Load Sensing Valve Replacement; Load Sensing Valve Adjustment On Vehicle - Iveco daily euro 4 Repair Manual

94
REAR AIR SUSPENSIONS

Load sensing valve replacement

Removal
Figure 110
Bleed the system, loosen the screws (3) and disconnect the
pneumatic actuator (2).
Loosen the fastening screws of the load sensing valve (1) and
remove it including the pneumatic actuator (2).
Refitting
Reverse removal operations to perform refitting.
Perform load sensing valve adjustment as shown in the
relevant paragraphs "Load sensing valve adjustment
on vehicle".

Load sensing valve adjustment on vehicle

This device shall be checked and adjusted, if required, at
regular intervals by checking the values indicated on the plate
(Figure 111) located on the internal part of the engine hood.
Should the plate or the relevant technical data be
! missing, ask the manufacturer for a duplicate
specifying the following:
- Vehicle type and wheelbase
- Rear axle weight
- Load sensing valve No.
Figure 111
LOAD SENSING VALVE PLATE
Print 603.93.651
Perform required operations in the following sequence:
- position the vehicle with the rear wheels set on the brake
test bed 99336914;
- connect gauges 99372269 or Modus to pressure control
intakes set upstream and downstream connector;
- should gauges not be fitted with valves for automatic
bleeding, bleed air by loosening the suitable ring nuts
Figure 112
62433
- Loosen nut (1);
- apply 5 kg to plate (3) in point (2);
- start engine;
- disconnect the pneumatic actuator (4);
- with engine running at idle, depress the brake pedal
gradually until obtaining 100 bar pressure read on the
gauge set upstream connector. This value shall be constant
and shall be read on vehicle with load and without load;
- simulate the fully laden condition by lifting completely the
relay lever (3) and the unloaded condition by lowering the
lever completely;
- read output pressure value under both vehicle conditions
(laden and unloaded); obtained values shall comply with
those indicated on the plate, otherwise replace the load
sensing valve;
- operate the relay lever (3) to check whether the load
sensing valve piston is sliding smoothly into its seat,
otherwise replace the load sensing valve;
- reconnect the pneumatic actuator (4);
- load the vehicle to obtain 1500 kg weight on the rear axle
evenly distributed on the right and left side of the vehicle
with ± 5 kg tolerance;
- with engine running at idle and 100 bar pressure read on
the gauge set upstream the connector, check whether the
output pressure value read on the gauge set downstream
the connector is corresponding to the values indicated on
the plate, otherwise replace the load sensing valve;
- stop the vehicle, tighten nut (1) to the specified torque and
remove applied loads.
Perform this check with gradually increasing pressure.
!
To check the load sensing valve, every braking system
component shall be in perfect operating conditions. When
replacing the leaf spring for special set-up, a new plate is
required with properly corrected values.
62577
- when tests are over, check brake performance.
D E 4
AILY URO
62578
Base - March 2006