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Should emergency brake stop car?

I seem to remember way back in driver's ed that if you lost your brakes, you could use the emergency brake to stop the car. Obviously this would only work in certain situations where the handbrake bypasses the problem with the floor brake (i.e., loss of brake fluid).



I have a 97 Corolla, and decided to give this a try. I was going about 25 mph on a flat, straight road. I put the car in neutral, let it coast, and pulled up on the emergency brake. I could feel the braking, but barely! In fact, once I hit a slight downhill, the car picked up speed again. Obviously, this isn't going to save me when I'm going down a mountain and my master cylinder gives out!



The questions - am I right that the hand brake should be able to stop the car? If it can't slow me down, is it doing anything when I use it for other purposes (say, when I'm parked on a hill?)
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Comments

  • edited December 2008
    Check your owner's manual. I believe the brake you are talking about is referred to as the "parking brake," and its primary purpose is to hold the car in place when it's parked.

    The term "emergency brake" went out of fashion when dual-diagonal braking systems came into being, which was a LONG time ago, and the parking brake is not designed to stop the car.

    If you pulled hard enough (not easy to do) you could, eventually, stop the car with the parking brake, but it would not be easy, and I don't recommend it.

    It's highly unlikely that you would lose all brake fluid at once. The primary braking system would still do a better job of stopping the car, even with low fluid, than the parking brake will ever do.

    Use it when parking, but don't expect it to stop the car in an emergency situation.
  • edited December 2008
    It's called a parking brake rather than an emergency brake because it is not designed to stop the car, only hold it in place once it's at rest. As a matter of fact, most modern cars with rear disc brakes use a tiny drum cast into the center of the disc and tiny shoes for their parking brakes. It does not have sufficient power to stop the car in any meaningful distance by itself.

    Having said that, should I ever lose my hydraulics entirely I'M PULLING THE HANDLE! My parking brake WILL be used as an emergency brake even if it fries trying!
  • edited December 2008
    Also, I don't know what kind of brake setup this car has, but on many cars with rear wheel disc brakes, the parking brake is like a little miniature drum brake within the rear disc and the shoes on it are very very thin because they're not actually designed to ever stop the vehicle-- just hold it in place. So if you do one or two of your little tests, you'll have a worn out parking brake!
  • edited December 2008
    Having said that, should I ever lose my hydraulics entirely I'M PULLING THE HANDLE! My parking brake WILL be used as an emergency brake even if it fries trying!



    Me too, and I had to do it once when a brake line bust (rusted) and the dual brake cylinder divider also broke. It stopped but I was almost all the way through a busy intersection by then. It was luck and good driving by several other drivers that saved me from an accident.
  • edited December 2008
    Not only is this a parking brake, but it only activates the rear brakes. The front brakes do most of the stopping (about 70%) in normal use. So don't expect it to work as well as all four brakes together.

    I would pull the parking brake in an emergency where the normal brakes fail, but since they only work on the rear axle, stopping distance would be signifigantly increased. In a true emergency, you should also downshift, even if you are driving an automatic.

    Keeping your car stationary is far easier than stopping it. Don't judge the effectiveness of your parking brake in this manner. Besides, when parked on a hill, the transmission should provide extra insurance, since it will either be in park (automatic) or in gear (manual), right?
  • edited December 2008
    I disagree to some extent with your responses so far. Yes, the emergency/parking/hand brake is supposed to be able to stop a car. It won't do it nearly as quickly as the main brakes, but it is not just a "parking" brake. By law it still serves the as an "emergency" brake in the case of total failure of the main brakes. Yours is either broken, mis-adjusted, or the rear pads are worn out. The parking/emergency brakes on both of my cars work well enough to stop the car, yours should too.
    Some parking/emergency brakes work as the other posts have described, using small drums at the back wheels. Others work by squeezing the rear calipers and therefore use the main (and only in this case) rear brake pads. Even when the main brakes are working correctly, the rear wheels do very little of the braking effort, so that is another reason that the parking/emergency brake is pretty weak. Still, as long as your foot is off the gas, it should be able to stop the car. Get yours fixed.
  • edited December 2008
    I should add that if you don't always use your parking brake when parked, that might be why it is out of adjustment.
  • edited December 2008
    Just a little anecdote: I remember when I did my driving test the guy asked me for the location of the "emergency brake". I had never heard that term before and had to think for 2 seconds and pointed to the parking brake. Turns out my guess was right.

    That being said: The parking brake slows down the vehicle a bit but not much. In your experiment you should have shifted down substantially to 1st gear and THEN applied the parking brake. In that case it should have enough power to stop you.


  • edited December 2008
    Tardis is correct. Your brake is not working properly and needs to be fixed.

    Every car I have ever owned has been able to completely lock the rear tires by applying the parking/emergency brake. This is how it ought to be. If you pull the handle all the way up, the tires should be totally unable to turn. Period. They should skid on the pavement before turning. When you performed your test and pulled the parking brake at 25MPH on a flat road, there should have been people running out of their houses to see the squealing tires and burned rubber.

    Granted, you need to really man-handle that thing to get the wheels to lock. But if you reach the end of the handle's range of motion and those rear wheels are still turning, that is a problem and should be fixed.

    There's clearly a widespread myth out there that this brake is somehow only supposed to be used when the car is already parked. Yes, you'd normally never ever use this brake to actually stop the car, and yes, you primarily use it to hold the car in position while it is parked. But think about it, if it *doesn't* bring the car to a stop while it is moving, then how can it possibly have enough holding power to keep the car from rolling down a hill? Simple answer: It doesn't!

    Lots of peoples' parking/emergency brake is in poor repair because of several factors: 1) Steel cables are used to operate the parking brake, instead of hydraulic lines. Steel will stretch and rust over time, giving you less effective braking power. 2) Rear drums have an auto-adjuster which is supposed to keep the pads near the drum surface. But this auto-adjuster can freeze and no longer extend the pad to make up for wear. 3) Automatic transmissions with a prawl on the output shaft have made many think that the parking brake is redundant. (which is true to some extent, but does not eliminate the need)

    So, yeah - take your car into a shop and have them tighten up the cable. As long as other stuff is in good repair this should be a simple fix.
  • edited December 2008
    This is what's interesting about a board like this with different posters and different opinions. I would not take any particular post as gospel, but read all of them and come to your own conclusion. I'd had cars where the park/emergency brake would lock up the rear wheels and cars where the properly adjusted and maintained park/emergency brake would not lock the rear wheels. One thing for sure is that you should at least feel the brake try to slow the vehicle down somewhat. If it doesn't, then perhaps the brakes or cable needs adjusting/replacing. You can talk to 3 guys who have over 30 years of wrench turning each and I promise you'll get three different answers, so experience is not always a good indicator for a question like this. When a manufacturer comes out in the owners manual that says the park/emergency brake is supposed to lock up the rear wheels when applied at 30 mph, then, and only then will I change my opinion. But we both know that ain't happening.
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