BAR AS- 4719284 - Caterpillar

Checking Pump Efficiency
For any pump test at a given rpm, the pump flow (gpm) at 100 psi (7.0 kg/cm2) will be larger than the pump flow (gpm) at 1000 psi (70.3 kg/cm2).The difference between the pump flow of two operating pressures is the flow loss. Flow loss when expressed as a percent of flow loss is used as a measure of pump performance. If the percent of flow loss is more than 10% for test on the machine or 15% for test on the bench, pump performance is not good enough.*Numbers in examples are for illustration and are not values for any specific pump or pump condition. See STEERING AND BRAKE SYSTEM SPECIFICATIONS, Form No. REG01255, for pump flow of a new pump at 100 psi and 1000 psi.Test On The Machine
Install a 9S2000 Flow Meter. Measure pump flow at 100 psi (7.0 kg/cm2) and at 1000 psi (70.3 kg/cm2) with engine at 2000 rpm. See Tee Test Tooling Chart, Form Number REG00910-02. Test On The Bench
If the test bench can not be run at 1000 psi at a high rpm, do the first part of the test with the pump shaft rotation at 1100 rpm. Measure pump flow at 100 psi (7.0 kg/cm2) and at 1000 psi (70.3 kg/cm2). Then in order to measure the pump flow for the last part of the test, see STEERING AND BRAKE SYSTEM SPECIFICATIONS, Form No. REG01255, for: Pump rpm at 100 psi with the engine at 2000 rpm.
HYDRAULIC SYSTEM SCHEMATIC
1. Cap. 2. Supply tank for the power and master cylinder for the wheel brakes. 3. Oil lines to brake calipers. 4. Oil line from relief valve. 5. Flow control and relief valve. 6. Oil line from pump to flow control and relief valve. 7. Pump section for hydraulic loader system. 8. Oil line to loader control valve sections. 9. Pump section for steering and brake hydraulic systems. 10. Oil line from supply tank.Relief Valve
The relief valve is in flow control and relief valve (5). The pressure setting of the relief valve can be tested. An adjustment of the valve is needed if the relief pressure setting is not correct.
HYDRAULIC PUMP
7. Pump section for loader hydraulic system. 8. Oil line to loader control valve sections. 9. Pump section for the steering and brake hydraulic systems. 10. Oil line from supply tank.1. Stop the engine and loosen the filler cap on the hydraulic tank.2. Remove the plug in tube (6) which is near pump section (7) and install 5S4648 Hose Assembly in the plug opening in the tube. Install 1S8937 Valve and 7S8714 Pressure Gauge (0 to 4000 psi) in the other end of the hose assembly.3. Start the engine and run it at high idle speed. Turn the machine to the left and then to the right. Turn the machine against the stop either for a right or a left turn. Look at the pressure gauge and turn the steering wheel farther (and hold it it turned). The reading on the