COWL 0005319 - Caterpillar

Remove the purge bolt (16) from the side of the cylinder before testing an ejector cylinder. This step will help to expel trapped air from the cylinder. Install a clear plastic line into the hole of the purge bolt (16). Place the other end of the line into a suitable container for collecting oil from the cylinder. Refer to Illustration 32.
Illustration 33 g02604441
(9) Start/stop switch
Start the hydraulic pump (5) by pushing START on the start/stop switch (9).
Illustration 34 g02615400
(6) Directional Control Lever
(7) Mode Selector Lever
Ensure that the"Test Pressure" knob (4) is turned counterclockwise so that the system pressure is zero. Refer to Illustration 34.
The mode selector lever (7) allows the user to select between the CYLINDER CYCLE position and the CYLINDER TEST position. Move the mode selector lever (7) to the CYLINDER CYCLE position. Refer to Illustration 34.
The directional control lever (6) is used to control the state or position of the cylinder. Place the directional control lever (6) in theROD RETRACT position, which is shown in Illustration 34. This setting will supply oil to the rod end of the cylinder. If the hoses have been connected correctly, the rod will retract. If the rod extends, the hoses must be switched. Relieve pressure before disconnecting the test hoses. Refer to Steps 15 and 16 to relieve system pressure.
Personal injury can result from removing hoses or fittings in a pressure system.Failure to relieve pressure can cause personal injury.Do not remove or disconnect hoses or fittings until all pressure in the air system has been relieved.
Illustration 35 g02604336
(4) Pressure Test Adjustment
Turn the "Test Pressure" knob (4) clockwise to increase pressure. When oil begins to flow out of the purge bolt (16) hole, move the directional control lever (6) to the center position. Refer to Illustrations 35 and to 34.
Reinstall the purge bolt (16). Refer to Illustration 32.
Move the directional control lever (6) back to ROD RETRACT. Fully retract the cylinder. Refer to Illustration 34.Note: Telescopic cylinders are only pressure tested in the full retract position. Other cylinders are stopped midway between retract and extend and then pressure tested.
Turn the "Test Pressure" knob (4) clockwise to increase the system pressure to the Test Pressure 20,680 kPa (3000 psi). Refer to Illustration 34.
Do not exceed the test pressure. Damage will occur to the seals if the pressure exceeds the test pressure amount.
Visually inspect the rod seals for oil leakage. If leakage occurs, perform Steps 14 through 20. Then, disassemble the damaged rod seal and replace the damaged rod seal.Note: There will be evidence of oil around the wiper seals on each stage of a retracted cylinder under normal operation. An ejector cylinder might have hydraulic oil around the wiper seals and the cylinder would be classified as seeping. Table 6 can help determine if the cylinder seals are working properly.
Table 6
Classification of Oil that is Evident from the Wiper Seals of the Ejector Cylinder
Classification Description
Moist Oil film does not result in forming droplets of oil.
Seep The oil film develops a visible droplet.
Weep Oil that reoccurs