312F and 313F Excavator Machine Systems Pump Control (Negative Flow)

Table 1
"Pump Control (Negative Flow) - Test"
Measured Items		Measuring Points
Machine Settings	Engine Speed	Engine speed dial "10" AEC switch OFF
	Pump Pressure	No Load Standby Pressure
	Pump Flow Limit Pressure	3000 kPa (435 psi)⁽¹⁾
Drive Pump Flow Measured L/min (US gpm)
Engine Speed (rpm)
Oil Temperature °C (°F)
Idler Pump Flow Measured L/min (US gpm)
Engine Speed (rpm)
Oil Temperature °C (°F)
Specification for negative flow rate L/min (US gpm)		40 ± 10 L/min (10.6 ± 2.6 US gpm)

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⁽¹⁾	Negative Flow Control Adjustment

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Illustration 1	g06016434
Pressure/Flow characteristic curve

Note: Specifications for flow rates are based on an engine speed of 1500 rpm. To get more accurate test results, measured flow should be corrected with the following calculation.

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Table 2
Corrected flow	=	Measured flow x 1500 rpm
		Measured rpm

Flow measurements must be done only during pressure rise.

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.

The following procedures must be completed before performing the test procedure.

Set the pilot pressure to the specifications in Testing and Adjusting, "Relief Valve (Pilot) - Test and Adjust" for the machine.
Calibrate the power shift pressure. Refer to Testing and Adjusting, "Solenoid Valve (Proportional Reducing) - Calibrate (Power Shift Pressure)" for the machine.

Required Tools

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Illustration 2	g02571852
Tooling (A) 198-4240 Digital Pressure Indicator Gp

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Illustration 3	g02535237
Tooling (C)

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Illustration 4	g02793286
Tooling (D) (Flow meter tool layout)

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Illustration 5	g03324637
Tooling (E)

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Table 3
Required Tools
Tool	Item	Qty	Part Number	Description
A			198-4240	Digital Pressure Indicator Gp
	A1	1	198-4234	Indicator
	A2	1	198-4237	Pressure Sensor 3447 kPa (500 psi)
	A2	2	198-4239	Pressure Sensor 41,368 kPa (6,000 psi)
	A3	3	198-4236	Extension Cable
C			348-5430	Multi-Tool Gp
	C1	1	285-0908	Multi-Tool
	C2	1	6V-2198	Cable As
	C3	1	9U-5140	Photo Pickup
	C4	1	6V-3137	Base
	C5	1	1U-6605	Reflective Tape
	C6	1	6V-3138	Extension
D	D1	1	4C-9910	Portable hydraulic tester (flow meter)
	D2	2	6K-6307	O-Ring Seal
	D3	2	8C-9026	Adapter
	D4	8	7M-8485	O-Ring Seal
	D5	4	4C-6482	Fitting
	D6	4	4C-6481	Coupler
	D7	4	4C-8767	Coupling
	D8	4	5P-1010	Sleeve
	D9	2	5P-0201	Hose
	D10	2	4I-6140	Adapter
	D11	1	6V-9511	Plug
	D12	1	6V-9853	Elbow
	D14	4	6V-9746	O-Ring Seal
	D15	1	6V-9839	Swivel Tee
E	E1	3	6V-8397	O-Ring Seal
	E2	1	6V-9508	Plug
	E3	2	8T-8902	Swivel Tee
	E4	2	3J-1907	O-Ring Seal
	E5	2	6V-3989	Fitting
	E6	1	6V-9829	Cap
	E7	2	6V-4143	Coupler
	E8	1	177-7860	Hose
F		1	311-1362	Vacuum Cap

Reference: Refer to Tool Operating Manual, NEHS1087 for operating instructions for the 348-5430 Multi-Tool Gp.

Note: Use Software License Card, NETG5049 with part number 348-5430 Multi-Tool Gp.

Machine Preparation

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NOTICE

Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting, and repair of the product. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids. Refer to Special Publication, NENG2500, "Dealer Service Tool Catalog" for tools and supplies suitable to collect and contain fluids on Cat^® products. Dispose of all fluids according to local regulations and mandates.

Note: Perform the test for the drive pump and the test for the idler pump one at a time.

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Illustration 6	g03324515
Flow meter tool layout Tooling (D) ( 4) Delivery line for drive pump (5) Delivery line for idler pump (8) Seal (9) Makeup line (10) Seal (11) Elbow

Position the machine on level ground.
Stop the engine.
Release pressure in the hydraulic system. Refer to Testing and Adjusting, "System Pressure - Release".
Attach 311-1362 Vacuum Cap onto the hydraulic tank. Attach an air supply hose onto the assembly. Apply 276 to 414 kPa (40 to 60 psi). This procedure will pull a vacuum on the hydraulic system.

Drive Pump

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Illustration 7	g02788589
Pump compartment (1) Pressure tap (delivery pressure for drive pump) (2) Pressure tap (delivery pressure for idler pump) (3) Pressure tap (power shift pressure) (4) Delivery line for drive pump (5) Delivery line for idler pump (6) Negative flow control line (drive pump) (7) Negative flow control line (idler pump)

Disconnect delivery line (4) from the drive pump.
Install seal (8) and plug (D11) to the end of the delivery line.
Assemble and install seals (D14), elbow (D12), adapter (D10), seal (D4), and fitting (D5) on the drive pump.
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Illustration 8 g03324497

Swing motor
(9) Makeup line
(10) Seal
(11) Elbow
Disconnect makeup line (9) from elbow (11) at the swing motor.
Assemble and install seals (D14), tee (D15), adapter (D10), seal (D4), and fitting (D5) to elbow (11) at the swing motor.
Connect seal (10) and makeup line (9) to tee (D15).

Connect portable hydraulic tester (D) and test hoses between coupling assembly at the drive pump and coupling assembly at the swing motor.

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Illustration 9	g03323137
Pump compartment Tooling (E) ( 3) Pressure tap (power shift pressure) (4) Delivery line for drive pump (5) Delivery line for idler pump (6) Negative flow control line (drive pump) (7) Negative flow control line (idler pump) (12) Connector (13) Seal

Disconnect negative flow control line (6) from connector (12) and install plug (E2) and seal (13).
Install Tooling (E) between connector (12) and pressure tap (3).
Attach a 3447 kPa (500 psi) pressure sensor (A2) to pressure tap (E5) to monitor negative flow control pressure for the drive pump.
Remove 311-1362 Vacuum Cap and install the filler plug for the hydraulic tank.
Attach a 41,368 kPa (6,000 psi) pressure sensor to pressure tap (1) for delivery pressure of the drive pump.
Install multi-tool group (C) on the engine to monitor engine speed.

Idler Pump

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Illustration 10	g02788589
Pump compartment (1) Pressure tap (delivery pressure for drive pump) (2) Pressure tap (delivery pressure for idler pump) (3) Pressure tap (power shift pressure) (4) Delivery line for drive pump (5) Delivery line for idler pump (6) Negative flow control line (drive pump) (7) Negative flow control line (idler pump)

Disconnect delivery line (5) from the idler pump.
Install seal (8) and plug (D11) to the end of the delivery line.
Assemble and install seals (D14), elbow (D12), adapter (D10), seal (D4), and fitting (D5) on the idler pump.
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Illustration 11 g03324497

Swing motor
(9) Makeup line
(10) Seal
(11) Elbow
Disconnect makeup line (9) from elbow (11) at the swing motor.
Assemble and install seals (D14), tee (D15), adapter (D10), seal (D4), and fitting (D5) to elbow (11) at the swing motor.
Connect seal (10) and makeup line (9) to tee (D15).

Connect portable hydraulic tester (D) and test hoses between coupling assembly at the idler pump and coupling assembly at the swing motor.

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Illustration 12	g03324788
Pump compartment Tooling (E) ( 3) Pressure tap (power shift pressure) (4) Delivery line for drive pump (5) Delivery line for idler pump (6) Negative flow control line (drive pump) (7) Negative flow control line (idler pump) (12) Connector (13) Seal

Disconnect negative flow control line (7) from connector (14) and install plug (E2) and seal (13).
Install Tooling (E) between connector (14) and pressure tap (3).
Attach a 3447 kPa (500 psi) pressure sensor (A2) to pressure tap (E5) to monitor negative flow control pressure for the idler pump.
Remove 311-1362 Vacuum Cap and install the filler plug for the hydraulic tank.
Attach a 41,368 kPa (6,000 psi) pressure sensor to pressure tap (2) for delivery pressure of the idler pump.
Install multi-tool group (C) on the engine to monitor engine speed.

Test Procedure

Note: Perform the test for the drive pump and the test for the idler 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.

Start the engine.
Increase the hydraulic oil temperature to 55° ± 5°C (131° ± 9°F).
Enter the service mode.
1. Input the password "9992".
2. Select "Override Parameters".
3. Set the engine speed to 1500 rpm.
4. Set the "Power Shift Pressure" to 3000 kPa (435 psi). Confirm the power shift pressure at pressure tap (E5).
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Illustration 13 g02599896

Portable hydraulic tester (flow meter)
(D1) Portable hydraulic tester (flow meter)
(17) Valve
Turn valve (17) on the portable hydraulic tester clockwise. The measuring point is listed in Table 1. Use the pressure sensor at pressure tap (1) to monitor the delivery pressure of the drive pump. Use pressure tap (2) to monitor the delivery pressure of the idler pump.
Note: To perform flow measurements for either one of the pumps, the other pump must not be under load.