Iveco EuroCargo (12 to 26 t). Manual

78618

794310

PARKING BRAKE CONTROL
MANUAL DISTRIBUTOR
( V eh ic les ad ap t ed f o r t ow in g )

The device allows performing the safety and parking braking
of tractor and trailer.
The parking braking is mechanical for tractor and pneumatic
for trailer.
The device further allows checking the braking tractor effect.
Such operation is mandatory when the vehicle is parked
under high slope conditions.

The device is connected as follows:

1 -

From four-way protection valve

21 -

To spring cylinders

22 -

To trailer braking triple-control servodistributor.

Figure 49

Air leakage from
exhaust with control
lever:

In unbraking position

In braking position

Difficult control lever
rotation

Check and revise the device, replacing the faulty parts.
Accurately clean the various pieces composing it.

Revise the device and wet all sliding parts.

INCONVENIENCE

POSSIBLE REASON

REMEDY

Faulty valve (5), related seat or sealing
ring

Deteriorated valve (9), pistons (5),
sealing rings and valve (7).

Interference inside the distributor

Diagnostics

URO

ARGO

ECTOR

12-26 t

PNEUMATIC SYSTEM - BRAKES

Base - February 2003

The device, controlled by the two independent tractor
circuits in duplex distributor and spring brake circuit, controls
trailer braking; moreover, a predominance adjusting device is
provided that is placed outside the lower part.

62373

60255

793332

TRIPLE CONTROL SERVODIS-
TRIBUTOR

Predominance adjustment

The apparatus is equipped with a predominance adjusting
device.

The operations to be carried out for adjusting the
servodistributor predominance are performed in the
following order:

- Unscrew screw (2) from silencer body.
- Insert a socket-head screw in the hole through silencer

body and operate on the hexagonal body (1) hole.

- By CLOCKWISE rotating a predominance increase is

obtained.

- By COUNTERCLOCKWISE rotating, a predominance

decrease is obtained.

Diagnostics

Sealing gaskets leakage.
Faulty discharge valve and seat.

Sealing gaskets air leakage.
Worn or faulty pistons and seats.
Yielded springs

Revise the device replacing the faulty parts.
Revise the device replacing the faulty parts.

Revise the device replacing the faulty parts.
Revise the device replacing the faulty parts.
Revise the device replacing the faulty parts.

Air leakage from
exhaust under rest
conditions

Output pressures
different from the
established ones

bar

Figure 50

Figure 51

Figure 52

The apparatus embeds a device that allows performing the
trailer braking even in case of control duct failure.

QUICK DISCHARGE VALVE

71952

Function of the component is discharging the compressed air
from front axle membrane brake cylinders to obtain a quick
unbraking.

INCONVENIENCE

POSSIBLE REASON

REMEDY

URO

ARGO

ECTOR

12-26 t

PNEUMATIC SYSTEM - BRAKES

Base - February 2003

52871

71953

71954

The brake cylinder transmits the force impressed by the
compressed air when operating the brake pedal to the
mechanical service braking device.
In case of anomalies, it is necessary to replace the complete
cylinder.

798510

COUPLING HEADS

- Moderate

- Automatic

Operation

The coupling operation consists in rotating a head with
respect to the other (tractor trailer), guided by a rib that runs
into a suitable guide till it locks. In this phase, seal gasket (C)
pushes downwards the shutoff valve from the other head (A),
by overcoming the resistance of spring (B). A communication
is thereby opened between the two heads guaranteeing their
seal. By uncoupling the heads, the valves are automatically
closed guaranteeing their seal.

The version for ”Moderate” duct is equipped with a red cover
and a safety projection (1), while the version for ”Automatic”
duct is equipped with a yellow cover and a lateral safety
projection (2). The safety projections are used to avoid
coupling errors.

PRESSURE PLUG VALVE

Pressure plugs are inserted into pneumatic system pipings or
tanks,

order

facilitate

connecting

diagnostics

manometers.

Figure 53

Figure 54

Figure 55

Figure 56

794911

MEMBRANE BRAKE CYLINDER
(for disc brakes and drum brakes)

72657

URO

ARGO

ECTOR

12-26 t

PNEUMATIC SYSTEM - BRAKES

Base - February 2003

Air leakage from
exhaust or check
band

Air leakage from
membrane section
supply

Braking force
decrease during
parking brakings

Broken or holed membrane.
Membrane lip breakage.
Check band locking screws loosening.

Deterioration of parts composing the
spring section.

Spring breakage.

Replace the membrane.

Tighten the screw.

Revise the device replacing the worn parts and if necessary
replace the complete cylinder.

Replace the complete cylinder.

Diagnostics

794922

COMBINED BRAKE CYLINDER

The device is composed of two parts: a membrane part for
service braking and a spring part for parking and emergency
braking in case of braking system failure.

Combined

cylinder

emergency

unbraking

device

Repair interventions

Figure 57

Figure 58

Figure 59

36744

36745

When it is not possible to pneumatically supply the combined
cylinder (1) spring section, it is possible to manually unbrake the
vehicle to allow its towing. In order to unbrake the vehicle, it
is necessary to unscrew screw (2) till its end of stroke.

35721

Before detaching the combined cylinder (1) from the vehicle,
perform the manual unbraking procedure of the combined
cylinder by unscrewing screw (2) till its end of stroke.

It is possible to disassemble only the membrane
section.
In case of anomaly of the cylinder spring section, do
not disassemble such part since the above operation
could be dangerous for the operator.

It is advisable, before proceeding with the
disassembly, to accurately clean the external parts
from earth and other impurities that by seeping
inside could damage the cylinder.

INCONVENIENCE

POSSIBLE REASON

REMEDY

URO

ARGO

ECTOR

12-26 t

PNEUMATIC SYSTEM - BRAKES

Base - February 2003

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Iveco EuroCargo (12 to 26 t). Manual - part 182