12. 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 the Head Uniform hydraulic system). The parking brake has the 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 RFY series engine (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 RFY series engine (16 valves) |
|
|
• New disk |
22.0 |
|
• Minimum admissible value |
20.0 |
|
The maximum admissible difference in thickness of disks, mm |
0.1 |
|
Maximum admissible side beating, mm |
0.05 |
|
Working surface of a frictional slip, cm 2 |
|
|
All models, except petrol with the RFY series engine (16 valves) |
41 |
|
The petrol models equipped with the RFY series engine (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 RFY series engine (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 RFY series engine (16 valves) |
2.0 |
|
Material of frictional slips Bezasbestovy AVEH |
949 |
Brake mechanisms of back wheels
|
Type |
Disk (with continuous disks), with the 2-porshney 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 side beating, mm |
0.05 |
|
Working surface of a frictional slip, cm 2 |
17 |
|
Thickness of new frictional slips, mm |
11.4 |
|
Minimum admissible thickness of frictional slips, mm |
2.0 |
|
Material of frictional slips |
Bezasbestovy AVEH |
Efforts of tightening of threaded connections, Nanometer
|
Bolts of fastening of an anchor bracket of a support of the forward brake mechanism |
105 |
|
The 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 the regulator of the parking brake |
20 |
|
Bolt and nut of fastening of a rod of management of transfers |
17 |
|
Nipple connections of brake tubes |
8 |
|
Nuts of fastening of the hydrovalvate 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 the 2-circuit brake system with the drive from the main hydraulic system of the car (see the 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 (via 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 the 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 the mechanical hummock drive and influences forward wheels of the car. The control lever is located the parking brake on a floor between front seats.
The system of anti-blocking of brakes (ABS) is included in a basic equipment of some models and can be established in addition on any models. The design and the 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 the Citroyon Xantia cars mineral LHM liquid of darkly green color is used. Use of hydraulic liquids of any other type is fraught with failure of rubber sealants and connecting hoses of components of system. You store hydraulic liquid in hermetically closed container. |
In extreme situations use as a working body in hydraulic system of the SAE 10 or SAE 20 engine oil is allowed, however in such cases on arrival to the place of the repair/parking the hydraulic path has to be emptied and at the first opportunity is filled with standard LHM liquid.
After removal from system of liquid of a doubtful origin the hydraulic path has to be washed out by special structure which it is possible to acquire in company service centers of the Citroyon company. Having pumped over system, leave its filled with flushing structure which has to be used throughout about 1000 km (600 miles) of a run. Then the system should be emptied and filled with standard hydraulic LHM liquid again. In case of failure of rubber consolidations as a result of use of non-standard liquid, all damaged components are subject to replacement. Performance of this work should be charged to specialists of car repair shop.
As replaceable components it is necessary to use only company details of production of the Citroyon company which are usually painted in white or green color and are intended for use in contact with LHM liquid.
One of the basic rules which have to be observed at service of components of a hydraulic path is the most careful respect for purity. Carefully wipe the components and surfaces adjoining to them which are subject to a detachment. All connections at once cork the removals of a component opened later in order to avoid hit in system of dirt and foreign objects.