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TESTING AND ADJUSTING

INSPECTION AND ADJUSTMENT OF PUMP PC CONTROL CIRCUIT OIL PRESSURE

4) Measure the hydraulic oil pressure with all the control levers kept in the NEUTRAL position and the engine running at high idle and at low idle. If PC-EPC valve output pressure changes to the following values, it is judged normal. Engine speed

Low idle High idle

Control lever Neutral

Hydraulic oil pressure 2.9 MPa {30 kg/cm2} 0 MPa {0 kg/cm2}

Adjustment If any of the phenomena mentioned below occurs and PC valve malfunctioning is suspected, adjust PC valves (6) and (7) in the following manner. • As workload increases, the engine speed sharply drops. • While the engine speed is normal, the work equipment moves slowly. • (6): Front pump PC valve • (7): Rear pump PC valve The width across flats of the locknut for the PC valve is 13 mm and that of the adjustment screw (inside width) is 4 mm. Do not turn any other locknut or adjustment screw since it has effects on the performance of the hydraulic pumps.

2. Turn adjustment screw (9) to the right or left to adjust. Turn the adjustment screw in the following directions. • In the work equipment speed is low, turn the adjustment screw to the right (to increase the pump absorption torque). • If the engine speed lowers, turn the adjustment screw to the left (to decrease the pump absorption torque). 3. Tighten lock nut (8). Lock nut: 27.50 – 34.3 Nm {2.8–3.5 kgm}

4. Confirm that the PC valve output pressure (servo piston inlet pressure) is normal after the adjustment, following the measurement steps explained earlier.

1. Loosen lock nut (8). Before loosening the lock nut, make match marks at the adjustment screw end so that you can see the position of the lock nut before the adjustment (and you can return the lock nut to its original position after turning it in reverse).

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PC300/350(LC)-7

TESTING AND ADJUSTING

INSPECTION AND ADJUSTMENT OF PUMP LS CONTROL CIRCUIT OIL PRESSURE

INSPECTION AND ADJUSTMENT OF PUMP LS CONTROL CIRCUIT OIL PRESSURE Pump LS control circuit oil pressure inspection and adjustment tools

Mark 1 M

2 3

Part No. 799-101-5002 790-261-1204 799-101-5220 07002-11023

799-401-2701

•

Part name Hydraulic tester Digital type hydraulic tester Nipple (10 x 1.25 mm) O-ring Differential pressure gauge

Measurement Measure pump LS control circuit oil pressure after confirming that the work equipment, swing and travel circuit oil pressure as well as control circuit original pressure are normal. Lower the work equipment to the ground and stop the engine. After the engine stops, operate the control lever several times to release the remaining pressure in the piping. Then loosen the oil filler cap to release the pressure inside the hydraulic tank. 1. Measurement of LS valve output pressure (servo piston inlet pressure) Measure LS valve output pressure (servo piston inlet pressure) and pump delivery pressure together, and compare both pressures thereafter. 1) Remove oil pressure measurement plugs (1), (2), (3) and (4). • Plug (1): For measuring the front pump delivery pressure (at the machine rear part) • Plug (2): For measuring the rear pump delivery pressure (at the machine front part)

PC300/350(LC)-7

•

Plug (3): For measuring the front pump LS valve delivery pressure Plug (4): For measuring the rear pump LS valve delivery pressure

2) Fit nipple M2 and connect it to oil pressure gauge [1] of hydraulic tester M1. Use an oil pressure gauge with the capacity of 58.8 MPa {600 kg/cm2}. •

Photo shows pump delivery pressure side.

•

Photo shows LS valve output pressure side.

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TESTING AND ADJUSTING

INSPECTION AND ADJUSTMENT OF PUMP LS CONTROL CIRCUIT OIL PRESSURE

3) Run the engine and raise the hydraulic oil temperature to the operating range and push up the track shoe on the side to be measured with the work equipment. • For measuring oil pressure in front circuit: Right track shoe • For measuring oil pressure in rear circuit: Left track shoe Provide a working area of sufficient space, as the raised track shoe will be idly rotated.

4) Measure pump delivery pressure and PC valve output pressure (servo piston inlet pressure) together with the machine set at the following conditions and the engine running at high idle. • Working mode: A mode • All the control levers of the work equipment, swing and travel are kept in the NEUTRAL position and the travel control lever is kept at half stroke (one side of the track shoes idly rotates). Let the raised track shoe idly rotate, paying enough attention to the surroundings for safety. Judgement method: When the ratio between the pump delivery pressure and LS valve output pressure (servo piston output pressure) reaches the following values, both pressures are judged normal.

Oil pressure ratio Oil pressure to be All control levers Travel at half measured in NEUTRAL stroke Pump delivery 1 pressure Nearly equal pressure LS valve delivery Approx. 0.6 pressure

5) Detach all the measurement tools after the me asuremen t an d m ake sure that the machine is back to normal condition.

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2.

Measurement of LS differential pressure LS differential pressure can be obtained by measuring pump delivery pressure and LS pressure (actuator loaded pressure) at the same time and computing the difference of both pressures. 1) Remove oil pressure measurement plugs (1), (2), (5) and (6). • Plug (1): For measuring the front pump delivery pressure (at the machine rear part) • Plug (2): For measuring the rear pump delivery pressure (at the machine front part)

• •

Plug (5): For measuring the front pump LS pressure (at the machine rear part) Plug (6): For measuring the rear pump LS pressure (at the machine rear part)

2) Fit nipple M2 and connect it to oil pressure gauge [1] of hydraulic tester M1 or differential pressure gauge M3. When using a differential pressure gauge: Connect pump delivery pressure to the high pressure side and LS pressure to the low pressure side. A differential pressure gauge requires DC 12V power. Connect it with one battery. When using an oil pressure gauge: Use an oil pressure gauge with the capacity of 58.8 MPa{600 kg/cm 2}.

PC300/350(LC)-7

TESTING AND ADJUSTING

INSPECTION AND ADJUSTMENT OF PUMP LS CONTROL CIRCUIT OIL PRESSURE

The max. differential pressure is no more than approx. 3.9 MPa {40 kg/cm 2}. The same gauge may be used throughout the measurement. •

Photo shows pump delivery pressure side.

•

Photo shows LS pressure side.

4) Measure pump delivery pressure and LS pressure (actuator loaded pressure) together with the machine set at the following conditions and the engine running at high idle. • Working mode: A mode • Traveling speed: Hi • All the control levers of the work equipment, swing and travel are kept in the NEUTRAL position and the travel control lever is kept at half stroke (one side of the track shoes idly rotates). Let the raised track shoe idly rotate, paying enough attention to the surroundings for safety. Calculation of LS differential pressure: LS differential pressure = Pump delivery pressure – LS pressure If LS differential pressure is in the following conditions, it is judged normal.

Control lever position LS differential pressure All levers in Unload pressure NEUTRAL (see standard value table) Travel lever at half Max. LS differential pressure stroke (Run track idle) (see standard value table)

5) Detach all the measurement tools after the measurement, and make sure that the machine is back to normal condition. 3. 3) Run the engine and raise the hydraulic oil temperature to the operating range and push up the track shoe on the side to be measured with the work equipment. • For measuring oil pressure in front circuit: Left track shoe • For measuring oil pressure in rear circuit: Right track shoe Provide a working area of sufficient space, as the raised track shoe will be idly rotated.

PC300/350(LC)-7

Measurement of LS-EPC valve output pressure 1) Remove oil pressure measurement plug (7). The plug is fitted on the rear pump.

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TESTING AND ADJUSTING

INSPECTION AND ADJUSTMENT OF PUMP LS CONTROL CIRCUIT OIL PRESSURE

2) Fit nipple M2 and connect it with oil pressure gauge [1] of hydraulic tester M1. Use an oil pressure gauge with the capacity of 5.9 MPa {60 kg/cm2}.

3) Start the engine and keep it running until the hydraulic oil temperature rises to the operating range.

Adjustment When LS differential pressure is not normal, adjust it with LS valves (8) and (9). • (8): Front pump LS valve • (9): Rear pump LS valve

1. Fix adjusting screw (11) and loosen lock nut (10). 2. Adjust the pressure by turning adjusting screw (11). If the adjusting screw is turned to the right, the differential pressure rises. If the adjusting screw is turned to the left, the differential pressure falls. Adjustment amount (LS differential pressure) per turn of adjusting screw: 1.3 MPa {13.3 kg/cm2} 3. Fix adjusting screw (11) and tighten lock nut (10). Lock nut: 49 – 64 Nm {5–7 kgm}

4) Measure the oil pressure when the engine is running at high idle and the travel speed switch and travel lever are operated. If LS-EPC valve output pressure changes to the following values, the pressure is normal.

Travel speed

Travel control lever

Hi

Fine control (Note)

Lo

Neutral

Hydraulic pressure Approx. 1.4 MPa {approx. 14 kg/cm2} 0 MPa {0 kg/cm2}

Note: Operate the travel control lever slightly to the extent that the PPC hydraulic oil pressure is turned ON. (Stop the operation short of starting the machine) 5) Detach all the measurement tools after the measurement, and make sure that the machine is back to normal condition.

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4. After the adjustment, confirm that LS differential pressure is normal, following the steps for measurement explained earlier.

PC300/350(LC)-7

TESTING AND ADJUSTING

MEASUREMENT OF SOLENOID VALVE OUTPUT PRESSURE

MEASUREMENT OF SOLENOID VALVE OUTPUT PRESSURE Solenoid valve output pressure measurement tools

Mark N

1 2 3

Part No. 799-101-5002 790-261-1204

799-401-3100 799-401-3200

Part name Hydraulic tester Digital type hydraulic tester Adapter (Size 02) Adapter (Size 03)

Measure solenoid valve output pressure after confirming that control circuit original pressure is normal. Lower the work equipment to the ground and stop the engine. After the engine stops, operate the control lever several times to release the remaining pressure in the piping. Then loosen the oil filler cap to release the pressure inside the hydraulic tank.

2.

Fix adapter N2 or N3 and connect the disconnected hose again.

3.

Fit nipple [1] of hydraulic tester N1 and connect it to oil pressure gauge [2]. Use an oil pressure gauge with the capacity of 5.9 MPa {60 kg/cm2}.

4.

Start the engine and keep it running until the hydraulic oil temperature rises to the operating range.

1. Disconnect the hoses of solenoid valve to be measured at the outlet side. No. 1 2 3 4 5 6 7

Solenoid valve to be measured PPC lock solenoid valve Travel interconnection solenoid valve Merge/divide solenoid valve Travel speed shifting solenoid valve Swing and parking brake solenoid valve Machine push-up solenoid valve 2-stage relief solenoid valve

Hose (1) is installed at the rear of operator's cab, and hoses (2) through (7) are installed at the center of revolving frame.

PC300/350(LC)-7

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TESTING AND ADJUSTING 5.

MEASUREMENT OF SOLENOID VALVE OUTPUT PRESSURE

Run the engine at full throttle, then turn each solenoid valve ON or OFF by operating the control lever switch, and measure the pressure. For conditions for turning each solenoid valve ON or OFF, refer to the ensuing "Table for Functioning Conditions" for each solenoid valve. How each solenoid valve functions can be confirmed with monitoring function in the monitor panel. (Special Function of Machine Monitor) When each output pressure shows the following values, it is judged normal.

Solenoid valve OFF (Demagnetization) ON (Excitation)

Output pressure

0 MPa {0 kg/cm2}

3 MPa {30 kg/cm2}

6. Detach all the measurement tools after the measurement, and make sure that the machine is back to normal condition. Table for Functioning conditions - PPC lock solenoid valve Functioning condition Locked Safety lock lever Released

Table for Functioning conditions - Machine push-up solenoid valve Functioning condition OFF ON

Machine push-up switch

Functioning OFF ON

Table for Functioning conditions - Swing and parking brake solenoid Functioning condition When all of them Work equipment, is OFF swing, travel, When any of signaling them is ON

Functioning condition When the travel steering signal is ON When the travel steering signal is OFF

(8)

OFF ON

Functioning ON OFF

Table for Functioning conditions - Travel interconnection solenoid valve

20-130

Functioning

If front or rear pump pressure is over 24.5 MPa {250 kg/cm 2} In conditions other than above Traveling operation only

Functioning ON ON

OFF

PC300/350(LC)-7

TESTING AND ADJUSTING

MEASUREMENT OF SOLENOID VALVE OUTPUT PRESSURE

Table for Functioning conditions - Travel speed shifting solenoid valve

Functioning condition When overheat setting of the 2nd stage is ON When the fuel dial indicates less than 1,200 rpm When the travel speed switch is at Lo (or Mi (*1)) The travel signal is OFF If front or rear pump pressure is When the travel speed switch is at Hi The travel 32.3 MPa {330 kg/cm2} signal is ON If front or rear pump pressure is 18.6 MPa {190 kg/cm2} In conditions other than above

Functioning

OFF

ON

*1: The "Mi" mode is on the multi-monitor specification machine only. Table for Functioning conditions - 2-stage relief solenoid valve

Functioning condition Functioning overheat setting of the 1st stage is ON OFF all the signals for work equipment, swing and travel are OFF swing lock switch is ON travel signal is ON working mode is L mode (*2) ON boom LOWER signal is ON When working mode is A or E When left knob If signals other than swing operation only is ON mode switch is ON If swing operation only is ON OFF In conditions other than above When When When When When When

Table for Functioning conditions - Merge/divide solenoid valve When working mode is B mode When travel signal only is ON

Functioning condition When service signal is ON

When F or R pump pressure is 2 Other than L 19.6 MPa {200 kg/cm } When F or R pump pressure is When the work mode 14.7 MPa {150 kg/cm2} When the travel equipment and signal is ON swing signals When F or R pump pressure is are ON 16.7 MPa {170 kg/cm2} L mode (*2) When F or R pump pressure is 11.8 MPa {120 kg/cm2} In conditions other than above

Functioning higher than lower than higher than lower than

ON OFF ON OFF

*2: The "L" mode is on the multi-monitor specification machine only.

PC300/350(LC)-7

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