Why Power Brakes?

[vijay79]

Hello everybody. I want to understand the need of power brakes. We see power brakes in todays every vehicle (i might b wrong). Is it really necessary for light vehicles like cars to have this sytem? I agree that old cars like ambassadors and premier padmini with drum brakes were having little hard brake pedals but even then it is comfortable for braking. We need to apply a little more power while braking. But today we have powerfull disc brakes that doesnt need extra force to press brake pedal. Just a slight pressure on pedal or lever controls the speed amazingly. So what is the need for power brakes if we have to apply little force? Also power brakes system makes braking system depend on engine.if engine is off brakes also off. I think sometimes its risky.

 

[Akash1886]

We see power brakes in todays every vehicle (i might b wrong). Is it really necessary for light vehicles like cars to have this sytem? I agree that old cars like ambassadors and premier padmini with drum brakes were having little hard brake pedals but even then it is comfortable for braking.

Vijay, another unique one from you!

Power Brakes are a necessity in today's time because:

* Traffic has increased so driving and braking has to be accurate.

* Car's have light weight body shells as to increase fuel efficiency so to avoid a major happening power brakes are the right choice.

* Technical upgrades are a welcome change.

* Comparing it to Premier Padmini or Ambassador is wrong since at that time neither traffic was there nor technology was so advanced. The cars were relying on the structural strength only.

But today we have powerfull disc brakes that doesnt need extra force to press brake pedal. Just a slight pressure on pedal or lever controls the speed amazingly. So what is the need for power brakes if we have to apply little force?

At present in some high end cars like BMW et al there is a provision of electrical hand-brake where in you don't need to move your hand and pull the lever. Just press the button and its activated. But apart from that the cars in India at present are not so advanced that they can for go the ABC paddles. Though C Paddle is already not there in Automatics. Apart from that, Disc brakes are more accurate than drum ones.

Also power brakes system makes braking system depend on engine.if engine is off brakes also off. I think sometimes its risky.

Tell me the risk Vijay? If the engine is off then what's the problem? How will a switched off engine affect braking of the car?

Regards

Akash

 

[pravin1987]

air brakes are mostily found in heavy vechiles whereas the hydraulic system is found in passenger cars.

in hydrallic, Split brake system is the methods used now. A front and rear split system uses one master cylinder for pressurizin the front caliper pistons and the other section for pressurizin the rear.

diagonal split is a recent trend in this tye right front and left rear are served by one actuating piston while the left front and right rear are served by other. this is the safest braking type ven if both system fails, at least the front wheel braking will stop the vechile.

most of the modern cars are equipped with split or diagonal split types.


power brake is nothing but a brake booster .The brake booster uses vacuum from the engine to multiply the force that your foot applies to the master cylinder.

petrol engines produces vaccum( no chance of using this in a heavy vechile as most a diesel engines), since diesel engine does not produce vaccum a seperate vaccum pump is needed.

Air brakes are expensive and require a lot of mountin space becuase of compressors, Hydraulic systems are smaller and cost less

The switch to modern braking system( power/hydraullic)) is needed as the vechiles are faster. consider driving a audi with the brake system of a premier padimini.

 

[Releesh]

Tell me the risk Vijay? If the engine is off then what's the problem? How will a switched off engine affect braking of the car?

Regards

Akash

If engine switched off, brake boosters in your car dont work. you need to press hard to stop the vehicle then.Somtimes in slopes it may not be effective too.

 

[Mr.Boss]

Question is very simple as "Why do we need Power Steering?" We used normal steering in Amby & Fiats which were heavier than Alto / Wagon-R but still we have power steering in these lighter vehicles. Purpose of power assisted systems are to reduce the human fatigue.

power brakes system makes braking system depend on engine.if engine is off brakes also off. I think sometimes its risky.

Engine off + Vehicle Running/Moving == This isn't a condition a vehicle is designed for. I understand certain cases like parking in slope, etc but even in that case extra pedal effort could apply the brakes without any problem. I don't call it risky, but a little caution is required.

 

[vijay79]

If engine switched off, brake boosters in your car dont work. you need to press hard to stop the vehicle then.Somtimes in slopes it may not be effective too.

Yes its aboslutely true. Once engine is off, brake pedal goes down only two or three times and after that it becomes hard to press.

 

[stingray91]

simple reason.
to reduce stress of the driver!