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Hydraulic oil pressure can remain in the hydraulic system on this machine after the engine and pump have been stopped. Serious injury can result if this pressure is not released before any service is done on the hydraulic system. In order to prevent possible injury, release the hydraulic system pressure before working on any fitting, hose, or hydraulic component. Lower all work tools to the ground before service is started. If the hydraulic system must be serviced, tested, or adjusted with the work tool in the raised position, the work tool and lift cylinders must be supported properly. Always move the machine to a location away from the travel of other machines. Be sure that other personnel are not near the machine when the engine is running and tests or adjustments are being made. |
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Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting and repair of the machine. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids. Refer to Special Publication, NENG2500, "Caterpillar Tools and Shop Products Guide", for tools and supplies suitable to collect and contain fluids. Dispose of all fluids according to local regulations and mandates. |
This test is designed to determine if a pump is operating within the designed parameters.
Note: This test is performed on a test bench.
Tools are not required for this test procedure.
- Before taking any data, the oil 10W supply must be
82° ± 4°C (180° ± 10°F) . Set pump control for maximum displacement. - Record the output flow from the pump at
3450 kPa (500 psi) and 2000 rpm. - Record the output flow from the pump at
17200 kPa (2500 psi) and 2000 rpm. - Calculate the loss in flow by using the equation in table 1.
Show/hide table
Table 1 Percent flow loss [(A − B) ÷ A] × 100 = C A Pump output flow at 3450 kPa (500 psi) B Pump output flow at 17200 kPa (2500 psi) C Percent flow loss Show/hide tableTable 2 Example [(A − B) ÷ A] × 100 = D A 100 L/min (26.4 US gpm) B 98 L/min (25.9 US gpm) C Percent of flow loss [(100 L/min (26.4 US gpm) − 98 L/min (25.9 US gpm)) ÷ 100 L/min (26.4 US gpm)] × 100 = C C = 2% - The loss in flow from the output of the pump must not exceed 3 %. Ifthe loss in pump flow is greater than 3% then repeat steps 1 through 4 with an oil temperature at
66° ± 4°C (150° ± 10°F) . - If the loss in pump flow is still greater than 3% after step 5, then the pump needs to be replaced.