Vacuum brake booster
The vacuum brake booster reduces the force on the brake pedal, making it easier to drive. The vacuum amplifier uses a diaphragm, on both sides of which a vacuum is created during normal operation. During braking, air is supplied from one side of the diaphragm, forming atmospheric pressure. Due to the difference in pressure transmitted through the diaphragm, the pusher moves in the direction of rarefaction (vacuum), providing auxiliary force for braking. When the brake pedal is released, air is pumped out of the amplifier cavity through the control valve, creating a vacuum.
Master brake cylinder
The master brake cylinder is used on dual-circuit brake systems. The front right and rear left brakes are actuated by the primary piston, and the front left and rear right brakes are actuated by the secondary piston. The brake master cylinder combines the functions of a standard dual brake master cylinder plus a low brake fluid indicator and brake pressure regulator.
Pressure regulator
The pressure regulator limits the output pressure to the rear brakes after the pressure reaches the limit value in the master brake cylinder. The regulator is used when it is necessary to apply less force to the rear brakes to achieve optimal braking.
Brake fluid level sensor
The brake fluid level sensor located in the brake fluid reservoir turns on the warning light «BRAKE» when detecting a low brake fluid level. Once the brake fluid level reaches the correct level, «BRAKE» goes out.
Fittings and pipelines of the brake system
Connection of pipelines between the brake master cylinder, brake calipers and hydraulic unit is carried out by means of threaded fittings with metric threads.
Brake fluid
Brake technology and in particular disc brakes (hollow pistons that transfer little heat, little fluid in the cylinder, floating calipers that eliminate the need for a relatively large supply of hydraulic fluid in the least cooled part of the wheel), to minimize the risk of «steam locks» even in the case of frequent and prolonged use of the brakes (in the mountains). However, the performance of the brake fluid deteriorates somewhat during the first months of operation due to the slight absorption of moisture. This necessitates the replacement of the brake fluid.
Intervals for changing brake fluid
As the brake pads wear, the level of brake fluid in the reservoir gradually decreases.
There is no need to compensate for this drop, the level will be restored at the next brake pad change. At the same time, the level should not be allowed to fall below the mark of the minimum allowable level.
Mixing two incompatible brake fluids in a hydraulic actuator can lead to significant fluid leaks, mainly due to deformation of the seals.
To prevent this, use only brake fluids that have been tested and approved by the technical department and that comply with SAE J 1703-DOT4.
For optimal vehicle braking performance, RENAULT recommends using low viscosity brake fluids at low temperatures (no more than 750 mm / s at 40°C).
Identification of fittings of the brake system:
A - the shape of the tips of steel or copper tubes;
B - the shape of the threaded recesses in the nodes;
C - fittings with six outer edges of 11 mm.