7) at the same time. To decrease the power shift pressure 200 kPa (29 psi), push the button for swing priority mode (3) and power mode switch (7) at the same time.

      Note: Always monitor the actual power shift pressure on pressure gauge (14) at pressure tap (15). The actual power shift pressure must be 2850 ± 50 kPa (415 ± 7 psi) on the pressure gauge.

      Note: To prevent a change in power shift pressure during line relief valve adjustment, do not turn the engine OFF.

5. Maintain either one of the main pump pressures at 4900 kPa (700 psi) and keep the other pump without load.

6. Turn valve (22) on portable hydraulic tester (11) clockwise. Record pump flow at each of the following pressures in Table 1. Use pressure gauge (9) at pressure tap (10) to monitor upper pump delivery pressure or use pressure tap (18) to monitor lower pump delivery pressure.

Illustration 10	g00375136
P-Q characteristic curve

Note: Specifications for flow rates are based on an engine speed of 1950 rpm. To attain more accurate test results, measured flow should be corrected with the following calculation.

Note: Flow measurements must be done only during pressure rise.

Note: The pump flow changes approximately 10 L/min (2.6 US gpm) for each 100 kPa (14 psi) of power shift pressure.