CONTROL & MTG GP-ENGINE ELEK 2758194 - 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 link between the front and rear frames before working on 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 immediately 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, "Dealer Service Tool Catalog" for tools and supplies suitable to collect and contain fluids on Cat products.Dispose of all fluids according to local regulations and mandates.
Performance tests for the steering system can be used for diagnosis of poor performance. Performance tests can also be used 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 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.ReferenceFor additional information about the various lubricant viscosities for your machine, refer to the section "Lubricant Viscosities" in the appropriate Operation and Maintenance Manual for your machine.Command Control Steering
Problem List
Turning the steering wheel is difficult.
The steering wheel will not return to the NEUTRAL position. The machine is steering all of the time.
The impact at full articulation is too high.
The machine turns too slowly in one direction.
The machine turns too slowly in both directions.
The machine turns too slowly in both directions only when the machine turns against a load.
The machine does not turn when the steering wheel is turned.
The machine turns but the operator does not turn the steering wheel.
The machine turns too quickly in order to make small steering corrections when the machine moves at fast speeds.Problem 1: Turning the steering wheel is difficult.Probable causes:
The port plate in the pilot valve is binding.
One or both of the constant velocity joints is binding.
The pilot valve spool is binding.
The cam and the follower for the pilot valve is binding.Problem 2: The steering wheel will not return to the NEUTRAL position. The machine is steering all of the time.Probable causes:
The port plate in the pilot valve is binding.
One or both of the constant velocity joints that are in the steering shaft are binding.
The pilot valve spool is binding.
The cam and the follower for the pilot valve is binding.
The torsion spring in the pilot valve is broken.Problem