Chery A15. Manual — part 208

Chery A15 Maintenance Manual

system parts if not.

2. Checking Steering Knuckle Tie Rod

(1). Check tie rod ball, and replace if it is found loose in ball joint.

(2). Check tie rod ball dust boot and repair or replace it if it is damaged.

3. Checking Steering Gear

(1). Check steering gear dust cover and replace any cracked one to prevent water and

dust from entering the parts and causing early part damage. Check if the dust cover

clamp is well fixed.

(2). Check steering gear clearance and adjust if not proper.

4. Checking Hydraulic Assistant Pump

(1). Check assistant pump and replace if it is found blocked.

(2). Check assistant pump bearing and replace if abnormal sound is heard.

(3). Check hydraulic system and replace if leakage is found.

IV. Airtightness Inspection of Power Steering System

Airtightness inspection of power steering system shall be perform when warming up

the vehicle. Inspection steps:

(1). Turn the steering wheel quickly to left and right extreme positions and hold still

to maximize the system pressure.

(2). Visually inspect steering control valve, rack gear seal, vane pump (power steering

pump), oil pipe connection, and replace sealing elements if oil leakage is found.

(3). Check oil tank, and then the airtightness of power steering system if the oil tank is

short of ATF oil.

(4). If the gear rack sealing element in power steering gear shell is not working, ATF

oil may flow into corrugated tube, in this case all sealing rings in the steering system

shall be replaced.

(5). Check the oil pipe connection of power steering system, in case of oil leakage

check for cause and reconnect it.

Chery A15 Maintenance Manual

V. Inspection and Replacement of Hydraulic Assistant Oil

1. Checking Oil Mass

(1). Idle run the engine, and repeat the operation of turning steering wheel from one

extreme position to the other to increase power steering oil temperature to 40-80ºC.

(2) Check oil mass in oil tank, the oil level shall reach “MAX” mark. In case of low

oil level, check all parts for leakage before adding power steering oil to the “MAX”

mark as required.

Note: It is recommended to use a special device to vacuumize the oil tank when

adding power steering oil, otherwise the following procedure shall be followed

when adding power steering oil and exhausting air (e.g. when repairing): add

power steering oil to reach the max level in oil tank assembly, and run the engine

at low (idle) speed to drive steering pump and fill quickly the steering system

with hydraulic oil. The engine is only allowed to idle run when adding oil to dirve

vane pump, meanwhile hydraulic oil shall be added in time to avoid low oil level

and air intake by vanes.

2. Replacing Hydraulic Oil

(1). Jack up front axle and drain old oil from oil tank and return tube.

(2). Idle run the engine, turn the steering wheel to extreme positions when draining

until all hydraulic oil is drained out.

Note: This procedure must be completed as quickly as possible to protect

hydraulic assistant pump.

(3). Add power steering oil.

(4). Exhaust air in steering hydraulic system.

Chery A15 Maintenance Manual

3. Exhausting Air in Steering Hydraulic System

(1) Check oil level and add oil if necessary.

(2). Idle run the engine and keep turning steering wheel from left extreme position to

right extreme position until no bubble or foam is seen in oil tank. In case that oil level

falls, keep adding hydraulic oil until the specifed level (MAX) is reached.

(3). Air exhaust is relatively difficult for this model. Any bubble in system will cause

abnormal sound in hydraulic assistant pump.

VI. Inspection of Power Steering Pump Output Pressure

Check power steering pump for output oil pressure to determine if there is any fault

with power steering pump or steering gear. To measure exactly output oil pressure of

power steering pump, make oil tank level normal and power steering pump belt

tension compliant before measuring.

Measure the output oil pressure of power steering pump with a pressure gauge by

connecting the pressure gauge and hand valve serially in the system. At the moment

the engine stops rotating, dismount the pressure line from the power steering pump,

and connect one end of pressure gauge to the vent hole joint of the pump, the other

end of hand valve to the input hole of steering control valve, thus serially connecting

pressure gauge and hand valve in the pressure pipeline of power steering pump and

steering control valve.

Steps for checking power steering pump output oil pressure:

(1). Fully open hand valve.

(2). Start and idle run the engine.

(3). Turn steering wheel between left and right extreme positions for several times to

warm up steering oil to 80ºC, meanwhile maintain a normal oil level.

(4). Measure static oil pressure when the engine speed is 800r/min. The pressure

gauge reading shall be at least 300kPa (the minimal pressure when no steering) under

good condition of power steering pump.

(5) Slowly shut hand valve until gauge hand is stable, then read the pressure value,

Chery A15 Maintenance Manual

which shall be at least 6.2-6.9Mpa; any lower value indicates low output pressure of

steering pump and ineffective power assisted steering. The power steering pump is at

fault, and need repair or replacement.

VII. Fault Diagnosis and Troubleshooting of Power Steering System

Common faults of hydraulic power steering system include oil leakage at hydraulic

transmission part, air intake, power steering pump failure, steering control valve

damage and mechanical transmission part damage, etc. The symptom may be heavy

steering, steering noise, unsmooth steering and steering vibration, etc. Fault diagnosis

shall be carried out immediately after fault occurs to power steering system to

eliminate the fault in a timely manner.

(I). Heavy Steering

1. Symptom

Steering of vehicle equipped with power-assisted steering becomes heavy instead of

easy, or it becomes difficult to turn the steering wheel.

2. Possible Causes

Generally speaking, heavy steering is caused by hydraulic steering assistant system

failure or insufficient assistance, damaged mechanical transmission or improper

adjustment, the specific cause may be:

(1). Oil tank leakage or oil level lower than required value.

(2). Bad sealing of oil pipe connection and leakage.

(3). Air enters steering hydraulic circuit.

(4). Oil pipeline is distorted and oil circuit is blocked.

(5). Insufficient tension of power steering pump belt, skidding belt.

(6). Internal wear of steering oil pump and severe leakage make the oil pump output

pressure lower than standard value.

(7). Pressure regulator failure in the oil pump results in too low output pressure.

(8). Internal leakage of steering control valve and hydraulic cylinder.

(9). Damaged steering gear or improper adjustment.