311B and 312B Excavators Hydraulic System Caterpillar

Illustration 1	g00382192
Flow meter tool layout (1) Swing motor (2) Connector at swing motor (3) Tee (7) Delivery line for blade pump (8) Plug (9) 4C-9910 Portable hydraulic tester (flow meter) (10) 8T-0861 Pressure gauge (11) Pressure tap (blade pump delivery pressure) (14) Blade pump (16) 6V-3014 Hose (20) 6V-3989 Unvalved nipple (21) 6V-4143 Coupler assembly (23) O-Ring seal (24) Adapter (25) O-Ring seal (26) Nipple (27) Coupler (28) Coupling (29) Sleeve (30) Hose (31) Elbow (32) O-Ring seal (33) O-Ring seal

Illustration 2	g00382217
Circuit diagram (1) Swing motor (2) Connector (3) Tee (4) Makeup line (5) Main control valves (6) Blade control valve (7) Delivery line for blade pump (8) Plug (9) Portable hydraulic tester (flow meter) (10) Pressure gauge (11) Pressure tap (12) Engine (13) Multitach (14) Blade pump

Illustration 3	g00382219
Blade pump (7) Delivery line for blade pump (11) Pressure tap (blade pump delivery pressure)

Illustration 4	g00382453
(1) Swing motor (2) Connector (4) Makeup line

Illustration 5	g00382492
Portable hydraulic tester (flow meter) (9) Portable hydraulic tester (flow meter) (13) Multitach (15) Valve

Preparation

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 1 and Illustration 2.

   1. Disconnect delivery line (7) from blade pump (14).

   2. Install plug (8) and seal (33) to the end of delivery line (7).

   3. Disconnect makeup line (4) from connector (2) at 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 (9) between blade pump (14) and tee (3).

   7. Install multitach group (13) on engine (12). This is used to monitor engine speed.

   8. Connect 60000 kPa (8700 psi) pressure gauge (10) to pressure tap (11) of blade pump (14).

Test

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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).

4. Turn valve (15) on portable hydraulic tester (9) clockwise until the pump delivery pressure is 20600 ± 490 kPa (3000 ± 72 psi).

5. Record the pump flow in Table 1.

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

Flow measurements must be done in pressure rise.