brake DACIA SUPERNOVA 2004 Owner's Manual

30
GENERAL
30 - 14
BRAKING CIRCUIT PURGING
AIR ELIMINATION FROM THE H YDRAULIC
CIRCUIT (PURGING)
The air existence in the hydraulic circuit may be noticed by an elastic displacement of
the bra ke pedal, sometimes even, close to the floor. T his fact is more e vident with the
engine stopped.
GE NERA L RECOMMENDATIONS
Always use for completion or total changing, the brake fluid Norm SAE J 1703 , DOT 4.
In case of changing the brake fluid, it is necessary to wash the system with one liter of
industrial alcohol (diluted). Du ring the purging, the brake fluid from the reservoir must not go down bellow the
minimal level marke d on the re servoir.
To perform the operation, one person will stay on the driver place, to push the brake
pedal and the other one will perform the purging (bleeding) at the wheels using a 500 ml
vessel, a tra nsparent plastic tube and brake fl uid for completion.
NOTE
The brake fluid resulted after performing t he purging operation, IS NOT TO BE
RE-USED but only after 48 hours, in order to avoid air-bubbling ge neration on the
hydraulic circuit which shall have as effect an elastic brake pedal.
WORKING PROCEDURE
Place on the purging screw, a transparent tube with its end in a vessel with bra ke fluid
and proceed as follows: - press the brake pedal slowly, di smount t he purging screw, maintaining the full
str oke of the pedal, then tighten the screw and slowly re lease the brake pedal. Repeat the
same procedure until complete cease of air bubbles. Proceed in the same way also for the
other purgi ng places.(take i nto c onsideration t he existence all t he t ime of t he bra ke fl uid i n
the reservoi r)
Observation:
Before beginning the purging procedure, dismount the I.C.P. indicator from the pump,
which shall be remounted at the end of t he operation.
It is important to observe the fol lowing sequence of the purging places:
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30
GENERAL
30 - 15
BRAKING CIRCUIT PURGING
PROCEDURE IN PARALLEL SYSTEM
1.,6. Main cylinder with I.C.P. i ncorporated
2. Left rear wheel brake cylinder
3. Right rear wheel brake cylinder
4. Caliper of front right wheel
5. Caliper of front left wheel WORKING CONDITIONS
The vehicle is on wheels.
If the fuel tank is e mpty, place on the rear bench of the vehicle one or two persons to
enable the possibility of the circ uit opening (the passing of a larger fluid flow through the
brake limiter).
CHECKING THE BRAKE SYSTEM SEALING
Af ter purging the front and rear circuits, check if t he level of brake fl uid in reservoi r is
w ithin the minim a nd m axim range, than press t he bra ke pe dal, then during about 30
seconds, no pedal displacement must be noticed.
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GENERAL
30 - 18
PRELIMINARY CHECKING
Due to the geometr ic conception of the front axle, the modificati on of one of one-
si de angles (castor, camber, ball joint) has no major impact on the value of other side
angles (the parallelism being the one directly influenced). The m odification of t hese a ngles doe s not oc cur duri ng vehicle exploitation, but onl y as
a consequence of a vehicle accident.
It is import ant to observe the following sequence : - placing the vehicle on rotating plates;
- braked vehicle
- suspension checking for pl acing the vehicle at its free height;
- establishing the steering centra l point and steeri ng box blocking.
- attachment of the optical devices on the vehicle, observing the manufacturer
instructions.
REPARTITION CHECKING AND ADJUSTMENT
Check the “ X” dimension symmetry of
the connecting rods.
Reading of t he “ A” value on the scale.
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FRONT BEARING ELEMENTS
31 - 1
CHARACTERISTICS
The front axle is composed of two joint half axles with independents wheels, designed for the
suspension type Mc.Pherson.
The joints of front half axle arm are done by means of an elastic bear ing (chassis side) and
by means of a suspension ball joint (wheel side)
The transmission of the motion to the wheels is done by means of two planetary axles, not
equal, with homocinetic tripod joints.
The wheel hub is assembled in the steering knuckle by means of a preset and sealed
bearing. The brake disks are aerated.
Tigh tening moments (daNm)
Wheel attachment screw 7,5
Suspension arm shaft nuts 7,5
Attachment nut of the ball joint screw 5,5
The nut of the attachment screw of the steering
knuckle with the shock absorber 7,5
Transmissio n nut 21,0
Steering ball joint nut 4,0
The attachment anti roll bar nut 2,5
The connecting strap screw 2,7
The attachment screw of the suspension ball joint on the arm 7,5
The attachment screws of the disk on the hub 2,5
Aux.connecting rod- assembled connecting rod end stop nut 5,0
Assembled connecting rod end- rack joind body 5,0
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FRONT BEARING ELEMENTS
31 - 6
BRAKE GASKETS
NOTE
In order to maintain the brake efficiency,
the replacement of the brake pads shall be
made only in complete kit.
Never fit brake pads of diffe rent makes
and different qualities .
DISMOUNTING
Lift t he vehicle by means of a two columns
elevator;
Dismount the front wheel;
Disconnect the wear sensor wire;
Dismou nt : - the safety of the wedges (1);
- the wedges, by sliding them.
Detach the caliper assembly from the fork
together with the flexible hose;
Remove : - the elastic blades - the brake pads
Remount :- the brake pads their places in the fork;
- the elastic blades;
- the caliper;
- the wedges and their locks.
Reconnect the wear sensor wire.
Pr ess several times the brake pedal.
Mount the wheels.
Get down the vehicle from the elevator the
ground. NOTE
It
is forbidden to push the brake pedal
after the calipers were dismounted from
the fork. If the brake pads are not fully used but
on their friction surface, especially i n the
middle pad c hannel, there are material
traces, i t i s recommended t he cleaning of
these surfaces in order to avoid the noise
when braking.
REMOUNTING
Push the c aliper pi ston by means of the
FR 500 s pecial t ool.
SPECIAL TOOLS
FR 500 Pushing piston device
FR 500
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FRONT BEARING ELEMENTS
31 - 7
BRAKE CALIPER
DISMOUNTING
Lift the vehicle by means of a two columns
elevator.
Dismount the wheel.
Disconnect the wear sensor wire
Drain the brake fluid from the reservoir
Remove the locks and the caliper wedges;
Unscrew the rigid duct screw from the brake
flexible hose and detach the caliper assemb ly.
NOTE
If it is necessary to dismount the
caliper fork, unscrew the two attachment
s crews M 12.
When remounting the fork, replace the
Grower washers, tighten the screws at the
r equired moment of 6.5 daNm then seal
them with FIXAMED R 58. REPAIR
ING
Dismount the protection gasket.
Extract the piston using a wooden wedge and
a compressed air source. Remove the sealing gasket from its seat in the
caliper groove by means of a steel blade. Clean with alcohol the parts, replace t he
damaged ones, mounting being performed in the
dismounting reverse order, after previously all
parts have been oiled with brake fluid.
NOTE
Before remounting to t he wheel, c heck
the sealing of the caliper assembly.
TIGHTENING MOMENTS (daNm)
Wheel nuts 7,5
Rigid duct on front flexible screw 1,5
Purging screw 1
Flexible hose - caliper 2
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FRONT BEARING ELEMENTS
31 - 8
BRAKE CALIPER
REMOUNTING
Perform the dismounting operations in the reverse order plus the following operations : - fill the caliper with brake fluid in order to facilitate the brake system purging;
- purging the brake system.
BRAKE CALIPER SEALING CHECKING
Connect to the caliper, a pressure gauge attached to a compressed air source.
P lace a wooden wedge in order to block the piston.
Create a 0,3 bars pressure in the caliper.
Dip the caliper into a vessel with alcohol.
Move the piston several times to remove the air from the sealing gasket seat.
Check the sealing of the brake caliper at various pressu res, without exceeding the pressure of 2 bars.
If the brake shows air leaks by the piston, perform at its dismounting.
Replace the piston, the ga sket, or the caliper body, as the c ase stands.
Perform again the sealing test.
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FRONT BEARING ELEMENTS
31 - 9
DISMOUNTING
Lift the vehicle by means of a two col-
umns elevator.
Dismou nt :
- the wheel;
- the two attachment screws M 12 ( B)
of the brake disk assemb ly on the steering knuckle;
- the brake pads;
- the t wo sunk screws attaching t he
disk on the hub. BRAKE DISK
The brake disks can be not rectified.
A bigger wear or an important mark on the brake disk braking surfaces impose obligatory its
replacement.
- The minimal accepted thickness : 19 mm
- The maximum accepted axial deviation 0,1 mm on a diameter of F 215.
TIGHTENI NG MOMENTS (daNm)
steering nuckle 6,5
Disk attachment screw on the hub 2,5
Front wheel steering knuckle nut 21
Wheel screws 7,5
Before remounting, check:
- the wear of the flexible hose;
- the wear of the bra ke pa ds and
replace them if necessary. REMOUNTING
Remount :
- the disk on the hub by means of the two
sunk screws M8 and tighten them to the required
moment; - the brake disk assembly on the steering
knuckle, tightening the M 12 screws at t he
required moment. Press the brake pedal several times, in order
to bring the piston in contact with the brake pads.
NOTE :
In case of replacing the brake disk it is ab-
s olutely necessary to replace the brake pads.
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FRONT BEARING ELEMENTS
31 - 10
SPECIAL TOOLS
Hub disk extractor PF600
Ball joint extractor PF476
DISMOUNTING
Disconnect the battery.
Lift the vehicle by means of an elevator with
two column. Dismou nt :
- the wheel
- the brake disk assembly together with
the flexible connection;.
- the transmission gear nut.
- the brake disk a ssembly by means by
means of the PF 600 extractor.
Continue by dismounting t he steering
knuckle, observing the operations sequence: - dismount the steering ball joint nut;
- depre ss the steeri ng ball joint by
means of the PF 476 extractor;
- dismount the t wo screws that attach
the steering knuckle on the shock absorber; - dismount the attachment screws that
attach the steering ball joint – steering knuckle;
- detach the steering knuckle.
TIGHTENING MOMENTS (daNm)
Wheel attachment screw 7,5
Steering ball joint nut 3,5
Transmission nut 21
Attachment fork screw on steering knuckle 6,5
The screw nut of the steering knuckle
attachment with the shock absorber leg 7,5
The attachment screw nut of the ball
joint with the steering knuckle 5,5
STEERING KNUCKLE
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REAR BEARING ELEMENTS
REAR AXLE
TIGH TENING MOMENTS (daNm)
Wheel attachment screw 7.5
Axle attachment nut 8.5
S hock absorber bottom attachment nut 8.0
Re ar axle arm elastic bushing axle nut 12.0
Br ake rigid piping connection screw 1.5
Purgi ng screw 1.0
DISMOUN TING
Lift the vehi cle on two column s
elev ator.
Dismo unt the tw o rear whee ls.
Drain the braking sys tem.
Dis mou nt th e bra ke dr um s.
Disconnect the two-connector screws of
the brake rigid piping of the brake cylinder.
Loosen the connections of the
secondary cable from the hand brake levers
and remove the cable from the brake plates.
Dismou nt th e ope rating rod supp ort of
the brake limiter from the right side axle
arm, after previously both arms protectors
have been dism oun ted . Di
smount the lower attachment screws (A)
of the shock absorber with the re ar axle. Push upward the shock absorbers.
Di smount the springs.
Dism ount the conn ecting screws (B)
between the rear axle arms and the chassis. Dismount completely the rear axle.
Check the elastic bushings condition.
S
PECIAL TOOLS
DENOMINATION CODE
Drum cover pliers R0 441
Hub extractor PF 600
Dismounting pliers for shoe s
return spr ing FR03
S hoes protectors FR09
P liers for ma intaining brake
cylinders pistons FR05A
Dynamometric wrench MOT30
Com paring dial gauge R054A
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