TH103 Telehandler Steering System Caterpillar

Problem

The implement and steering pump is noisy and the steering is jerky.

Possible Causes

• The hydraulic oil level is too low. Refer to Operation and Maintenance Manual, SEBU7371, "Hydraulic System Oil Level - Check".

• Air is trapped in the system. Inspect the sight glass on the hydraulic tank for bubbles. If air is found in the system, check all lines, all connections, and all seals in the hydraulic system.

• The implement and steering pump is worn. Refer to Testing and Adjusting, "Steering System Pressures - Test and Adjust".

• The wrong hydraulic oil viscosity was used. Refer to Operation and Maintenance Manual, SEBU7371, "Lubricant Viscosities and Refill Capacities".

Problem

The steering wheel is difficult to turn.

Possible Causes

• The pump section of the metering pump is damaged. Replace the metering pump. Refer to Disassembly and Assembly, RENR3437, "Metering Pump (Steering) - Remove". The metering pump was formerly referred to as the steering valve.

• The margin pressure is set too low. Refer to Testing and Adjusting, "Steering System Pressures - Test and Adjust".

• The spool in the metering pump is sticking. Replace the metering pump. Refer to Disassembly and Assembly, RENR3437, "Metering Pump (Steering) - Remove". The metering pump was formerly referred to as the steering valve.

• A steering cylinder is damaged. Inspect the steering cylinders for damage.

• A resolver in the signal network is not functioning properly. Refer to Testing and Adjusting, "Signal Resolver Network - Test".

• The steering signal relief valve is set too low. Refer to Testing and Adjusting, "Steering System Pressures - Test and Adjust".

Problem

The steering system operates slowly.

Possible Causes

• The wrong hydraulic oil viscosity was used. Refer to Operation and Maintenance Manual, SEBU7371, "Lubricant Viscosities and Refill Capacities".

• A hydraulic line is restricted. Check the hydraulic lines for restrictions. Ensure that the lines are not kinked.

• The pump is producing insufficient flow. Refer to Testing and Adjusting, "Steering System Pressures - Test and Adjust".

• A steering cylinder is leaking. Inspect the steering cylinder for leaks.

• A resolver in the signal network is not functioning properly. Refer to Testing and Adjusting, "Signal Resolver Network - Test".

• The steering signal relief valve is set too low. Refer to Testing and Adjusting, "Steering System Pressures - Test and Adjust".

Problem

The rear steering fails to align when you change from four-wheel steer to two-wheel steer on machines with self-aligning rear steering.

Possible Causes

• The steering is out of synchronization. Refer to Operation and Maintenance Manual, SEBU7371, "Steering Alignment".

• The fuse for the steering circuit is faulty. Refer to Operation and Maintenance Manual, SEBU7371, "Fuses and Relays - Replace".

• There is an open circuit in the electrical system for the steering. Refer to Electrical Schematic, RENR3416.

• The steering position sensor is faulty. Refer to Systems Operation, "Position Sensor (Steering)" and Testing and Adjusting, "Position Sensor (Steering) - Adjust".

• The position sensor is adjusted incorrectly. Refer to Testing and Adjusting, "Position Sensor (Steering) - Adjust".

• The relay for the steering system is faulty. Check the relay for proper operation. Refer to Operation and Maintenance Manual, SEBU7371, "Fuses and Relays - Replace" for information on replacing relays. Refer to Electrical Schematic, RENR3416.

• The master steering select switch is faulty. Check the switch for continuity.

Problem

Crab steer and/or circle steer is inoperative.

Possible Causes

• The fuse for the steering circuit is faulty. Refer to Operation and Maintenance Manual, SEBU7371, "Fuses and Relays - Replace".

• There is an open circuit in the electrical system for the steering. Refer to Electrical Schematic, RENR3416.

• The solenoid on the steering selector valve is faulty. Refer to Testing and Adjusting, "Solenoid Valve - Test" for information on checking the solenoid. The spool is sticking in the steering selector valve.

• The mode select switch is faulty. Check the switch for continuity.

• The master steering select switch is faulty. Check the switch for continuity.

Problem

There is no steering.

Possible Causes

• The check valve in the metering pump is stuck open. Replace the metering pump. Refer to Disassembly and Assembly, RENR3437, "Metering Pump (Steering) - Remove".

• A steering cylinder has seized. Refer to Disassembly and Assembly, RENR3437, "Steering Cylinder - Remove".

• The implement and steering pump is faulty. Refer to Disassembly and Assembly, RENR3437, "Piston Pump (Implement and Steering) - Remove".

Problem

The steering wheel turns, but the wheels do not move.

Possible Causes

• The metering pump is contaminated with dirt. Replace the metering pump. Refer to Disassembly and Assembly, RENR3437, "Metering Pump (Steering) - Remove".

• The centering springs in the metering pump are faulty. Replace the metering pump. Refer to Disassembly and Assembly, RENR3437, "Metering Pump (Steering) - Remove".

• Air is trapped in the system. Inspect the sight glass on the hydraulic tank for bubbles. If air is found in the system, check all lines, all connections, and all seals in the hydraulic system.

• The seals on the steering cylinders are leaking. Inspect the steering cylinders for damage.

• The check valve in the metering pump is stuck open. Replace the metering pump. Refer to Disassembly and Assembly, RENR3437, "Metering Pump (Steering) - Remove".

• The steering column is faulty. Check the column for damage.

• The hydraulic oil level is too low. Refer to Operation and Maintenance Manual, SEBU7371, "Hydraulic System Oil Level - Check".

Problem

The machine continues to steer when the steering wheel has stopped turning.

Possible Causes

• The metering pump is faulty. Replace the metering pump. Refer to Disassembly and Assembly, RENR3437, "Metering Pump (Steering) - Remove".