Suspension - Steering - Brakes

SUSPENSION

IMPORTANT:It is essential to observe the safety and cleanliness instructions described in the after-sales brochure "precautions and recommendations".

Overview

The suspension is hydraulic.

The suspension is self-adaptive.

There are 2 types of suspension:

• 3rd generation Hydractive, or Hydractive 3.
• 3rd generation Hydractive +, or Hydractive 3+.

Application:

Specifications

The suspension fluid (LDS: Liquide Direction Suspension) is orange and 100% synthetic.

The LDS suspension fluid is supplied in 1 litre containers (Part No. PR: 9979.69).

Important:The LDS suspension fluid is not miscible with LHM hydraulic fluid.

The Hydro Block

The Hydro Block (integrated electronic unit, core of the suspension system) consists of the following components:

• an electric motor to drive the hydraulic pump,
• a 5-piston axial hydraulic pump,
• an anti-pulsation accumulator and flow regulator,
• 4 solenoid valves: 2 per axle, 1 for supply (raising the vehicle), 1 for exhaust (lowering the vehicle)
• an electronic suspension control unit,
• 2 non-return valves,
• 6 hydraulic fluid filters: upstream and downstream of the solenoid valves,
• a pressure relief valve.

1. 1
   Suspension sphere (saucer type)
2. 2
   Hydraulic damper
3. 3
   Diaphragm
4. 4
   Safety pre-cut

The suspension spheres are of the "saucer" type.

The suspension spheres use a multi-layer diaphragm, giving them an unlimited service life.

A safety pre-cut is made in the upper part of the sphere.

In the event of bursting from overpressure, the pre-cut prevents metal fragments from being ejected.

IMPERATIVE: It is forbidden to recharge or repair a "saucer" sphere.

Specifications:

Important: The number stamped on the pneumatic block is the component reference number, not the spare part number.

Operation

The Hydractive 3 suspension has 2 automatic modes:

• motorway position: vehicle height lowered by 15 mm as soon as 110 km/h,
• degraded road position: vehicle height raised by 13 mm up to 90 km/h.

To determine the most suitable vehicle height, the Hydractive 3 Integrated Hydro-electronic Unit uses the following information:

• vehicle speed,
• front and rear vehicle heights.

The Hydractive 3 + suspension has 3 automatic modes:

• motorway position: vehicle height lowered by 15 mm as soon as 110 km/h,
• degraded road position: vehicle height raised by 13 mm up to 90 km/h,
• switching to "comfort" or "dynamic" suspension: variation of suspension firmness.

To determine the most suitable vehicle height and suspension firmness, the Hydractive 3 + Integrated Hydro-electronic Unit uses the following information:

• vehicle speed,
• front and rear vehicle heights,
• steering wheel rotation speed,
• steering wheel angle,
• longitudinal vehicle acceleration,
• lateral vehicle acceleration,
• suspension travel speed,
• accelerator throttle movement.

A vehicle height can be selected by pressing the momentary control buttons inside the vehicle.

There are 4 positions:

• high position: for changing a tyre, cancelled above 10 km/h,
• off-road position: for crossing obstacles, cancelled above 40 km/h,
• normal position: reference height,
• low position: for loading or hitching a trailer.

Important: Driving in low position is prohibited.

The switching thresholds to "dynamic" suspension can be lowered by pressing the control button inside the vehicle.

FRONT AXLE

Front axle of MacPherson-type design, with independent wheels, suspension spheres and cylinders.

REAR AXLE

Rear axle with trailing arms, independent wheels, suspension spheres and cylinders.

The rear crossmember consists of:

• A crossmember body made of aluminium extrusion,
• Two aluminium shell-cast brackets integrating the rebound and bump stops.

The brackets are welded to the crossmember body.

The assembly is attached at 4 points to the body.

VEHICLE HEIGHT

Vehicle height

Key:

• H1 - Measurement between the ground and the measuring point on the front subframe
• H2 - Measurement between the ground and the measuring point on the rear crossmember bracket
• R1 - Loaded front wheel radius
• R2 - Loaded rear wheel radius
• L1 - Distance between wheel centre and measuring point on the front subframe (L1 = R1 – H1)
• L2 - Distance between wheel centre and measuring point on the rear crossmember bracket (L2 = H2 – R2)

Front axle (A)

Note: Vehicle at kerb weight: empty vehicle, all fluids full, correct tyre pressure.

Rear axle (B)

Note: Vehicle at kerb weight: empty vehicle, all fluids full, correct tyre pressure.

WHEEL ALIGNMENT

The suspension is hydraulic: checks can be carried out at reference trim or at kerb weight.

Front axle geometry

Note: Vehicle at kerb weight: empty vehicle, all fluids full, correct tyre pressure.

Note: Vehicle at kerb weight: empty vehicle, all fluids full, correct tyre pressure.