How does a brake servo work?

Answer 1

If the vehicle is equipped with an Otto engine with a throttle plate, the negative pressure in the intake pipe is usually sufficient to operate the brake servo unit. All other engine types, including the Diesel engine, have to have a vacuum pump. In both cases, while the engine is running, the negative pressure is directed through a one way valve into both chambers of the brake servo unit. As long as the brake is not operated both chambers are connected with each other via channels. There is a movable diaphragm in between the chambers.

If the driver starts braking, the connecting rod moves left, pressing the seal of the double valve against the valve seat, thereby closing the connection between the two chambers. In accordance with the brake pedal force, more or less air at atmospheric pressure gets into the right chamber via an air cleaner (see arrows!), intensifying the brake force. The pressure in the right working chamber is bigger than in the left vacuum chamber. The diameter of the servo unit, still indicated in inches, determines the maximum braking force. For heavier vehicles one might make use of three or four chambers if there is not enough space for one sufficiently large unit. If there is a hydraulic system already present, the support work might be taken over by a substantially smaller hydraulic servo brake.

ANS2:

• A valve that is actuated when the brake pedal is depressed reduces atmospheric pressure on the master cylinder side of the servo diaphragm. The higher atmospheric pressure on the other side assists the brake actuator push rod to apply force to the piston in the master cylinder. This is the most common arrangement in modern vehicles. In gasoline-powered vehicles the engine manifold vacuum is used to provide the pressure differential.

• The brake system found in diesel-powered vehicles typically uses a vacuum pump to provide the vacuum since manifold pressure in a diesel is the same as atmospheric.

• Trucks with air brakes use compressed air to push air servos (commonly called 'pancakes') located at each wheel. When air pressure is removed, a spring pulls the brake tight. A truck with air brakes will not roll until it builds up air pressure.
• Drum brakes have a servo action that results from the 'wrapping' effect of (usually) the leading shoe. That explains why the leading shoe generally has more lining than the trailing shoe. As the leading shoe engages on the surface of the drum, its geometry causes it to set tighter and transmit some force to the trailing shoe. Cars with drum brakes generally have noticeably less braking performance when stopping in reverse.
• Band brakes, similarly, benefit from the wrapping servo effect and also work poorly in reverse but you typically don't find band brakes on anything larger than a riding lawnmower.

Answer 2

It is a sexual position where you are with 17 men and insert a probe into each others anus. Best of luck

Alan

Answer 3

The purpose of the brake servo is to help the brakes stop the car in the braking process.