Dacia SuperNova (engine E7J). Service manual — part 77
MECHANICAL ELEMENTS CONTROL
37
BRAKE PUMP REPAIRING
The operation is performed after dismounting the central pump off the vehicle.
DISMOUNTING
Dismount the brake fluid reservoir, recover-
ing the two sealing gaskets of the brake fluid res-
ervoir.
Dismount the transducer and the purging
screw.
Clamp a 3,5 mm drill in the vice.
Introduce the drill in the elastic pin
Rotate and draw the pump until the pin is ex-
tracted;
Extract the secondary piston elastic pin, in the
same way.
Remove from the pump:
- the Pp primary piston assembled ;
- the primary piston return spring;
- the Ps secondary piston assembled;
- the secondary piston return spring
Wash the parts with alcohol and blow them
with compressed air.
Check:
- the pump bore
- the pistons gaskets
- the springs
The parts of the “ primary piston” Pp and those of the “ secondary piston” Ps, cannot be repaired.
In case one of these parts is damaged, replace the whole kit ” primary piston” and “secondary
piston”, primary piston return spring, secondary piston return spring.
REMOUNTING
Before remounting, the parts and the pump bore will be lubricated with brake fluid.
Mount the “ secondary piston” and “primary piston “ assembly.
Compress the pistons and introduce the elastic pins; the pins slot shall be oriented towards the
pump attachment flange.
Mount the purging screw;
Purge the brake circuit and remount the ICP transducer.
BRAKE PUMP
37 - 5
MECHANICAL ELEMENTS CONTROL
37
MASTER VAC 7 SERVO MECHANISM
The ” Master-Vac 7” servobrake is a brake booster with the objective of reducing the driver
effort on the brake pedal.
ATTENTION
The servobrake cannot be repaired.
The only items of the servobrake which are to be replaced are the air filter and the retainer
valve.
DISMOUNTING
Close the pipe between the brake fluid reservoir and the clutch transmitter cylinder by means
of the MOT 453 device.
Drain the liquid out of the reservoir.
Disconnect from the reservoir the feeding pipe of the clutch transmitter cylinder.
SERVOBRAKE
OBSERVATION
In case one circuit is damaged, the pedal stroke shall be longer, the braking being
done only by the circuit still working.
37 - 6
TIGHTENING MOMENTS (daNm)
Brake pump nut on servobrake
1,3
Servobrake attachment nut on the cowl panel
2,0
MECHANICAL ELEMENTS CONTROL
37
REMOUNTING
Before remounting, check:
- the adjustment of the main cylinder
stroke, which is obtained by acting on the pushing
rod nut in order to obtain value X= 9mm,
between the pushing rod end and the rest surface
of the main cylinder.
- the adjustment of the coupling fork on
the brake pedal side, which is obtained by
unscrewing the lock nut E and by acting on the
coupling fork in order to obtain the value L =
117 + 0,5 mm.
For remounting, perform the dismounting
operations in the reverse order.
Purge the brake circuit.
Mounting the I.C.P. transducer.
Mount the electric connector at the I.C.P.
Detach the four rigid brake ducts from the
main brake pump.
Disconnect the electrical contact from ICP
transducer.
Dismount the main pump from the
servobrake.
Disconnect the suction hose off the
servobrake.
SERVOBRAKE
37 - 7
Dismount :
- the connecting shaft ( 1 ) between the
coupling fork and the pedal ;
- the attachment nuts of the servobrake
on the cowl panel.
Dismount the servobrake .
MECHANICAL ELEMENTS CONTROL
37
The tightness of the servobrake is checked on the vehicle, with the hydraulic
circuit under operation.
Connect the vacuum meter between the servobrake and the inlet collector by means of a “ T
” type connector.
The connecting hose of the vacuum meter shall be as long as possible.
Start the engine and let it idle run for 1min.
Block the air suction hose by means of the MOT 453 device.
Stop the engine.
If air suction lowers with more than 33 mbar (25Hg) in a 15 seconds period, it means there
is a loss at the retainer valve (replace the valve) or at the servobrake membrane (replace the
servobrake)
Dismount the MOT 453 device
Dismount the vacuum hose
Reinstate the connection between the servobrake and the inlet collector by means of the
vacuum hose.
TIGHTNESS CHECKING
SERVOBRAKE
SPECIAL TOOLS
Shutter
MOT 453
37 - 8
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