HOSE 2505629 - Caterpillar

Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting and repair of the product. 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 on Caterpillar products.Dispose of all fluids according to local regulations and mandates.
Test Preparation
Manually test the input shaft in the steering control before you mount the steering control on the test bench. Be sure that the nominal travel of the input shaft equals 170 degrees. The input shaft must rotate freely without any obvious binding and the shaft must return to the spring centered position when the input torque is removed.The torque that is needed for the input shaft to contact the mechanical stops should not exceed a maximum of 4 N m (35 lb in).Determine Zero Input Position
The steering control should be mounted on a test bench in order to perform the following test:During Steps 1, 2, and 3 measure the following factors for each position of input shaft rotation:
Input angle position
Input torque
Slowly rotate the input shaft from the initial position to +10 1 degrees in the clockwise direction.
Slowly rotate the input shaft to -20 1 degrees in the counterclockwise direction.
Rotate the input shaft clockwise to the initial position (approximately 10 degrees in a clockwise direction).
Use the measured angle and the torque measurements to determine the "Zero" input position. The "Zero" input position is the angle that is midway between the torque values of +0.5 N m (+4.4 lb in) and -0.5 N m (-4.4 lb in).Note: The "Zero" input position is the initial starting point for plotting the test data for the functional test and the leakage test.Leakage Test
Illustration 1 g00572498
For the leakage test, the steering control should be mounted on a test bench with the oil at 27 °C (80.6 °F).
Block the outlet port (AL) and the outlet port (AR) .
Connect port (T) to the drain.
Apply leakage flow at 2500 100 kPa (360 15 psi) to port (P) .
Rotate the input shaft from +5 degrees through +165 degrees and -5 degrees through -165 degrees. The maximum allowable leakage under this condition is 1500 cc per minute.
Rotate the input shaft from +5 degrees and zero through -5 degrees. The maximum allowable leakage under this condition is 900 cc per minute.
If the leakage is too high, proceed to the "Functional Test". Adjust the plunger in Step 7 to 400 20 kPa (58 3 psi). Tighten locknut (2) in Step 8. Then, return to the Leakage Test and retest the steering control.Functional Test
Illustration 2 g00572315
Output Pressure Versus Input Position (A) Output (differential pressure) (B) Minimum pressure (C) "Zero" input position (D) Pressure at "knee" (E) Clockwise 170 degrees (F) Input position (G) Counterclockwise 170 degrees
Illustration 3 g00572498
Apply 10 L/min (2.6 US gpm) at 2500 100 kPa (360 15 psi) to port (P)