Brake System Main Components; Vacuum Pump; Vacuum Servo Brake - Iveco daily euro 4 Repair Manual

D E 4
AILY URO
BRAKING SYSTEM MAIN COMPONENTS
790530

Vacuum pump

Figure 35
This is the component which generates a reduction in
pressure for operation of the servo brake.
Diagnostics
TROUBLE
Oil leakage from cover
Poor efficiency
794101

Vacuum servo brake

Figure 36
Print 603.93.651
109121
POSSIBLE CAUSES
Incorrect driving torque
between power reducer and
engine.
Cover seal surface
completely flat.
Broken seal between pump
and engine.
Excessive backlash between
the blades and sliding surfaces.
Bad sealing of connecting pipes
or uni-directional valve.
Insufficient lubrication.
32279
The figure shows the version for vehicles with engine F1C.
As regards the vehicles with engine F1A/F1C, the vacuum de-
vice is incorporated into the vacuum oil pump unit.
CURE
Lock screws to correct driving torque indicated in appropriate
table.
not Check the seal surfaces, replace any defective parts or place
them on a flat surface.
Replace seal.
Replace blades, or the entire pressure reducer.
Check the seal and eventually replace the connecting pipes or
replace the uni-directional valve.
Carefully clean the oil pipes.
This is a device which increases the force applied by the pedal
and consists of two main components:
- a power reducer pneumatic section;
- an hydraulic section (master cylinder and brake liquid
tank).
The servo brake is manufactured in such a way that in case
the pneumatic section fails, the brakes can still work. In this
case the braking action is obtained by one master cylinder.
HYDRO-PNEUMATIC SYSTEM - BRAKES
55
Base - March 2006