OPERATIONAL PERFORMANCE TEST / Component Test MAIN PUMP FLOW RATE MEASUREMENT P-Q Control (Torque Control) Summary: Main pump performance is checked by measuring the pump flow rate by using a hydraulic tester in- stalled at the main pump delivery port (one side) to be measured. Use Dr. ZX and a pressure gauge at the same time. IMPORTANT: This measurement procedure is a simple method. The measured data will be lower by approx. 5 % than the accurately measured value. In order to measure accurately, disconnect the return circuit from the control valve and connect it to the hydraulic oil tank. Preparation: 1. Stop the engine. Push the air bleed valve and bleed air.
Install a vacuum pump to the oil filler port. 5. Install a pressure gauge to the main pump to be measured. (Refer to “Main Relief Set Pressure”.) : 6 mm 6. Remove pipe (13) from the regulator. Install plug (G 1/4) to pipe (13) in the regulator. : 17 mm 7. Remove the vacuum pump. Loosen plug (12) on top of the pump casing. Bleed air from the casing until oil only comes out. 8. Fully open the loading valve of hydraulic tester. 9. Start the engine. Check the pressure gauge con- nection for any oil leaks. Install Dr. ZX and select the monitoring function. Measurement: 1. Maintain the hydraulic oil temperature at 50 ± 5 ° C (122 ± 41 ° F). 2. Measure the maximum flow rate. 3.
Select each switch position as follows: NOTE: Operate the vacuum pump while connect- ing the pump flow rate test line. 2. Remove the delivery hose from main pump (one side) to be measured. Install pipe (1 or 2) by using the split flanges and bolts which were used for the removed delivery hose. 4. Adjust the relief set pressure of main relief valve in control valve to each pressure point specified along the main pump P-Q curve. (Refer to T4-2-13) Slowly restrict the loading valve of hy- draulic tester while relieving pressure in the arm roll-in circuit. Measure the flow rates and engine speeds at each pressure point specified in the P-Q curve. 5.
Repeat each measurement three times and cal- culate the average values. : 10 mm 3. Install pipe (1 or 2) to hydraulic tester (5) by using test hose (3) and adapter (4). Install adapter (6), joint (7), test hose (8) and flange (9) to hydraulic tester (5). : 41 mm : 41 mm : 10 mm 4. Install the delivery hose to flange (9) with split flanges (10) and bolt (11). : 10 mm T4-5-18 Engine Control Dial Power Mode Switch Auto-Idle Switch Work Mode Fast Idle P Mode OFF Digging Mode