Vacuum Pump Circuit and its Usage in automotive
Vacuum Pump Circuit and its Usage in automotive
(OP)
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?
Else could you elaborate about this circuit?





RE: Vacuum Pump Circuit and its Usage in automotive
Regards
Pat
See FAQ731-376: Eng-Tips.com Forum Policies for tips on use of eng-tips by professional engineers &
http://eng-tips.com/market.cfm
for site rules
RE: Vacuum Pump Circuit and its Usage in automotive
RE: Vacuum Pump Circuit and its Usage in automotive
Do you imagine a situation where you would not close the throttle as well as applying the brakes?
Are you a high school student?
Are you ant sort of engineer?
Regards
Pat
See FAQ731-376: Eng-Tips.com Forum Policies for tips on use of eng-tips by professional engineers &
http://eng-tips.com/market.cfm
for site rules
RE: Vacuum Pump Circuit and its Usage in automotive
Benta.
RE: Vacuum Pump Circuit and its Usage in automotive
- Steve
RE: Vacuum Pump Circuit and its Usage in automotive
RE: Vacuum Pump Circuit and its Usage in automotive
http://i.ebayimg.com/t/G4-87-VOLVO-240-VACUUM-RESE...
RE: Vacuum Pump Circuit and its Usage in automotive
The BMW ValveTronic uses the inlet valves as throttles. Closed inlet valves on the inlet stroke do the same thing as a closed throttle plate.
Regards
Pat
See FAQ731-376: Eng-Tips.com Forum Policies for tips on use of eng-tips by professional engineers &
http://eng-tips.com/market.cfm
for site rules
RE: Vacuum Pump Circuit and its Usage in automotive
"...what will happen if there is no vacuum pump in the engine..." ?
The answer to this is No Brakes. If the engine quits or the THROTTLE STICKS OPEN, brake vacuum is lost and the driver will have a hell of a time trying to stop the car. Engine quitting happened to me on a mountain road (hole in gas tank) and I almost flew over a cliff "to heaven". A runaway throttle is similar. Poor braking against a pulling engine may cause the driver to pump the brakes, dumping the stored vacuum and having no ability whatsoever to brake the car.
Usually, the engine-as-vacuum-pump is a reliable built-in source for vacuum-powered brakes. Normally, under braking the engine is idling or motoring at closed throttle, pulling a high vacuum and continuously replenishing the vacuum canister. Fine system. I would prefer an auxiliary vacuum pump (wouldn't have solved my mountain road problem) or electric power brakes (not available).
RE: Vacuum Pump Circuit and its Usage in automotive
Up until about 50 years ago, very few cars had power assistance to the brakes and they still stopped.
Regards
Pat
See FAQ731-376: Eng-Tips.com Forum Policies for tips on use of eng-tips by professional engineers &
http://eng-tips.com/market.cfm
for site rules
RE: Vacuum Pump Circuit and its Usage in automotive
TTFN
FAQ731-376: Eng-Tips.com Forum Policies
RE: Vacuum Pump Circuit and its Usage in automotive
Disk brakes don;t.
When I was younger and stronger I had a non power brake Ford F150 pickup, with front disks (and a factory 8 track player). I often used both feet for normal stopping.
RE: Vacuum Pump Circuit and its Usage in automotive
Of course, that car weighed half a ton less than most of today's cars and a ton less than some.
Norm
RE: Vacuum Pump Circuit and its Usage in automotive
----------------------------------------
The Help for this program was created in Windows Help format, which depends on a feature that isn't included in this version of Windows.
RE: Vacuum Pump Circuit and its Usage in automotive
Terry
KI6FCI
RE: Vacuum Pump Circuit and its Usage in automotive
I don't call that driving.
In the scenario I described I didn't mention that I also lost power steering on a Camaro w 2.7 turns lock-to-lock. It was downhill. It took ALL my strength to slow the car enough and to turn the wheel enough to stay alive. That was many years ago. Today I wouldn't make it, nor would any woman, nor an elderly person.
In general, sudden loss of brake boost is potentially fatal. Same for a runaway throttle, especially for a person with no expectation and experience. The fail-safe condition for safety systems is that they should work under loss of power. The power brakes on that Camaro did not work if I, a strong man, was standing on the pedal and could not lock the wheels.
HowDidYouBreakThat, I'm curious about your Ford truck. I was not aware of any disk brake system on a heavy vehicle that did not have boost. As mentioned, drum brakes have self-servoing action, but disks do not. Did the pedal have more travel than normal?
RE: Vacuum Pump Circuit and its Usage in automotive
How about this for fun: I was driving a Freightliner w/53' trailer across Montana when my transmission exploded. The input shaft was locked, but the truck would roll. Tow truck pulled me about two miles with chains to the top of the hill so I could drop the trailer. One foot on the clutch, one foot on the brake with the engine idling. My left leg almost didn't make it to the top.
Terry
KI6FCI
RE: Vacuum Pump Circuit and its Usage in automotive
RE: Vacuum Pump Circuit and its Usage in automotive
Regards
Pat
See FAQ731-376: Eng-Tips.com Forum Policies for tips on use of eng-tips by professional engineers &
http://eng-tips.com/market.cfm
for site rules
RE: Vacuum Pump Circuit and its Usage in automotive
RE: Vacuum Pump Circuit and its Usage in automotive
Mike Halloran
Pembroke Pines, FL, USA
RE: Vacuum Pump Circuit and its Usage in automotive
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
See FAQ731-376: Eng-Tips.com Forum Policies for tips on use of eng-tips by professional engineers &
http://eng-tips.com/market.cfm
for site rules
RE: Vacuum Pump Circuit and its Usage in automotive
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.
RE: Vacuum Pump Circuit and its Usage in automotive