OPTION AR-LINKAGE 3966803 - Caterpillar

Pump Efficiency Check
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 the two operating pressures is the flow loss. Flow loss when expressed as a percent of pump flow is used as a measure of pump performance. If the percent of flow loss is more than 10%, pump performance is not good enough.*Numbers in examples are for illustration and are not values for any specific pump or pump condition. See Specifications for pump flow of a new pump at 690 kPa (100 psi) and 6900 kPa (1000 psi).Machine Test
Install a Flow Meter. For Formula I, measure pump flow at 690 kPa (100 psi) and at 6900 kPa (1000 psi) with the engine at high idle rpm. Bench Test
If the test bench can be run at 6900 kPa (1000 psi) and at full pump rpm, find the percent of flow loss using Formula I.If the test bench cannot be run at 6900 kPa (1000 psi) and at full pump rpm, run the pump shaft at 1000 rpm. Measure the pump flow at 690 kPa (100 psi) and at 6900 kPa (1000 psi). Use these values in the top part of Formula II. For the bottom part of the formula, run the pump shaft at 2000 rpm. Measure the pump flow at 690 kPa (100 psi). Steering Force Check
Check the force needed to turn the steering wheel very slowly.(a) Torque to turn the steering wheel when the engine is stopped ... 4.0 to 4.5 N m (35 to 40 lb in)(b) Torque to turn the steering wheel when the engine is at low idle ... 2.3 to 2.8 N m (20 to 25 lb in)Steering Time Check
To check the steering time, put the machine on a dry, hard surface. With the engine at high idle, the time for a full turn, from stop to stop, must not be more than 2.5 .4 seconds.The difference between the time for a right turn and the time for a left turn must not be more than .3 second. With the brakes activated, the time must not increase more than .2 second.If the difference between the times for a full right turn and a full left turn is more than .3 second:
Steering Control Valve
(1) Control valve. (2) Flow balance shims. (3) Cylinder flow shims.1. Remove the end cover from steering control valve (1).2. Add flow balance shims (2) to decrease the right turn time (steer faster) and increase the left turn time (steer slower). If the flow balance shims are removed, the result is opposite.3. Shims (2) are available in two thicknesses. 5J4776 Shims are 0.13 mm (.005 in) thick. Two 5J4776 Shims will change the steering time high idle by approximately .05 second. 4J8224 Shims are 0.25 mm (.010 in) thick. Two 4J8224 Shims will change the steering time at high idle by approximately