Suzuki XL7 2007 Service Manual page 1783

Power Assisted Steering System
Power Steering System Description and Operation
The hydraulic power steering system consists of the following components:
• The hydraulic power steering pump is a belt-driven, constant displacement vane-type pump that provides hydraulic
pressure and flow for the power steering gear.
• The power steering fluid reservoir holds the power steering fluid and is remote to the power steering pump.
• The power steering gear is a rack and pinion system. In the rack and pinion system, the rack and the pinion are the
2 components that convert steering wheel rotation to lateral movement. The steering shaft is attached to the pinion
in the steering gear. The pinion rotates with the steering wheel. Gear teeth on the pinion mesh with the gear teeth
on the rack. The rotating pinion moves the rack from side to side. The lateral action of the rack pushes and pulls the
tie rods in order to change the direction of the vehicle's front wheels.
• The power steering pressure hose connects the power steering pump union fitting to the power steering gear and
allows pressurized power steering fluid to flow from the pump to the gear.
• The power steering return hose returns fluid from the power steering gear back to the power steering fluid reservoir.
The power steering return line contains a line-type power steering fluid cooler.
In a typical power steering system, a pump generates hydraulic pressure, causing fluid to flow, via the pressure hose,
to the steering gear valve assembly. The steering gear valve assembly regulates the incoming fluid to the right and left
chambers in order to assist in right and left turns.
Turning the steering wheel activates the valve assembly, which applies greater fluid pressure and flow to one side of
the steering gear piston, and lower pressure and flow to the other side of the piston. The pressure assists the
movement of the gear piston. Tie rods transfer this force to the front wheels, which turn the vehicle right or left.
Diagnostic Starting Point - Power Steering
System
Begin the system diagnosis by reviewing the system
Description and Operation. Refer to "Power Steering
System Description and Operation". Reviewing the
Description and Operation information will help you
determine the correct symptom diagnostic procedure
when a malfunction exists. Reviewing the Description
and Operation information will also help you determine if
the condition described by the customer is normal
operation. Refer to "Symptoms - Power Steering
System" in order to identify the correct procedure for
diagnosing the system and where the procedure is
located.
Symptoms - Power Steering System
NOTE
Review the system description and operation
in order to familiarize yourself with the
system functions. Refer to "Power Steering
System Description and Operation".
Visual/Physical Inspection
• Inspect for aftermarket devices which could affect the
operation of the power steering system.
General Description
Diagnostic Information and Procedures
Power Assisted Steering System:
• Inspect the easily accessible or visible system
components for obvious damage or conditions which
could cause the symptom.
• Inspect for leaking power steering components. If
necessary, refer to "Power Steering Fluid Leaks".
• Verify the power steering reservoir for the proper
operating specification. Refer to "Checking and
Adding Power Steering Fluid".
• Inspect the power steering fluid for the following
indications of contamination:
– Milky fluid - water
– Brown fluid - burnt
– Debris in fluid - plastic or dirt
• If necessary, flush the power steering system. Refer
to "Power Steering System Flushing".
Symptoms List
Refer to a symptom diagnostic procedure from the
following list in order to diagnose the symptom:
• "Power Steering Fluid Leaks"
• "Rattle, Clunk, or Shudder Noise from the Power
Steering System"
• "Whine or Growl Noise from the Power Steering
System"
• "Steering Effort Hard in One or Both Directions"
• "Steering Effort Too Easy in One or Both Directions"
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