Car question: How to stop a brakeless car?

[SpyderEdgeForever]

I was watching one of these action/mystery movies and in one scene the bad guy cut the brake lines in one of the character's cars, and caused them to lose control and wreck. My question is this: In real life, if someone were in a car that for some reason or another lost the brakes, what are some good survival methods to keep in mind, to stop the car safely or reasonably safely enough to live and not be too damaged?

Also, how would the type of car effect the stopping of it when the brakes are gone? would an older model that is more mechanical as opposed to new cars with more electronics probably be easier to stop because you have more manual control options?

[bdblue]

Cars these days have dual braking circuits, you would have to cut more than one line to disable the brakes. Cars have been this way for a long time.

Some if not all cars, old or new, have mechanical emergency brakes that could be engaged. Domestic cars usually have a foot pedal, a lot of foreign cars have a handbrake.

If you have a manual transmission all you have to do is to turn off the engine and engine pumping losses will slow the car down. Some pickups and SUVs have the ability to use engine braking through the transmission but not all of them. For that matter some cars with pushbutton start may be resistant to turning off the engine if the car is moving.

As a last resort you have to look for obstacles to slow down the car- hills, etc.

[Evil D]

Well if you drive a stick, start aggressively down shifting until you're in first, then ease on the e-brake. If you're in an automatic you can try to do the same if the type of shifter it has will allow you to drop down gears. Worst case scenario is find a ditch that isn't too crazy and drive into it.

I'd avoid shutting the car off...most cars still use hydraulic power steering...if you shut the car off, you also shut off the power steering.

[Knivesinedc]

If someone managed to cut your main brake lines, your Emergency brakes would still work. Downshifting aggressively, like D said in a Manual then applying the E brake should work fine. In an auto, most cars have gears "1" and "2" on the shifter. Move the shifter into 1 and that will slow you down significantly, then, apply the E brake.

[3rdGenRigger]

In the movie world something like a car with no brakes on the highway might make sense. In reality however, you use your brakes to stop your car after reversing out of your parking spot, and if someone cut your brake lines you'd just reverse into something and immediately know something was wrong before you even made it out of the parking lot/parking garage/wherever you park your car. You'd almost certainly never make it to a highway or to anywhere that you'd be at enough speed to cause any serious harm.

Now, losing your brakes for reasons beyond tampering will almost certainly be more of a problem. On large trucks with air brakes if you lose air pressure your brakes will "Dynamite" which means they'll lock up completely, but the drums can also glaze over if they get too hot, and they may not be able to stop the truck on a steep grade even with full brake pressure. This is only typically an issue on very steep grades like mountain passes and there are typically "Runaway" lanes that are filled with very loose and deep gravel that will scrub speed off an uncontrolled vehicle very quickly in order to stop them safely if they lose control of their braking ability. I drive a large truck, not usually in the mountains, but every few months and I'm always aware of what I'd need to do if I lost brakes.

Your initial question is a little vague...the movie scenario is completely manufactured for television and not realistic in any way. Real life scenarios are a little more situation specific. I've been in situations where I've been sliding towards the vehicle in front of me (On black ice) and turned into the curb to be able to stop. Worked fine and prevented an accident. If I was on a country road (I live in the country so I'm always prepared for this), I'd hit the ditch and take out someone's fence before hitting a stopped car because I can fix a fence easily...paying someone to fix someone's car and the added insurance costs would hurt me a lot more, not to mention the possible injury to anyone in a car that I might hit. I'd much rather hit a fence.

[Evil D]

I have lost brakes before while driving. I had an '88 Bronco II that had rusted out brake lines and one had blown and I lost all brake fluid. I was on an exit coming off a highway and that exist ended in a red light and you had to turn left or right. Fortunately there was nobody already stopped at that light but it was red and I ran it like a chase scene from CHIPS, blowing my horn the whole way through. It was a 5 speed manual so I got it stopped by down shifting and the ebrake and managed to limp it all the way home that way.

[demoncase]

I find hitting a brick wall does the job fairly effectively :D

[bdblue]

I bought a new car in 1990 (the last new car I've bought). The first week I owned it I left my house on the way to work. Approaching a traffic light a low speed on a lightly traveled street, the brake pedal went to the floor and I had very little braking. I was able to slow down enough. Instead of turning one way to work I turned the other way and went to the dealer. I told the service manager that there was a problem with the braked, he wrote it on a piece of paper and put it on the car windshield. I told him that he didn't understand, there was almost no brakes. One of the kids working there would get in the car to drive it around the back and end up driving through the side of their building. That got his attention and he wrote a warning note to put on the car. This was a new car model and parts weren't available, they ended up taking parts off of another car they had in stock in order to fix mine.

[bearfacedkiller]

All good advice above.

Start pumping them like crazy. I have had my brakes go out from a rusty line and vigorous pumping got me to a stop. If that don't work then...

Downshift.
E-brake.
Pull onto soft ground.
Turn up hill.
Put it in the ditch.

New brakes are just as mechanical as old brakes. There is ABS but in the end they are mechanical and not electric. We have gone to drive by wire throttles but thankfully nobody has gone to drive by wire brakes. At least not that I am aware of. Even if we go down that road a mechanical e-brake will presumably always be required.

[Pinetreebbs]

We have a particularly steep driveway, it drops more than 100 feet in elevation and is difficult to walk up or down because of the steep angle. Guests have asked what I'd do if I lost my brakes, I always, say, "I'd steer off the driveway and hit a tree right away." Why? "Because at the bottom I'd be hitting another tree or my house much harder."

In most vehicles today it's a parking brake that at best operates one shoe in rear drums or is a miniature drum in addition to disk brakes. The point is, they have very little braking power. The quicker you take action, the better off you'll be, the longer you wait, the faster you'll be going, the harder it is to stop and the harder you will hit.

[Doc Dan]

I just had the ABS go out in my wife's car while I was driving it. The brakes pedal went to the floor and I had no brakes at all. So, I down shifted the auto transmission into the lowest gear while gently applying the mechanical parking brake.
I have had to do this with tractors on the farm, too. Now that is exciting, especially when mowing a hillside, believe me!

[SpyderEdgeForever]

Is there some "extra mechanical safety device" that can somehow be engineered into car designs, that is independent of the brakes and emergency brakes, something akin to the "Otis Safety Brake" used on elevator systems:

http://www.otis.com/site/us/pages/OtisH ... x?menuID=6

Something that could be instantly activated either manually or automatically, independent of all brake lines and brake fluid, and would literally lock the wheels from turning at all.

[Doc Dan]

Perhaps but I see all sorts of dangers in such a system. I knew a guy that used to get in your car going somewhere and reach over and pull hard on the handbrake! Idiot.
Also, remember the current airbag fiasco.

[remnar]

If someone managed to cut your main brake lines, your Emergency brakes would still work. Downshifting aggressively, like D said in a Manual then applying the E brake should work fine.

I've had to do exactly that in an old manual transmission Fiat when the seals in the master cylinder suddenly blew out. I was driving in very rainy conditions and rounded a corner to find water over the road. When I applied the brakes the pedal went all the way to the floor with no pressure at all. After hydroplaning off the road and then being pulled out of the ditch by a good samaritan, I drove the car about ten miles to a shop to have them look at it. Down shifting and using the e-brake worked ok to get me to the shop but it wasn't good for the nerves.

[bearfacedkiller]

Is there some "extra mechanical safety device" that can somehow be engineered into car designs, that is independent of the brakes and emergency brakes, something akin to the "Otis Safety Brake" used on elevator systems:

http://www.otis.com/site/us/pages/OtisH ... x?menuID=6

Something that could be instantly activated either manually or automatically, independent of all brake lines and brake fluid, and would literally lock the wheels from turning at all.

Commercial vehicles will lock up automatically if your air pressure gets too low. Not fun.

[Echo63]

I have actually had the brakes fail, in my parents car while i had my probationary drivers licence (long story, but disks shouldn't be machined thinner than recommended, as the pads can fall out when they wear down enough)

taking off from being stopped waiting to turn, i heard what sounded like a glass bottle rolling under the car - it wasn't, instead was the brake pads sliding inside the rim, on the way to being left on the road
luckily i noticed, when the brake pedal went straight to the floor, before i needed to stop in a hurry, or slow rapidly for a turn
being a manual (stick) diesel 4x4 it had great engine braking, so i slowed using the gearbox (including a double clutch into second for the stuffed synchromesh and then back to first) and turned off into a fuel station and stopped the car with the handbrake.
walked the 5km home, then dropped dad off in his car 6 hours later at midnight, and he carefully drove it very slowly.

luckily it was a diesel, which engine braked beautifully, and the handbrake was a massive drum unit, on the back of the gearbox - no good for a handbrake turn, but excellent as an emergency brake when applied gently
My personal cars are all manual transmission, and i would do a similar thing if it happened again.
hopefully i never need too (once was enough)

[Monocrom]

One note about applying emergency brakes.... You want to push down on that left-most pedal slowly, or pull up on the handle slowly as well. Especially if you're going at a very high rate of speed.

In the Winter, you can try to steer at an angle towards a snow bank. Not adviseable at a high rate of speed though. That advice, by the way, comes from first-hand experience. And no, I'm not going to go into detail about the circumstances. Expect your car to rotate around when you hit the bank.

[farnorthdan]

there's always the Fred and Barney method :D for some reason this image pops into my head when I read this thread title



Sorry guys, I grew up watching the Flintstones and just couldn't help myself :p

[JAfromMN]

Jump out of the vehicles and try roll with it.

Lol