2008 GREAT WALL FLORID maintenance

Downloaded from www.Manualslib.com manuals search engine 109Brake System
3. Installing the ABS rear wheel speed sensor with brack-
et assembly.
Use three hexagon head bolts, spring washers, and flat
washer subassembly connecting pieces to connect the sensor
to the rear hub unit, rear twist beam, and vehicle body.
ABS General Problem Maintenance and Areas of Importance
Common problems and solutions
1. When braking, the ABS hydraulic pressure unit noise is overly loud.
When the ABS is working, the motor inside the hydraulic pressure unit is ceaselessly rotating. At this time the
driver can feel the brake pedal bouncing back. However, this bounce back feeling will be entirely different
depending on the speed and road condition. Also, when performing an actuator movement test, the sound of the
running motor may also be sensed. When the vehicle is being driven and the brake is off, the sound of the motor
running can still occasionally be heard. This is the ABS undergoing component inspection, not a malfunction.
If the ABS hydraulic pressure unit noise is irregular, a movement test can be initiated. Compare the noise to that
of normal vehicles to determine if ABS hydraulic pressure unit noise is abnormal.
2. Inlet and outlet solenoid valve failure.
Once the ignition switch is ON, the ABS control unit automatically initiates a self-check. If an inlet and outlet solenoid
valve short circuit or open circuit is found, it will record the failure, light up the fault light, and abort the operation. If using a
scanner to adjust the problem code, make sure to use the movement test t\
o confirm that the solenoid valve has a problem and
then replace the hydraulic pressure unit directly.
X431 data flow: While the ABS is functioning, the inlet and outlet solenoid valves rapidly change operating
conditions.
EVFL - Front inlet valve LHOff / On
AVFL - Front outlet valve LHOff / On
EVFR - Front outlet valve RHOff / On
AVFR - Rront outlet valve RHOff / On
EVRR - Rear inlet valve LHOff / On
AVRR - Rear outlet valve LHOff / On
EVRR - Rear inlet valve RHOff / On
AVRR - Rear outlet valve RHOff / On
3. Wheel speed sensor malfunction.
With the engine running, use a oscilloscope to measure the voltage between the sensor's signal line and the
ground.
Output signal when wheel is stationary:
Output signal when the wheels are rotating: signal type is 0.44 V and 1.26 V square wave signal, duty cycle: 50: 50.
Rear hub unit assembly
Rear wheel speed sensor with bracket assembly
Hexagon head bolt, spring washer, and flat washer subassembly
Hexagon head bolt, spring washer, and flat washer subassembly
0
v
t
vv
0 0
tt
or

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The X431 scanner possesses a waveform function. Wheel speed signal error (wheel speed sensor failure)
only appears when intermittent problems occure, such as high speed. When in use, some signal errors may
occasionally appear. Continue observing the waveform to make sure there is nothing abnormal.When driving
the vehicle on a flat and straight road, all four wheels' speed sensor waveform are extremely similar. One can
compare the two front wheels' with the two rear wheels' signal wave at t\
he same time.
Mechanical causes:
Signal gear distortion, loosened hub bearings, smudges on the sensor surface, etc, all may lead to wheel speed
signal intermittency and inaccuracy. Failure examples:
As shown above, once the intermittent failures with the wheel's speed sensor signal are detected, the ABS
control unit records the sensor problems and lights up the warning lamp.\
4. Wheel speed sensor velocity failure (ECU detects an excessive difference between the two wheels'
speed sensor signals).
Possible causes are the gear's wheel speed sensor gap is overly large, or the wheel speed sensor signal is
experiencing interference. For this, first determine which sensor is emitting the signal, and then use failure
three's maintenance methods.
Areas of Importance
1. Sometimes, in order to determine whether there is a common brake system problem or an ABS
problem, the ABS must be terminated by pulling out its ABSECU connector or fuse. At this time the
ABS/EBD loses function as well. On muddy, icy, or snowy roads, the vehicle may fishtail or slide, in
which cases one must be extremely careful to avoid hard braking.
2. The ABS malfunction rate is extremely low, when the brake system shows any problem (before the
warning lamp goes on), first eliminate the normal brake system problems, then consider the ABS mal-
functions.
3. When raining or on gravel, this adjusting process is longer than the standard process, because this
kind of road's unstable adhesion coefficient will lead to a difference between the sliding measurement
and calculation procedures, thus it is necessary to remind drivers to be especially careful when driving
under the circumstances mentioned above.
4. ABSECU Areas of Importance:
(a) The ABSECU is easily damaged from impacts or collisions, thus pay attention to ensure the ECU avoids
such incidents.
(b) High temperature environments can also easily damage the ECU, so when the vehicle undergoes hot paint
work, make sure to first take the ECU out of the vehicle.
(c) When the power switch is ON, do not disassemble the system's electrical elements and wire harness plugs,
in order to avoid damage to the ECU. If removal or installation must be carried out, be sure to disconnect
the ignition switch firstly. When welding components or circuits to the system, the wire harness plug
V( Km/h)
60
30
Signal interrupt
t

Downloaded from www.Manualslib.com manuals search engine GWFLORID Maintenance Manual112
Steering Knuckle and Hub Brake Assembly
Components
Disposable parts
Steering knuckle and hub brake assembly
examination and disassembly
1. Hoist the vehicle and remove the wheels.
2. Loosen the riveted areas of the front drive shaft nut
and remove the nut.
3. Inspect the front brake disc plate surface runout.
When measuring, tighten the two wheel nuts' symmetrical
locations. The front brake disc's brake linings runout on the
two sides should be no more than 0.11 mm. If oversized,
they should be repaired or replaced.
4. Inspect front brake disc thickness.
Standard thickness: 22.0 mm
Minimum thickness: 20.0 mm
The brake disc must be changed when it reaches the minimum
level of thickness.
Front brake caliper assembly LH
Copper washer
Hollow bolt
♦Heavy duty spring washer
Snap ring for hole 72
♦Front hub
bearing assemblyLeft steering knuckle
Left brake disc cover
♦Hexagon head bolt and
spring washer subassembly
Wheel bolt
Front hub flange
Front brake disc
100 ± 10
: Specified torqueN·m
9 ± 2

Downloaded from www.Manualslib.com manuals search engine GWFLORID Maintenance Manual114
(d) Measure the front hub bearing's starting torque.
Put the SST on the wheel bolts which are at the symmetric
locations. Put a dial torque wrench on the SST to slowly
rotate the flange assembly (45°/4s), requiring a starting
torque range of 0.1-0.3 N·m.
If the bearing rotation is not flexible, the front hub flange
plate surface movement inaccurate, or front hub bearing
starting torque is too much. The assembly must be replaced.
Steering knuckle's front hub bearing and
front hub flange assembly
1. Removal and inspection of front hub flange assembly.
(a) Use SST like a hand held travel hammer to repeatedly
hammer off the front hub flange assembly from the
steering knuckle and front hub bearing. Remove the
front hub with bearing's inner ring.
(b) Remove the bearing's inner ring on the front hub.
Use SST to remove the bearing's inner ring.
SST
SST
Bearing inner ring
SST
(c) Use dye penetrant to inspect the front hub flange for
cracks, which should be replaced if found.
(d) If one would like to continue using the front hub flange
assembly, first inspect the dimensions for the mounting
area of the bearing for inaccurate dimensions. If
oversized, replace.
Measurement range: Φ38+0.025 +0.009 mm
2. Remove the steering knuckle's front hub bearing.
3. Remove the snap ring for hole 72.
Use a bent nose retaining ring caliper for holes to remove the
snap ring for hole 72.

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3. Examine the front hub flange plate surface runout.
Examining methods are the same as the methods used
during disassembly. Plate surface runout should not exceed
0.03 mm.
4. Examine the front hub bearing assembly's starting
torque.
Examining methods are the same as the methods used during
disassembly. Put the SST on the wheel bolts which are at the
symmetrical locations. Put a dial torque wrench on the SST to
slowly rotate the flange's flange assembly (45°/4s), which re-
quires a starting torque range of 0.1-0.3 N·m
5. Install the snap ring for hole 72.
Use a bent nose retaining ring caliper for holes to install the
snap ring for hole 72 at the steering knuckle's retaining ring
mounting position.
6. Install the steering knuckle's front hub bearing and
front hub flange assembly.
7. Install the front brake disc cover.
Install the front brake disc cover on the steering knuckle, and
tighten the bolt to the set torque.
Tightening torque: 9±2 N·m
SST
8. Install the front brake disc.

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Front Brake Caliper
Components
Disposable parts
Inner and outer brake pad assembly re-
placement
Remark: When applying the brake while driving, if the front
tires makes a continuous screeching sound, inspect the inner
and outer brake pad and friction limit alarm plate. If there
are traces of rubbing from the brake disc on the alarm plate,
the inner and outer brake pad assembly should be replaced.
1. Remove the front wheel.
2. Inspect the inner and outer brake pad's friction material
thickness.
By looking through the caliper's observation ports, inspect
the inner and outer brake pad friction material thickness. If it
is no longer within the specified range, it should be replaced.
Minimum thickness: 2.0 mm
Bleed screw cap
Air bleed screw
Caliper
Rectangular sealing ring
Piston
P iston dust cover
Inner muffler plate subassembly
Alarm plate
Inner brake pad assembly
Outer brake pad assembly
Outer muffler plate subassembly
Guide pin
Guide pin dust cover
Caliper frame
Brake block yoke spring plate
Brake block yoke spring plate
30 ± 5
: Specified torqueN·m
10 ± 2
Q1840820
Rubber grease

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8. Install a new inner and outer brake pad assembly and
inner and outer muffler plate subassembly.
(a) Install inner shim A and B onto the inner brake disc.
(b) Install outer shim A and B onto the outer brake disc.
(c) Install the inner and outer brake pad assembly with
inner muffler plate subassembly onto the caliper frame.
Make the inner brake pad assembly with inner muffler
plate subassembly and alarm plate rest close to the
brake caliper's inner side.
Caution: For the inner and outer brake pad assembly,
the working surface of the brake disc must not have
any grease, oil or paint pollution.
(d) S i p h o n a s m a l l a m o u n t o f b r a k e f l u i d f r o m t h e
reservoir. (Make sure not to let the brake fluid overflow
from the reservoir).
(e) Press in the piston with SST.
9. Install the caliper assembly.
Loosen the rope, remove the caliper assembly, and tighten
the hexagon bolt for flange face.
Tightening torque: 30±5 N·m
Remark: Replace one wheel's brake pad at a time, in order to
avoid the other wheel's piston from springing out.
10. Install the front wheel.
Tightening torque for the wheel retaining nut: 100±5 N·m
Front brake caliper piston removal
1. Remove the brake line.
Remove the brake line, and use a clean container to hold the
brake fluid.
SST
Outer shim B
Outer shim AInner brake disc
Warning device
Inner shim B
Inner shim A
Outer brake disc
Inner muffler plate subassembly
Alarm plate
Inner brake pad assembly
Outer brake pad assembly
Outer muffler plate subassembly

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Front brake caliper assembly installation
1. Preparations
Make sure all parts are clean and free of foreign materials
before installation.When installing, apply an appropriate
amount of rubber grease to the guide pin and piston's
working surface, as well as the rectangular sealing ring and
the piston protective cover's working surface.
2. Install the rectangular sealing ring to the caliper.
(a) Screw the bleed screw into the caliper's vent holes.
Tightening torque: 10±2 N·m
(b) After applying an appropriate amount of rubber grease
on the rectangular sealing ring's working surface, install
them into the caliper's seal groove.
3. Install the piston with piston dust cover on the caliper.
(a) Place the piston dust cover on the piston.
(b) Stretch the piston dust cover, until its card holder
exposes the bottom of the piston. Use tools (for
example, about Ф2 mm of iron wire) to assist by
stuffing the card holder into the cylinder bore card
holder's groove.
Caution: The tools being used should not be sharp, as
to avoid tearing the dust cover.
(c) Then manually press the piston into the bottom of the
cylinder bore.
4. Install the guide pin and guide pin dust cover onto the
caliper frame.
(a) Install the guide pin dust cover onto the guide pin.
(b) Screw the guide pin into the caliper frame.
Caution: Do not damage the guide pin dust cover.
5. Install an inner and outer brake pad assembly and
inner and outer muffler plate subassembly.
6. Install the brake block yoke spring plate as well as the
inner and outer brake pad assembly and inner and
outer muffler plate subassembly on the caliper frame.
Guide pin
Guide pin dust cover
Caliper frameBrake block yoke spring plate
Air bleed screw cap
Air bleed screw Caliper
Inner muffler plate subassembly
Alarm plate
Inner brake pad assembly
Outer brake pad assembly
Outer muffler plate subassembly