Vacuum Pump Circuit and its Usage in automotive

[Rhyder88]

I have an vague idea that vacuum is used for effective braking system . Is there any online source available to understand about the circuit of automotive engine vacuum pump circuit and its uses .
Else could you elaborate about this circuit?

 

[140Airpower]

Pat, that's true. It's the reason that when boost is lost and the foot has to provide all the pedal force to get the required line pressure that this can be beyond the strength of the driver. A system designed for manual braking has to have more pedal stroke, lowering the needed foot strength. Similar with manual steering. A car like my Camaro would require at least double the turns lock-to-lock for reasonable manual steering force. I have driven manual steering cars and trucks and it's just a lot of hand-over-hand. But, I've never driven a non-boosted disk-braked street vehicle (under normal conditions).

 

[MikeHalloran]

There's another variable: master cylinder bore, which I think is typically a bit larger for disc brake systems than for drum brake systems.


Mike Halloran
Pembroke Pines, FL, USA

 

[patprimmer]

I have never driven anything I could not stop and steer even when belts threw or engine stalled at inopportune times. Sure it got hard, but an impending crash gives a pretty good adrenaline shot.

There are gears and hand (emergency) brakes that can assist.

I agree that it takes some good thinking to apply emergency brakes, but pressing harder and changing down are pretty much raw basic instinct responses that should instantly apply to just about anyone.

Regards
Pat
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[140Airpower]

Pat, I would have said the same thing if it were not for that singular experience. At that time, approaching the curve (at too high a speed for the pending emergency), expecting to do heavy braking, my hands and foot were already busy when the loss of power occurred. In retrospect shifting to drive 2 would have provided some engine braking and some vacuum, but the sudden heaviness of steering while setting up for the curve was not conducive to thinking about taking one hand off the wheel to do anything. The details of the situation dictate the choices and the amount of time to make and do them. Suddenly the car was virtually impossible to drive relative to speed and curve. It was adrenalin and body strength that saved me.
I continued down the mountain road to Pacific Coast Hwy at the bottom -coasting, but at a slow enough speed to be able to comfortably control the car, no problem, just as you would.

 

[Rhyder88]

thanks a lot for over whelming response. Now i have a clear idea