Iveco Daily Euro 4. Manual — part 214
After rear right wheel bleeding
has been completed (as
signalled by the diagnosis
instrument), close the drain
screw. The procedure will
now be completed.
Call the “BLEEDING”
routine.
Open the rear right wheel
drain screw.
ABS 8/ESP 8 system bleeding procedure sequence
In case of failure of one single
step or the entire bleeding
process, the whole procedure
will have to be repeated.
After front right wheel
bleeding has been completed
(as signalled by the diagnosis
instrument), close the drain
screw and proceed with the
rear right wheel
After front left wheel bleeding
has been completed (as
signalled by the diagnosis
instrument), close the drain
screw and proceed with the
front right wheel.
Open the front right wheel
drain screw.
After rear left wheel bleeding
has been completed (as
indicated by the diagnosis
instrument), tighten the drain
screw and then proceed with
the front left wheel.
Open the front left wheel
drain screw.
Open the drain screw of the
corresponding wheel.
After air bleeding from the braking circuit has been completed, fill with brake fluid up to the top level (do not fill with
oil that has already been used).
NOTE
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- loosen the nut (1);
- connect a weight (A, page 50) to the plate (5) at point
(2);
- tighten the nut (1) at the specified torque and remove
the loads (A and B).
- start up the engine;
784310
Mechanically controlled load sensing
valve (vehicles 35C)
The load proportioning valve automatically adjusts, as a function
of the load acting on the rear axle, the braking torque produced
by the brakes of the axle itself. This valve has the important job,
especially when the vehicle is light without any load, to limit the
braking torque that would otherwise block the rear wheels with
a consequent skidding and jerking of the vehicle.
52386
52385
52387
52388
Figure 40
Figure 41
Figure 42
Figure 43
PERFORMANCE CURVE
A. Inlet pressure (Bar) - B. Outlet pressure (bar)
Ratio = 0.25
LOAD PROPORTIONING VALVE PLATE
Regulation of load proportioning valve on
vehicle
To stop the vehicle from skidding or the wheels from being
locked when braking, you must check the device at regular
intervals and eventually adjust if necessary. This consists in
verifying
the
values
indicated
on
the
plate
(SENZA CODICE) applied on the inside of the bonnet.
!
If there is no plate or if the data is missing, ask the
manufacturer for a duplicate by indicating:
- Vehicle type
- Number of leaf springs
- Vehicle pitch
- Weight of rear axle
- Number of load proportioning valve
The operations are to be carried out in the following order:
- set the vehicle with its rear wheel on a weighing machine
99336914 or on the brake test bench;
- connect the pressure gauges 99372269 or Modus to the
pressure
test
points
upstream
from
the
load
proportioning valve;
- if the pressure gauges are not equipped with a valve for
automatic bleeding, bleed off the air through the
pressure gauges by unscrewing the appropriate ring nuts;
- load the vehicle so as to have a load (B) on the rear axle
divided equally between the right- and left-hand sides of
the vehicle with a tolerance of
±5 kg;
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To check the load sensing valve, all the components of the
braking system must be in full working order. In addition, in the
case of replacing the leaf springs for special versions it is
necessary to install a new rating plate whose values are correct.
784310
Dual mechanically controlled load
sensing valve (vehicles 29L - 35S)
!
Perform the check by gradually increasing the
pressure.
- Once the checks have been completed, verify the
operation of the brakes by testing them.
TABLE OF LOADS FOR ADJUSTING THE LOAD
SENSING VALVE
- with the engine idling and a pressure of 100 bar, shown
on the pressure gauge (3) upstream from the sensing
valve, check that the outlet pressure shown on the
pressure gauge (2) downstream from the sensing valve
corresponds to the values given on the rating plate,
otherwise replace the sensing valve;
- Proceed as follows if the pressure read downstream of
the corrector do not correspond to the values shown in
SENZA CODICE.
- Disconnect the bar (4, SENZA CODICE) from the axle.
- in
addition,
use
the
transmission
lever
(3,
SENZA CODICE) to check that the load sensing valve
stem runs smoothly in its seat, otherwise replace the
sensing valve;
- reconnect the adjustment rod (4, SENZA CODICE) to
the rear axle;
52389
52390
Figure 44
Figure 45
Figure 46
The load sensing valve automatically regulates the braking
torque generated by the brakes of the rear axle according to
the load weighing on the rear axle.
It has the important function, especially when the vehicle has no
load, of limiting the braking torque that would lock the rear
wheels causing the vehicle to skid.
A. Inlet pressure (in bar) - B. Outlet pressure (in bar)
Ratio = 0.15
Adjusting the load sensing valve
52391
This adjustment is similar to that described above,
using the following loads.
TABLE OF LOADS FOR ADJUSTING THE LOAD
SENSING VALVE
3
Model
Load (A)
Load (B)
kg
kg
35C
3.5
1500
40C
3
1500
45C
4
1800
50C semi-elliptic and
double flex. parabolic leaf springs 9
1800
50C single flex. parabolic
leaf springs.
4.5
1800
Model
Load (A)
Load (B)
kg
kg
29L
9
1500
35S
6,5
1500
- Load the vehicle to obtain the loading sequence shown
in the table in fig. 37, equally shared on the rear axle on
the left and right sides of the vehicle with a tolerance of
± 5 kg.
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The devices described below are integrated into three
different types of systems:
ABS SYSTEM FUNCTIONS
Antilock braking system (ABS)
This system comprises an electro-hydraulic modulator and
an electronic control unit mounted on the modulator,
located in the engine bay, four sensors and four phonic
wheels that measure the number of turns of the wheels.
The tendency for one or more wheels, whether front or rear,
to lock, which is detected by the sensors through the pulses
of the phonic wheels, is communicated to the electronic
control unit that, by means of the electro-hydraulic
modulator, independently or simultaneously regulates the
pressure in the hydraulic circuit of the front and rear axles.
Electronic braking distribution device (EBD)
This system acts at a level prior to ABS operation. It ensures
a sensitive control over the tendency of the rear wheels to
lock with respect to the front ones, when braking, by
optimizing the braking force in the different conditions of
load, travel and state of use of the vehicle.
This device substitutes the function of the mechanically
operated load sensing valve. If this device fails, braking takes
place with the same pressure on front and rear brakes.
Electronic Stability Program (ESP) - Option
It monitors the vehicle’s behaviour steadily (both on straight
stretches and bends, when braking or accelerating).
It also monitors the driver’s actions: steering the wheel,
pressing the brake pedal, accelerator position, speed.
It is always active in the background, i.e. the ESP system
compares the actual vehicle ride with the driver’s desired ride
50 times a second. It recognizes dangerous situations before
the driver does.
The system considers the different possibilities of coming into
operation. It brakes on every single wheel separately.
It operates on the engine control system.
FUNCTIONS
INCLUDED
IN
THE
ESP
SYSTEM ONLY
Acceleration drive control device (ASR)
This system prevents driving wheel skid through quick action
on the engine and brakes. It allows the vehicle to set off safely
and fast even on slippery roads or when one driving wheel
is skidding. It also reduces the risk of understeering when you
accelerate too much when cornering.
Engine braking torque control (MSR)
This system avoids driving wheel drag due to the exhaust
brake. It ensures vehicle stability when releasing on slippery
roads (e.g. snow, ice), and assists in keeping the path when
cornering and shifting down, especially on slippery roads. It
requires a slight increase of revs number, through the CAN
line.
Hill holder control (HHC)
This function allows the vehicle to be kept automatically
locked (braked) until the clutch is closet and the driver
subsequently presses the accelerator pedal, thus preventing
undesired vehicle motion.
The function is actuated automatically: the braking situation
is detected by the sensor inside the modulator. When the
brake pedal is released, the vehicle will be kept braked for 2.5
seconds, thus allowing the driver/system to put the gear (and
the vehicle to be started). This ensures safe, easy start with
any incline, regardless of the weight carried.
Hydraulic Brake Assistant (HBA)
The main feature of the HBA function is to recognize an
emergency braking situation followed by “automatic”
increase of vehicle deceleration.
Vehicle deceleration is only restricted to actuation of ABS
control, thus taking the greatest advantage of the grip
between the tyre and the roadbed currently available.
Therefore, ordinary drivers can now achieve braking
distances which only experienced drivers could achieve in
the past.
If the driver reduces the braking intensity, vehicle
deceleration is reduced depending on the reduction of the
force applied onto the pedal.
Therefore, the driver can control deceleration accurately
after overcoming the emergency situation.
The extent of the braking request from the driver
corresponds to the force applied onto the pedal. The force
applied onto the pedal is derived from
measuring the
pressure in the brake pump.
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