PUMP GP-GEAR 2993941 - Caterpillar

Problem
Turning the steering wheel is difficult.Probable Cause
The oil is cold.
The pilot lines to the steering metering pump are restricted.
The pilot lines to the steering metering pump are not connected to the proper ports.
The bolts are too tight on the metering section of the steering metering pump.
The steering pump pressure is low.
The timing of the steering metering pump drive is not correct. The timing pin must align with the valley of the star gear.
The main control spool is sticking in the bore.
The steering column may bind due to misalignment.
Controlled cylinder flow is low.Problem
The machine does not turn when the steering wheel is turned.Probable Cause
The flow control spool will not move from the open position.
A defect in the pilot relief valve or the seat may cause the steering to slip.
There is air in the steering system.
The setting for the crossover relief valve is low.
The pilot lines are connected to the wrong ports.
The check valve is open to the tank.Problem
The steering is jerky.Probable Cause
The servo pilot system has failed or the servo cylinder has failed.
The pilot-operated check valves are dirty or sticking.
The flow control spool does not move freely.
The orifice check valve in the steering control valve sticks open.Problem
There is excessive drift in the steering system.Probable Cause
There is air in the steering system.
The servo pilot system leaks.
The valve spool in the steering control valve needs adjusting.Problem
The steering is spongy.Probable Cause
There is air in the servo pilot system.
There is air in the steering system.Problem
Erratic steering (excessive slip)Probable Cause
The pressure reducing valve sticks.
The flow control spool sticks.
The control valve spool sticks.
The steering system is contaminated.
There is air in the steering system.
The differential lock or the brakes are activated.
The servo pilot system malfunctions.Problem
There is excessive free play in the steering system.Probable Cause
There is air in the servo pilot system.
The servo pilot system leaks.
The pressure reducing valve sticks.Problem
The machine turns slowly in one direction.Probable Cause
The main control spool does not achieve full travel.
The servo pilot system leaks.
The stem seals leak for the resolver.
The seals on the steering cylinder leak.
The check valve leaks in the crossover relief and check valve.Problem
The machine turns too slowly.Probable Cause
The springs for the flow control spool are not adjusted correctly.
Not enough oil flow from the primary pump.
The main control spool does not achieve full travel.
The stem seals leak for the resolver.
The seals on the steering cylinder leak.
The check valve leaks in the crossover relief and check valve.
The orifice check valve in the steering control valve sticks open.
The main relief valve is malfunctioning or the main relief valve pressure is set too low.Problem
The steering pump makes noise but the cylinder rods do not move smoothly.Probable Cause
The steering pump is leaking air into the system.
The pump is worn.
The viscosity of the oil is wrong.
The relief valve setting is wrong.
The steering system is contaminated.Problem
The temperature of the oil is too hot.Probable Cause
The viscosity of the oil is wrong.
The relief valve setting is too low.
The pump is worn.
There is a restriction in an oil passage.
The load on the system is too high.
The seals on the