IT14G Integrated Toolcarrier and 914G Wheel Loader Steering System Caterpillar

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Personal injury or death can result from sudden machine movement. Sudden movement of the machine or release of oil under pressure can cause injury to persons on or near the machine. To help prevent possible injury before testing and adjusting any hydraulic system, perform the procedure that follows:

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Personal injury can result from hydraulic oil pressure and hot oil. Hydraulic oil pressure can remain in the hydraulic system after the engine has been stopped. Serious injury can be caused if this pressure is not released before any service is done on the hydraulic system. Make sure all of the attachments have been lowered, oil is cool before removing any components or lines. Remove the oil filler cap only when the engine is stopped, and the filler cap is cool enough to touch with your bare hand.

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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.

This section provides probable causes to known problems. Since there may be several probable causes, specific inspections or instrument tests may be recommended. These inspections and tests will help to identify the causes that are most probable.

Note: Make sure that you use an oil with the correct viscosity for the operating conditions. To determine the correct oil viscosity, refer to Operation and Maintenance Manual, "Lubricant Viscosities and Refill Capacities" for your machine.

Problem List for the Steering System

1. The steering and brake pump makes noise and the steering cylinder rods do not move smoothly.

2. The temperature of the oil is too hot.

3. Too much force is required to turn the steering wheel.

4. The machine does not turn when the steering wheel is turned.

5. The machine turns too slowly in both of the directions.

6. The machine turns too slowly in one direction.

7. The steering wheel turns without assistance from the operator.

8. The steering wheel does not return to the center position correctly.

9. The output pressure from the steering and brake pump is too low.

10. The oil pressure is low.

Problem 1

The steering and brake pump makes noise and the steering cylinder rods do not move smoothly.

1. There is air in the steering system.

2. The output pressure from the steering and brake pump is too low. The pump is worn.

3. The connections on the inlet side of the steering and brake pump are loose.

4. The hydraulic oil level in the tank is low.

5. The viscosity of the oil is incorrect.

6. The suction strainer in the hydraulic tank is blocked.

7. The cylinder relief valve in the 113-1726 Metering Pump opens below the specified pressure.

Problem 2

The temperature of the oil is too hot.

1. The viscosity of the hydraulic oil is incorrect.

2. There is air in the hydraulic oil.

3. Air flow to the cooler is blocked.

4. The hydraulic oil level in the tank is low.

5. The pump is worn.

6. The cylinder relief valve in the 113-1726 Metering Pump opens below the specified pressure.

7. There is a restriction in an oil passage.

8. The load on the system is too high.

Problem 3

Too much force is required to turn the steering wheel.

1. The steering wheel is turned too fast in low idle.

2. There is a blocked signal path or a plugged orifice in the priority valve.

3. The spool in the priority valve is sticking.

4. The hydraulic oil level in the tank is low.

5. The hydraulic oil is cold.

6. There is air in the hydraulic oil.

7. The steering cylinders are worn.

8. There is a restriction in the supply line to the metering pump.

9. The cylinder relief valve in the 113-1726 Metering Pump is not opening correctly.

10. There is insufficient oil flow to the metering pump.

11. The output pressure from the steering and brake pump is too low. The pump is worn.

12. The hydraulic system is contaminated.

13. The metering pump is worn.

14. The spring in the priority valve is broken.

Problem 4

The machine does not turn when the steering wheel is turned.

1. The hydraulic oil level in the tank is low.

2. The hydraulic oil is cold.

3. There is air in the hydraulic oil.

4. The steering cylinders are worn.

5. There is a restriction in the steering linkage.

6. The spool in the priority valve is sticking.

7. There is a restriction in the supply line to the metering pump.

8. The anticavitation valves and the cylinder relief valves for 113-1726 Metering Pump are stuck open.

9. There is a blocked signal line or there is a plugged orifice in the priority valve.

10. The output pressure from the steering and brake pump is too low. The pump is worn.

11. The hydraulic system is contaminated.

12. The metering pump is worn.

13. If equipped, the secondary steering is not working.

Problem 5

The machine turns too slowly in both directions.

1. There is not enough oil flow from the steering and brake pump.

2. There is a restriction in the supply line to the metering pump.

3. The metering pump is worn.

4. The operation of the cylinder relief valve and the anticavitation valve are not operating correctly.

5. The seals for the steering cylinders are leaking.

6. The check valve for 119-8768 Metering Pump and 113-1726 Metering Pump is stuck open.

Problem 6

The machine turns too slowly in one direction.

1. The anticavitation valves and the cylinder relief valves for 113-1726 Metering Pump are stuck open.

2. There are restrictions in the metering pump.

3. The seals for the steering cylinders are leaking.

Problem 7

The steering wheel turns without assistance from the operator.

1. There is foreign material in the metering pump that causes the sleeve to stick to the spool.

2. The centering springs for the metering pump are broken or damaged.

Problem 8

The steering wheel does not return to the center position correctly.

1. The steering column is not aligned correctly with the metering pump.

2. The centering springs in the metering pump are worn.

3. There is foreign material in the metering pump that causes the sleeve to stick to the spool.

Problem 9

The output of the pump is too low.

1. The hydraulic oil level in the tank is low.

2. The viscosity of the oil is incorrect.

3. The output pressure from the steering and brake pump is too low. The pump is worn.

Problem 10

The oil pressure is low.

1. The cylinder relief valve in 113-1726 Metering Pump is stuck open.

2. The output pressure from the steering and brake pump is too low. The pump is worn.

3. An O-ring seal has failed in the hydraulic system.