Chery A15. Manual — part 209

Chery A15 Maintenance Manual

3. Fault Diagnosis and Troubleshooting

(1). Check tire pressure and inflate as required in case of low pressure.

(2). Check oil pipe connections of steering hydraulic system, and tighten them if

leakage is found; check oil pipes, and replace damaged, distorted or cracked ones.

Adjust pretightening force of rack convex piece or replace steering gear rack if

necessary.

(3). Check steering gear rack and the turning condition at the center wheel position,

and check the rack bent and the adjustment of rack convex piece in case of excessive

turning torque. Adjust pretightening force of rack convex piece or replace steering

gear rack if necessary.

(4). Check steering control valve to see if there is any blockage or bad returning, and

replace the steering control valve when necessary.

(5). Disassemble and inspect hydraulic cylinder, and replace damaged parts.

(6). Make adjustments on ball pin at each connection of steering transmission

mechanism to insure smooth operation.

(II). Steering Wheel Vibration

1. Symptom

Steering wheel vibrates during operation when the engine is working, especially at the

extreme positions.

2. Possible Causes

(1). Steering oil pump belt skids.

(2). Too low oil tank level.

(3). Air enters steering hydraulic circuit.

(4). Insufficient steering oil pump output pressure.

(5). Blocked pressure regulator piston in steering oil pump.

3. Fault Diagnosis and Troubleshooting

(1). Check steering oil pump transmission belt to see if there is any skidding or

damage, and tighten or replace the belt when necessary.

(2). Check oil tank level for consistency, and add steering oil as required.

(3). Check all pipe joints in steering hydraulic system and eliminate any leakage

Chery A15 Maintenance Manual

found, then exhaust the air in oil circuit.

(4). Check steering oil pump output pressure. In case of underpressure, disassemble

the oil pump and check for wear or internal leakage, check pressure limiting valve and

pressure regulator piston for leakage or blockage, pressure regulator spring for weak

spring force, and oil pump sealing for damage. Identify fault cause and repair, or

replace oil pump if necessary.

(III). Light or Off-tracking Steering Wheel in Straight Running

1. Symptom

Vehicle is not going right ahead when running on a straight line and keeps going off

track towards one side.

2. Possible Causes

(1). Damaged or too soft steering control valve torsion bar is not able to overcome

reverse transmission resistance of steering gear, keeping valve bush from timely

returning.

(2). Movement of valve plug and valve bush is retarded due to contaminated oil.

(3). Steering control valve plug deviates from center position.

(4). Blocked pressure regulator piston of steering pump overflows pump oil and

causes large pressure difference between left and right cavities of power cylinder.

(5). Too large joint clearance of steering transmission system, or loose connecting

pieces, or severe wear.

3. Fault Diagnosis and Troubleshooting

(1). First check steering transmission mechanism for loose connecting piece, too large

component clearance and loose transmission to eliminate steering transmission

mechanism faults.

(2). Check if the oil is contaminated. New or overhauled vehicles sometimes have

contaminated oil for poor compliance with the oil-replacing requirement during

running-in period. Any contaminated oil shall be replaced.

(3). Check steering control valve. First turn the steering wheel with the engine not

working, and determine by hand feeling if the steering control valve is operating

smoothly. Disassemble and inspect in case of suspected situation.

Chery A15 Maintenance Manual

(4). Finally check the performance of steering oil pump pressure regulator to see if the

regulator piston is blocked. Check steering oil pump output pressure to facilitate

determination when necessary.

(IV). Steering Noise

1. Symptom

Too large noise occurs during steering.

2. Possible Causes

Too large noise from steering system during steering is considered to be a normal

phenomenon, and it is common that steering pump makes noise in the first 2-3

minutes after the engine is started in cold weather (-20ºC or lower). However, too

much noise or those affect steering performance are deemed as fault. The cause for

such fault may include:

(1). Loose steering transmission mechanism causes too large noise.

(2). Damaged or worn-out power steering pump or air in the oil causes too large

noise.

(3). Loose or skidding power steering pump transmission belt causes too large noise.

(4). Poor performance of steering control valve.

(5). Loose oil pipe connection or cracked oil pipe.

(6). Blocked oil filler strainer or too much deposition in hydraulic circuit.

3. Fault Diagnosis and Troubleshooting

(1). If a “click” sound is heard when steering, it may be caused by loose steering post

shaft adapter, steering knuckle tie rod or ball joint. Check these parts and fasten or

replace them if necessary. If steering post shaft wiggles badly, the steering post

assembly shall be replaced. Loose steering gear shall be fastened, and lubricant sites

at connections shall be lubricated. In addition, loose steering pump transmission belt

also makes “click” sound, so also check the belt and tighten or replace it to eliminate

the noise.

(2). If a “quack” sound is heard when steering especially when turning the steering

wheel from one extreme position to the other, it may be caused by skidding power

steering pump transmission belt. Check the belt tension and wearing condition, and

Chery A15 Maintenance Manual

tighten or replace it if necessary.

(3). If a “cluck” sound is heard when steering, it may be the aerodynamic noise

caused by air bubbles in flowing oil. First check the oil level, and add to the specified

level if it is too low before checking and eliminating fault. Then check to see if the

hose is damaged or the clamp is loose, allowing air to enter the system. Replace

damaged hose or clamp when necessary. In case air is found in power steering system

oil, exhaust the air to eliminate aerodynamic noise. If a “hissing” or a squealing sound

is made by steering pump while there is no air leakage in hydraulic system with the

transmission belt tension being normal, it may be caused by blocked oil circuit or

worn-out or damaged oil pump, which shall be repaired or replaced.

(4). If a large “hissing” sound is heard from steering gear when steering wheel is at

extreme positions or slowly turned in situ, it may be caused by bad performance of

steering control valve. Replace the control valve and recheck to eliminate the noise.