ABS regulation function

D42.30-0022-06

"Rear right" brake circuit with solenoid valves in rest position

A1 Hydraulic unit

ASV ABD intake valve

AVHL ABS solenoid valve, pressure reducing, rear left

AVHR ABS solenoid valve, pressure reducing, rear right

AVVL ABS solenoid valve, pressure reducing, front left

AVVR ABS solenoid valve, pressure reducing, front right

D Damper chamber

EVHL ABS solenoid valve, pressure holding, rear left

EVHR ABS solenoid valve, pressure holding, rear right

EVVL ABS solenoid valve, pressure holding, front left

EVVR ABS solenoid valve, pressure holding, front right

RFP Return pump

RVR Non-return valve

SPK Storage chamber

USV ABD switchover valve

Pressure curve of the "Rear right" brake circuit in the brake system with solenoid valves in rest position

 Solenoid valves de-energized, position "pressure passage free"

 The pressure goes unobstructed from the brake master cylinder to the wheel brake cylinder (HR) via the switchover valve (UVS1) and solenoid valve (EVHR) of the hydraulic unit (A1).

 The full brake pressure is applied to the wheel brake cylinder and solenoid valve (AVHR).

D42.30-0023-06

"Rear right" brake circuit with solenoid valve (EVHR) in switch position "passage blocked"

A1 Hydraulic unit

ASV ABD intake valve

AVHL ABS solenoid valve, pressure reducing, rear left

AVHR ABS solenoid valve, pressure reducing, rear right

AVVL ABS solenoid valve, pressure reducing, front left

AVVR ABS solenoid valve, pressure reducing, front right

D Damper chamber

EVHL ABS solenoid valve, pressure holding, rear left

EVHR ABS solenoid valve, pressure holding, rear right

EVVL ABS solenoid valve, pressure holding, front left

EVVR ABS solenoid valve, pressure holding, front right

RFP Return pump

RVR Non-return valve

SPK Storage chamber

USV ABD switchover valve

Pressure curve of the "Rear right" brake circuit in the brake system with solenoid valve (EVHR) in switch position "passage blocked"

 Solenoid valve (EVHR), position "pressure holding"

 The brake pressure from the brake master cylinder only reaches the solenoid valve (EVHR). The pressure in the wheel brake cylinder cannot increase.

 The pressure can escape via the non-return valve (RVR1) only after the brake is released, as equal or over pressure is applied at the non-return valve (RVR1) on the brake master cylinder side.

D42.30-0024-06

"Rear right" brake circuit with solenoid valve (AVHR) in switch position "pressure reducing"

A1 Hydraulic unit

ASV ABD intake valve

AVHL ABS solenoid valve, pressure reducing, rear left

AVHR ABS solenoid valve, pressure reducing, rear right

AVVL ABS solenoid valve, pressure reducing, front left

AVVR ABS solenoid valve, pressure reducing, front right

D Damper chamber

EVHL ABS solenoid valve, pressure holding, rear left

EVHR ABS solenoid valve, pressure holding, rear right

EVVL ABS solenoid valve, pressure holding, front left

EVVR ABS solenoid valve, pressure holding, front right

RFP Return pump

RVR Non-return valve

SPK Storage chamber

USV ABD switchover valve

Pressure curve of the "Rear right" brake circuit in the brake system with solenoid valve (AVHR) in switch position "pressure reducing"

 Solenoid valve (EVHR), position "pressure holding" and solenoid valve (AVHR) position "pressure reducing"

 The brake pressure from the brake master cylinder reaches the solenoid valve (EVHR).

 The solenoid valve (AVHR) is switched to passage. The brake pressure from the wheel brake cylinder reaches the storage chamber (SPK1) via the solenoid valve (AVHR) which temporarily receives the brake fluid which is flowing back.

 At the same time the pump motor M starts up and pumps the brake fluid out of the storage chamber (SPK1) back to the brake master cylinder via the non-return valve (RVR1), the damper chamber (D1) and the switchover valve (USV1).