Information from TRW Integral Power Steering Gear Maintenance Manual
Normal Noises
You or the driver may hear a hissing noise from the control valve when it is actuated during a steering maneuver
You or the driver may hear a noise as fluid bypasses through the poppets at full turn.
You or the driver may hear a noise from the system relief valve when it is required to actuate.
You or the driver may hear pump growl from some types of power steering pumps.
Abnormal Noises
If the power steering pump is belt driven, a squealing noise may indicate that the belts should be tightened or replaced.
A clicking noise heard during a turn, or when changing directions, may indicate that some component is loose and shifting under load.
A change in the normal noise of the pump may indicate that air has been induced into the system or that fluid level is low.
Possible Steering Problems and Causes
Road Wander
Tire pressure incorrect or unequal left to right.
Components in steering linkage loose or worn (Steering wheel to road wheel)
Wheel bearings improperly adjusted or worn.
Front end alignment out of specification.
Dry fifth wheel or poor finish on fifth wheel or trailer plate.
Steering gear mounting bolts loose on frame.
Steering gear improperly adjusted.
Looseness in rear axle assemblies or trailer bogies.
No Recovery
Tire pressure low
Front end components binding
Tight front axle kingpins
Dry fifth wheel or poor finish on fifth wheel or trailer plate
Steering column binding
Pump flow insufficient
Steering gear improperly adjusted
Steering gear control valve sticking
Front end alignment incorrect
Shimmy
Badly worn or unevenly worn tires
Improperly mounted tire or wheel
Wheel bearings improperly adjusted or worn
Components in steering linkage loose or worn
Wheels or brake drums out of balance
Front end alignment incorrect
Air in the hydraulic system
External Oil Leakage
Finding the location of a leak mar be difficult, since oil mar run away from the leak source, the fittings, hoses, pump or gear to a low point on the gear or chassis.
A leak from the vent plug at the side cover indicates failure of the sector shaft oil seal inside the side cover.
Over steering or Darting
Dry fifth wheel or poor finish on fifth wheel or trailer plate
Front end components binding or loose
Steering column binding
Steering gear improperly adjusted
Steering gear control valve sticking
Rear axle mounts (rear steer)
High Steering Effort in One Direction
Unequal tire pressure
Vehicle overloaded
Inadequate hydraulic system pressure
Excessive internal leakage in one direction of turn only (verify with internal leakage test)
High Steering Effort in 80th Directions
Low tire pressure
Vehicle overloaded
Low hydraulic fluid level
Low pressure or flow from pump
Components of steering system binding
Restriction in return line, or line to a small in diameter
Excessive internal leakage (verify with internal leakage test)
Loose connection between the steering gear, intermediate column, and steering column.
Steering gear loose on frame
Pitman arm loose on output shaft .
Components in steering linkage loose or worn
Steering gear improperly adjusted
Excessive Heal Oil temperature not to exceed 120ºC Continuously
Excessive pump flow
Vehicle overloaded
Undersized replacement hose or line
Restricted hose or line that is kinked or severely bent or internally blocked
Restricted re-entering of gear valve caused by column bind or side load on the input shaft
Poppet not functioning properly
Prolonged stationary vehicle operation
WARNING: IF THE HYDRAULIC SYSTEM FLUID BECOMES OVERHEATED, IT CAN CAUSE THE SEALS IN THE STEERING GEAR AND PUMP TO SHRINK, HARDEN, OR CRACK AND LOSE THEIR SEALING ABILITY