Dacia SuperNova (engine E7J). Service manual — part 62
30
GENERAL
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BRAKING SYSTEM DIAGNOSTIC
II.
CONSTANT EFFECT AT BEHAVIOUR
EFFECTS
Brakes not accomplishing the
required braking distance
Vibrating brakes
When braking, the vehicle ( front
part) is left/right deviating
Braking
Heating brakes
POSSIBLE CAUSES
- Non-un iform worn b rake lin ings
(backing off);
- Brake linings slightly greased;
- Springs with modified characteristics.
- Brake disks with high wobbling;
- Inconstancy brake disks width;
- Particles abnormal deposit on brake disks
(oxidation between linings and disk).
- Front axle suspension, steering (to be
checked);
- Stuck piston;
- Tires – wear, inflation pressure;
- Rigid duct narrowed (flattening).
- Stuck piston;
Automatic adjustment : hand brake cable very
tighten.
REMARK :
Automatic recovering is performed by
means of the brake pedal, if there is no ab-
normal tension in the hand brake cable
when released (hand brake released).
- Return spring.
- Insufficient hydraulic stroke of the brake
pump, not allowing the return at rest of
the brake pump pistons ( brake pump
remaining under pressure);
- Stuck pistons or hardly returning;
- Rigid duct narrowed (flattening);
- Defective adjustment of the hand brake
control.
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GENERAL
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BRAKE CONNECTIONS AND SEWERAGE
The sewerage connection between the brake pump, brake calipers, pressure limiter is
performed by means of the threaded connections with METRIC PITCH.Therefore it is
important to use only original spare parts, recommended in the Spare Parts Catalogue,
specific for this type of vehicle.
Spare parts identification
The cupping shape of the steel ducts (A)
The shape of the threaded lengths on
parts (B)
Connections of ducts (C)
A
B
C
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GENERAL
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BRAKE FLUID
PERIODICITY OF THE BREAK FLUID CHANGE
The manufacturing conception of the brakes equipping the Dacia vehicles, especially
the disks brake type (F 54 inner empty pistons, low quantity of fluid in the cylinders,
sliding calipers avoiding existence of a fluid reserve in the less cooled area of the wheel)
enable the maximum rejection of fluid vaporization risk, even in case of intensive using of
brakes (mountain area).
The current brake fluids are subject in all cases to a slight degradation during the first
months of use by a slight humidity absorption series (see the Vehicle Warranty and
Maintenance Booklet, for brake fluid change)
LEVEL COMPLETION
The wear of brakes pads and shoes generate a gradually diminution of brake fluid level
in its reservoir. It is useless to compensate this diminution, because the level will be re-
stored in the moment of next changing the brake pads and shoes. Obviously, in the mean-
time, the level of brake fluid in reservoir must not go down bellow the minimal mark.
HOMOLOGATED BRAKE FLUIDS
The mixture in the braking circuit of two non compatible brake fluids may leads to loss
important risks mainly due to gasket damage
In order to avoid such risks, it is obligatory to use brake fluids checked and approved by
our laboratories and which are according to Norm SAEJ 1703, DOT 4.
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GENERAL
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BRAKING CIRCUIT PURGING
AIR ELIMINATION FROM THE HYDRAULIC
CIRCUIT (PURGING)
The air existence in the hydraulic circuit may be noticed by an elastic displacement of
the brake pedal, sometimes even, close to the floor. This fact is more evident with the
engine stopped.
GENERAL 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).
During the purging, the brake fluid from the reservoir must not go down bellow the
minimal level marked on the reservoir.
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 transparent plastic tube and brake fluid for completion.
NOTE
The brake fluid resulted after performing the purging operation, IS NOT TO BE
RE-USED but only after 48 hours, in order to avoid air-bubbling generation 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 brake fluid
and proceed as follows:
- press the brake pedal slowly, dismount the purging screw, maintaining the full
stroke of the pedal, then tighten the screw and slowly release the brake pedal. Repeat the
same procedure until complete cease of air bubbles. Proceed in the same way also for the
other purging places.(take into consideration the existence all the time of the brake fluid in
the reservoir)
Observation:
Before beginning the purging procedure, dismount the I.C.P. indicator from the pump,
which shall be remounted at the end of the operation.
It is important to observe the following sequence of the purging places:
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