322C Forest Machine Hydraulic System Pump Control (Negative Flow) - Test Caterpillar

This test measures individual pump flow at the pump while a fixed negative flow control pressure is sent to the main pump regulator. Each pump is tested individually for an output flow rate at a specified delivery pressure and a specified negative flow control pressure.

Illustration 1	g00670489
Flow meter tool layout (1) Swing motor (2) Connector at swing motor (3) 6V-9840 Swivel tee (4) Makeup Line (swing motor) (6) Negative flow control line (right pump) (10) 4C-9910 Portable hydraulic tester (flow meter) (11) Delivery line (left pump) (12) Delivery line (right pump) (13) Negative flow control line (left pump) (17) 9U-7335 Blocking cover (23) Right pump (24) Left pump (29) 1U-8303 Fitting (30) 5K-9090 O-Ring seal (31) 5P-0201 Hose (32) 5P-1010 Sleeve (33) 4C-8767 Coupling (34) 7M-8485 O-Ring seal (35) 4C-6481 Coupler assembly (36) 4C-6482 Nipple assembly (37) 4I-6141 Coupling (38) 8C-9026 Adapter (39) 6K-6307 O-Ring seal (40) 6V-9854 Swivel elbow (42) 1P-3703 Rectangular seal (46) 8T-4184 Bolt (47) 8T-4223 Hard washer (48) 6V-0400 Half flange (49) 1U-8292 Adapter

Illustration 2	g00817706
Circuit diagram (1) Swing motor (2) Connector (3) Tee (4) Makeup line (5) Main control valves (6) Negative flow control line (right pump) (7) Plug (8) Pressure tap (left pump delivery pressure) (9) Pressure gauge (10) Portable hydraulic tester (flow meter) (11) Delivery line (left pump) (12) Delivery line (right pump) (13) Negative flow control line (left pump) (14) Pressure tap (power shift pressure) (15) Tees (16) Pressure tap (right pump delivery pressure) (17) Blocking cover (18) Test line (20) Pressure gauge (21) Engine (22) Multitach group (23) Right pump (24) Left pump (40) Elbow

Right Pump

Note: Perform the test for the right pump and the test for the left pump one at a time.

Illustration 3	g00817722
Pump compartment (6) Negative flow control line (right pump) (12) Delivery line (right pump) (16) Pressure tap (right pump delivery pressure) (23) Right pump (24) Left 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 2.

   1. Disconnect delivery line (12) from right pump (23) .

   2. Install seal (42), half flanges (48) and blocking cover (17) to the end of delivery line (12) with bolts (46) and washers (47) .

   3. Assemble and install seal (42), adapter (49), half flanges (48), seals (34), fitting (29) and nipple assembly (36) on right pump (23) with bolts (46) and washers (47) .
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   Illustration 4	g00669270
   Swing motor (top view) (1) Swing motor (2) Connector (3) Tee (4) Makeup line (40) Elbow

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

   5. Assemble and install seals (30), tee (3), swivel elbow (40) and coupling (37) to connector (2) at swing motor (1) .

   6. Install seal (30) and makeup line (4) to tee (3) .

   7. Connect flow meter (10) and the test hoses between nipple assembly (36) at right pump (23) and coupling (37) at the swing motor.

   8. Connect 49000 kPa (7100 psi) pressure gauge (9) to pressure tap (16) for right pump delivery pressure.

   9. Install multitach group (22) on engine (21). This is used to monitor engine speed.
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   Illustration 5	g00670945
   Tool setup (6) Negative flow control line (right pump) (7) 6V-9508 Face seal plug (13) Negative flow control line (left pump) (14) Pressure tap (power shift pressure) (15) 8T-8902 Tee (18) 177-7860 Hose assembly (19) Left pump regulator (20) 8T-0855 Pressure gauge (23) Right pump (24) Left pump (25) 6V-8397 O-Ring seal (27) 6V-9829 Cap (28) 3J-1907 O-Ring seal (41) 6V-3965 Fitting (43) 6V-4143 Coupler (44) Test hose (45) 6V-3989 Fitting

   10. Disconnect negative flow control line (6) from right pump (23). Install seal (25) and plug (7) to the end of negative flow control line (6) .

   11. Connect two tees (15) to the elbow at the negative flow signal pressure port of right pump (23). Install cap (27) to tee (15) .

   12. Connect one end of test hose (18) to tee (15) .

   13. Connect the other end of test hose (18) to pressure tap (14) for the power shift pressure.

   14. Connect one end of test hose (44) to tee (15) .

   15. Connect 4900 kPa (700 psi) pressure gauge (20) to the other end of test hose (44) .

Left Pump

Note: Perform the test for the right pump and the test for the left pump one at a time.

Illustration 6	g00817737
Pump compartment (8) Pressure tap (left pump delivery pressure) (11) Delivery line (left pump) (13) Negative flow control line (left pump) (23) Right pump (24) Left 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 2.

   1. Disconnect delivery line (11) from left pump (24) .

   2. Install seal (42), half flanges (48) and blocking cover (17) to the end of delivery line (11) with bolts (46) and washers (47) .

   3. Assemble and install seal (42), adapter (49), seals (34), fitting (29) and nipple assembly (36) to left pump (24) with half flanges (48), bolts (46) and washers (47) .
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   Illustration 7	g00669270
   Swing motor (top view) (1) Swing motor (2) Connector (3) Tee (4) Makeup line (40) Elbow

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

   5. Assemble and install seals (30), tee (3), swivel elbow (40) and coupling (37) to connector (2) at swing motor (1) .

   6. Install seal (30) and makeup line (4) to tee (3) .

   7. Connect flow meter (10) and the test hoses between nipple assembly (36) at left pump (24) and coupling (37) at the swing motor.

   8. Connect 49000 kPa (7100 psi) pressure gauge (9) to pressure tap (8) for left pump delivery pressure.

   9. Install multitach group (22) on engine (21). This is used to monitor engine speed.
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   Illustration 8	g00670945
   Tool setup (6) Negative flow control line (right pump) (7) 6V-9508 Face seal plug (13) Negative flow control line (left pump) (14) Pressure tap (power shift pressure) (15) 8T-8902 Tee (18) 177-7860 Hose assembly (19) Left pump regulator (20) 8T-0855 Pressure gauge (23) Right pump (24) Left pump (25) 6V-8397 O-Ring seal (27) 6V-9829 Cap (28) 3J-1907 O-Ring seal (41) 6V-3965 Fitting (43) 6V-4143 Coupler (44) Test hose (45) 6V-3989 Fitting

   10. Disconnect negative flow control line (13) from left pump (24). Install seal (25) and plug (7) to the end of negative flow control line (13) .

   11. Connect two tees (15) to the elbow at the negative flow signal pressure port of left pump (24). Install cap (27) to tee (15) .

   12. Connect one end of test hose (18) to tee (15) .

   13. Connect the other end of test hose (18) to pressure tap (14) for the power shift pressure.

   14. Connect one end of test hose (44) to tee (15) .

   15. Connect 4900 kPa (700 psi) pressure gauge (20) to the other end of test hose (44) .

Test

Note: Perform the test for the right pump and the test for the left 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: engine speed dial "10" and AEC switch OFF. Refer to Testing and Adjusting, "Engine Performance - Test (Engine Speed)" for engine rpm settings.

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

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Illustration 9	g00672009
Monitor (A) Message display (B) Keypad (C) Up key (D) Left key (E) Down key (F) Right key (G) Cancel key (H) Set key (I) OK key (J) Menu key

4. Start Service Mode and input a fixed power shift pressure of 2550 kPa (370 psi).

   1. Press menu key (J) .

      Note: If more than thirty seconds pass between pushing the keys on the keypad, the menu mode will be cancelled and the previous display will be restored to message display (A) .

   2. Press down key (E) in order to highlight the second menu item "SERVICE OPTIONS" on the message display. Press OK key (I) .

   3. Input the password "FFF2". Press left key (D) or right key (F) in order to change the position of the flashing character. Press up key (C) or press down key (E) in order to change the value of the flashing character. Press OK key (I) after the correct password is displayed.

   4. Press down key (E) once in order to highlight the second line on the message display.

   5. Press right key (F) repeatedly until "DEVICE TEST" appears on the message display.

   6. Press down key (E) in order to move down one line on the message display.

   7. Press right key (F) until the "PS PRV - FIXED" appears on the message display.

   8. Press down key (E) .

   9. Press OK key (I). The display on line 4 of the message display will now change to a numeric value. These characters represent the power shift pressure (kPa).

   10. Press left key (D) or right key (F) in order to increase or decrease the numeric value that is displayed on line 4 of the message display. Pressing left key (D) decreases the power shift pressure. Pressing right key (F) increases the power shift pressure.

       Note: The value for power shift pressure on the monitor may not always match the pressure reading on the pressure gauge. Adjust the value on the monitor until the desired power shift pressure is attained on the pressure gauge that is connected to the pressure tap for power shift pressure. The actual power shift pressure must be 2550 kPa (370 psi) on the pressure gauge.

       Note: To prevent a change in power shift pressure during the pump flow test, do not turn the engine start switch to the OFF position.

       Note: Refer to Service Manual, "Engine and Pump Electronic Control System" for additional information on Service Mode.

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Illustration 10	g00670500
(10) Portable hydraulic tester (flow meter) (22) Multitach (26) Valve

5. Turn valve (26) on flow meter (10) clockwise until the pump delivery pressure is 6850 kPa (1000 psi).

6. Record the negative flow rate in Table 1.

Illustration 11	g00778431
Pressure/Flow 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.