ROLLER & BEARING AS 6Y9859 - Caterpillar

Pump Efficiency Test
Make reference to the on the first page of the Testing And Adjusting section.This test is designed to tell if a pump is operating within design parameters.For any pump test at a given rpm, the pump flow at 690 kPa (100 psi) will be larger than the pump flow at 6900 kPa (1000 psi).The difference between the pump flow of two operating pressures is the flow loss.Flow loss is used as a measure of pump performance when flow loss is expressed as a percent of pump flow.Percent of flow loss equation.[(A - B) ÷ C] * 100 = D Example of finding percent of flow loss. [(217.6 L/min - 196.8 L/min) ÷ 217.6 L/min] * 100 = 9.6%If the percent of loss is more than 15% for test on the machine or 10% for test on the bench, pump performance is NOT good enough.Numbers in example are only for illustration. These numbers are not values for any specific pump or pump condition. See the 772B Tractor & 773B Truck Steering System, Specifications, SENR6877 for pump flow of a new pump at 690 kPa (100 psi) and at 6900 kPa (1000 psi).Test On Machine
Install a 9S-2000 Flow Meter. Start the engine. Operate the engine at HIGH IDLE. Measure the pump flow at 690 kPa (100 psi) and at 6900 kPa (1000 psi). Use these values in the formula.Test On Bench
If the bench can be operated at 6900 kPa (1000 psi) and at full pump rpm, find the percent of flow loss.If the test bench cannot be operated at 6900 kPa (1000 psi) and at full pump rpm, operate the pump shaft at 1000 rpm. Measure the pump flow at 690 kPa (100 psi) and 6900 kPa (1000 psi). Use these values in the top part of the equation. For the values on the bottom part of the equation, run the pump shaft at 2000 rpm. Measure the pump flow at 690 kPa (100 psi) and use this value.Relief Valve In The Flow Control Valve Pressure Test
Make reference to the on the first page of the Testing And Adjusting section.
Relief Valve For Cylinders.
(1) Pressure taps.Install a pressure gauge on the pressure tap of the relief valve for the cylinders. Start the engine and operate the engine at high idle rpm. Look at the pressure gauge and turn the steering wheel in both directions. Do not keep the steering wheel against the stop for more than three seconds. The high pressure reading on the gauge is the setting of the relief valve in the flow control valve. The correct pressure setting is 15 500 170 kPa (2250 25 psi).Relief Valve In The Flow Control Valve Adjustments
Flow Control Valve
(2) Nut. (3) Adjusting screw. (4) Relief valve.Make reference to the on the first page of the Testing And Adjusting section.If it is necessary to make an adjustment to the pressure setting of the relief valve (4), loosen the nut (2) and turn the adjusting screw (3) clockwise (CW) to