Vacuum Unit - Fiat Bravo Service Manual

Braking system
Hydraulic system
Bravo-Brava §Pi
D
l^t
TD
33.
VACUUM UNIT
Vacuum gauge with connections for check­
ing operation of vane-type vacuum unit
P4A010D02
Checking operating faults
If the braking system is faulty, before replac­
ing the vacuum unit, the vacuum circuit
should be checked completely in accordance
with the following procedure:
- with the engine off, empty the brake vacu­
um circuit fully by pressing the brake pedal
to the floor several times;
- fit the vacuum gauge 1895899000 (3) be­
tween the one-way valve located on the
vacuum unit (1) and the servo unit con­
necting pipe (2) (as shown in the drawing
opposite);
- start the engine; after running the engine at
idling speed for 20 seconds, the vacuum
reading on the vacuum gauge (3) should
be over 0.6 bar.
If the vacuum is under 0.6 bar, the servo unit
connecting pipe (2) should be disconnected
and the free end should be plugged with the
special plug (4).
Re-start the engine; after running the engine
at idling speed for 20 seconds, the vacuum
reading on the vacuum gauge should be over
0.6 bar.
If it is, the fault should be sought in the air
circuit or the servo unit.
If not, the vacuum unit is faulty and should be
replaced.
10
Publication no. 506.670