Requirements To Be Observed On Cars Fitted With Anti-Lock Braking System; Lock Braking System; Anti-Lock Braking System - Fiat Bravo Service Manual

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REQUIREMENTS TO BE OBSERVED ON CARS FITTED WITH ANTI-LOCK BRAKING SYSTEM

Before carrying out welding work with electric welders, disconnect the connector from the electronic
control unit.
If the battery is removed, after refitting it make sure to tighten the terminals fully.
To replace the electronic control unit, removee the entire hydraulic unit for space reasons and in order
not to damage the internal connector.
Before dismantling the electrohydraulic control unit, disconnect the battery's negative lead.
The entire A.B.S. system must be checked with the Fiat/Lancia Tester whenever the electrohydraulic
unit, an rpm sensor, the electronic control unit or wiring is replaced.
After every intervention on the hydraulic circuit of the A.B.S. or braking system, fill the system with DOT
4 brake fluid, bleed the air out and check that there are no leaks from the connecting points.
The electrohydraulic control unit is supplied filled with DOT 4 brake fluid and the solenoids not sup-
plied. The system is bled and filled with brake fluid in the same way as a conventional braking system,
although it takes longer.
Check that the pipes are not in contact with the bodywork at any point, in order to avoid not only the risk
of damaging the pipe protection, but also the transmission of noise during operation of the A.B.S.
If connecting pipes have to be slackened or removed, leak tests must be conducted on the A.B.S. sys-
tem.
Do not put mineral oil in the brake circuit, as this would damage all the seals.
If it is put in accidentally, the following must be replaced:
- hydraulic unit;
- brake pump;
- calipers.
PRECAUTIONS TO BE OBSERVED DURING REPAIRS INVOLVING COMPONENTS OF THE ANTI-

LOCK BRAKING SYSTEM

After any repair which has involved the electrical system of the anti-lock braking system or the rpm sen-
sors, during either specific interventions or operations for the dismantling and replacement of mechani-
cal parts (for example spring-damper assembly, constant velocity joints, drive shafts and wheel hubs), a
very short road test should be carried out as follows:
1. increase the car speed to over 12 km/h and maintain this speed, in order to allow the electronic con-
trol unit to conduct a dynamic check on the sensors and detect any faults, insecure contacts, incor-
rect positions or the absence of a phonic wheel;
2. after carrying out the above operation, if the warning light does not indicate a fault, continue the test
at a speed of 50-60 km/h for 10 minutes, using the brakes normally but without braking sharply. This
stage of the test enables the electronic control unit to recognize the presence of an incorrect phonic
wheel.
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Braking s y s t e m

Anti-lock braking system

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