Chery automobile Service Manual page 299

DIAGNOSIS AND TROUBLESHOOTING OF POWER STEERING
The frequent malfunctions of the hydraulic power steering system are the oil leakage,
infiltration of air, failure of the power steering pump, and damage of the steering control
valve and mechanical transmission mechanism of the hydraulic transmission mechanism. All
these malfunctions show in different forms, such as steering heavily, noise, unsmoothness,
vibration and so on. When the power steering system is in trouble, please diagnose the failure
and eliminate it at once.
Steering heavily
Malfunction symptom
In general, the steering should be easy for a vehicle with power steering system. If it fails, the
steering would be heavy and the steering wheel would be hard to turn.
Malfunction reason
Generally, it is caused by the invalidation or the insufficient power of the hydraulic power
steering system; Damage or improper adjustment of the mechanical transmission mechanism.
The specific reasons are shown below:
·
The oil reservoir leakage or oil level is lower than the specified value.
·
The oil tube connectors is not well sealed, leakage always happens.
·
The air enters the steering hydraulic loop.
·
The oil tube is deformed; Oil pipeline is blocked; oil pressure or flux of the oil pump is
insufficient.
·
The tension of the power steering pump driving-belt is insufficient and the belt slides.
·
The wear and leakage in the steering pump are serious, which makes the output pressure of
the oil pump lower than the standard.
·The pressure regulator oil pump fails, and the output pressure is too low.
·
There is internal leakage in the steering control valve and power hydraulic cylinder
·
The steering pinion mechanism is damaged or adjusted improperly, steering link system
components are bended, and friction force on every ball pin is too large.
·
The tire pressure is too low.
·
Front wheel alignment is not accurate.
·
The vehicle is overloaded seriously.
Diagnosis and Troubleshooting
SYSTEM
N-22