PISTON G BASIC 4N4697 - Caterpillar

Personal injury or death can result from machine articulation or movement. Machine frames can move and a person can be crushed.Connect the steering frame lock between the front and rear frames before working on the machine.
Personal injury or death can result from escaping fluid under pressure.Escaping fluid under pressure, even a very small pin-hole size leak, can penetrate body tissue and cause serious injury and possible death. If fluid is injected into your skin, it must be treated by a doctor familiar with this type of injury.Always use a board or cardboard when checking for a leak.
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 Dealer Service Tool Catalog" for tools and supplies suitable to collect and contain fluids on Caterpillar products.Dispose of all fluids according to local regulations and mandates.
Performance tests for the steering system can be used for a diagnosis of poor performance and for finding the source of oil leaks inside the hydraulic system.This section provides probable causes to a known problem. Since there may be several probable causes, specific inspections or specific instrument tests may be recommended. These inspections and tests will help to identify the cause that is most probable.Note: Make sure that the you use hydraulic oil with the correct viscosity for the ambient temperature and for the operating conditions. To determine the correct oil viscosity, see the reference that follows. Reference: For additional information about the various lubricant viscosities, refer Operation and Maintenance Manual, "Lubricant Viscosities".Note: The following information is for both STIC and wheel steering machines. Problem 1: The machine turns slowly when the STIC steering control lever is moved or when steering wheel is turned.Probable causes
The oil is too cold.
There is a restriction in the pilot lines of the pilot valve.
The pilot lines to the pilot valve are not connected to the correct ports.
Steering pump pressure low.
Restriction in steering metering pump pilot lines (wheel steering).
Pilot lines to steering metering pump are not connected to proper ports (wheel steering).
Restriction across ball check valve at steering metering pump supply port in the steering control valve (wheel steering).
Bolts are too tight for metering section of the steering pump (wheel steering).
Illustration 1 g01020354
Timing of the metering pump drive (1) Pin (2) Rotor
Timing of the metering pump drive is not correct. Pin must align with the valley of the rotor. Problem 2: The machine responds slowly when the machine is steered quickly away from a full turn.Probable cause:
The steering neutralizer valves do not move freely.
Not enough clearance between ball check valve and plug assembly in steering neutralizer valve (wheel steering). The STIC steering control lever or steering wheel attempts to turn the machine when the machine is in a full turn.Probable causes:
The adjustment of the steering neutralizer valve is not correct.
Seal for the neutralizer ball check has a