Citroen Xantia

since 1993 of release

Repair and car operation

Brake system

Specifications

General parameters

System type

Two independent hydraulic contours (forward and back). ABS on some models. Disk lobbies and back brake mechanisms. Pressure in brake contours is provided with the main hydraulic system (see. Head Uniform hydraulic system). The parking brake has a hummock drive on forward wheels.

Brake mechanisms of forward wheels

Type	Disk, ventilated, with a 1-piston floating support
Diameter of a brake disk, mm
All models, except petrol with the RFY series engine (16 valves)	266.0
The petrol models equipped with the engine of the RFY series (16 valves)	283.0
Thickness of a brake disk, mm
All models, except petrol with the RFY series engine (16 valves)
• New disk	20.4
• Minimum admissible value	18.5
The petrol models equipped with the engine of the RFY series (16 valves)
• New disk	22.0
• Minimum admissible value	20.0
The maximum admissible difference in thickness of disks, mm	0.1
Maximum admissible lateral palpation, mm	0.05
Working surface of a frictional slip, cm²
All models, except petrol with the RFY series engine (16 valves)	41
The petrol models equipped with the engine of the RFY series (16 valves)	48
Thickness of new frictional slips, mm
All models, except petrol with the RFY series engine (16 valves)	12.0
The petrol models equipped with the engine of the RFY series (16 valves)	11.0
Minimum admissible thickness of frictional slips, mm
All models, except petrol with the RFY series engine (16 valves)	3.0
The petrol models equipped with the engine of the RFY series (16 valves)	2.0
Material of frictional overlays of Bezasbestovye of AVEH	949

Brake mechanisms of back wheels

Type	Disk (with continuous disks), with 2-поршнеым the fixed support
Diameter of a brake disk, mm	224.0
Thickness of a brake disk, mm
• New disk	9.0
• Minimum admissible value	7.0
The maximum admissible difference in thickness of disks, mm	0.1
Maximum admissible lateral palpation, mm	0.05
Working surface of a frictional slip, cm²	17
Thickness of new frictional slips, mm	11.4
Minimum admissible thickness of frictional slips, mm	2.0
Material of frictional slips	Bezasbestovye AVEH

Efforts of a tightening of carving connections, Nanometer

Bolts of fastening of an anchor bracket of a support of the forward brake mechanism	105
Directing bolt of a support of the forward brake mechanism	50
Bolts of fastening of a back support	47
Bolts of fastening of a brake pedal to a partition	15
Bolts of fastening of the valve of management	20
Lock-nuts of a regulator of the parking brake	20
Bolt and nut of fastening of a rod of management of transfers	17
Shtutsernye of connection of brake tubes	8
Nuts of fastening of the gidroklapanny ABS block	22
Bolts/hairpin of fastening of wheel ABS sensors	8
Bolts of fastening of wheels	90

General information

All models are equipped with 2-planimetric brake system with a drive from the main hydraulic system of the car (see. Head Uniform hydraulic system) by means of the valve of the management playing a role of the main brake cylinder in brake systems of usual type. Pressure upon forward brake mechanisms moves directly from the main hydraulic system (through a pressure regulator). The contour of brake mechanisms of back wheels is connected to a hydraulic path of a back suspension bracket. At such scheme of distribution of pressure the main brake effort is the share of forward wheels of the car while the effort developed by back brake mechanisms depends on extent of loading of the car.

The pedal of a foot brake is mechanically connected with assembly of the valve of management.

Forward brake mechanisms are equipped with 1-piston supports of floating type influencing disks of ventilated type.

In back brake mechanisms the fixed supports equipped with two pistons, providing a clip of blocks to continuous disks are used.

The parking brake has a mechanical hummock drive and influences forward wheels of the car. The control lever is located the parking brake on a floor between forward seats.

The system of anti-blocking of brakes (ABS) is included into a standard complete set of some models and can be established in addition on any models. The design and a principle of functioning of system are described in the section System of anti-blocking of brakes (ABS) - the general information.

Precautionary measures

As a working body in hydraulic system of Citroёn Xantia cars mineral LHM liquid of darkly green color is used. Application of hydraulic liquids of any other type is fraught with failure of rubber sealants and connecting hoses of components of system. Store hydraulic liquid in tightly closed container.

In extreme situations use as a working body in hydraulic system of SAE 10 or SAE 20 engine oil is allowed, however in such cases on arrival to a repair/parking place the hydraulic path should be emptied and at the first possibility is filled with standard LHM liquid.

After removal from system of liquid of a doubtful origin the hydraulic path should be washed out by special structure which it is possible to get in firm Citroёn company service centers. Having pumped over system, leave its filled with flushing structure which should be used throughout about 1000 km (600 miles) run. Then it is necessary to empty and fill system with standard hydraulic LHM liquid again. In case of failure of rubber consolidations as a result of use of the non-standard liquid, all damaged components are subject to replacement. It is necessary to charge performance of this work to specialists of car repair shop.

As replaceable components it is necessary to use only firm details of production of the Citroёn company which are usually painted in white or green color and are intended for use in contact to LHM liquid.

One of the basic rules which should be observed at service of components of a hydraulic path, the most careful observance of purity is. Carefully wipe components subject to a detachment and surfaces adjoining to them. All opened after removal of a component of connection at once cork in order to avoid hit in system of dirt and extraneous subjects.