The Student Room Group

Scroll to see replies

Reply 1
Don't drive in a way where you're constantly thinking of doing an emergency stop. Prevention is more effective than cure in this case.

The safest thing you can do is fit decent tyres to your car, these are the things which can stop you falling into ditches or into the back of other cars if used properly and work better than cheap ones. Pumping the brakes helps because it releases the wheels (re-establishes grip with the road) which either helps you turn to avoid what is ahead or when the brakes are re-applied it can help slow you down.

Youtube is very educational but this short of thing should really have been taught by your instructor.

http://www.youtube.com/watch?v=GKrgD_aSbg0

I'd follow the advice in the comments though and only pump in an emergency, you're still supposed to apply the maximum pressure you can without locking your wheels, if they do lock up you need to release and re-apply.
Reply 2
The best thing to do is to find an empty industrial estate and practice braking hard around there. You will eventually be able to sense when the wheels are going to lock and will learn to reduce braking pressure before this lockup point. The theory behind it is simple enough, but there's no substitute for practicing it in a safe environment. You don't want to be trying to establish the lock up point for the first time in an emergency situation.
Reply 3
as has been touched upon above, the basic principle is controlling the amount of brake pressure applied so that you can apply the maximum without stepping over the very fine line and locking the wheels up. once the wheels are locked up, they will travel in one direction only. you really need to experience this in a controlled environment before getting used to it.

alot of people will tell you that as soon as they lock up, or just about to, release the pedal. thats fine in principle, but those people clearly havent practiced this sufficiently.

modern cars have power assisted brakes, so the point between maximum and lock up is very hard to fine. and once you have locked up, lifting off the pedal entirely will mean the car will plough on for quite a distance and probably straight through whatever it is your trying to avoid!

so do not get into the mind set that your going to pump the pedal because that makes you travel so much further. when you do lock up, dont lift off entirely, 1/2 pressure in my experience is enough to start them spinning again.

study this! - http://www.youtube.com/watch?v=r3L4Pi5PmV4&feature=related
Reply 4
If I was a passenger in a car which was about to crash, and the driver began pumping the brakes, I would be forced to intervene.
Mid-crash, I'd be like "Wait just one ******* minute! What the **** are you doing?!" I'd not move an inch until I got a full explanation, and I'd then step out of the car, give the driver a sincere look of disgust, and walk away, leaving him to crash.

But in all seriousness, are there actually people out there who believe you should manually pump the brake? My fears for my own safety on the road have just increased tenfold.
Reply 5
Ghost
If I was a passenger in a car which was about to crash, and the driver began pumping the brakes, I would be forced to intervene.
Mid-crash, I'd be like "Wait just one ******* minute! What the **** are you doing?!" I'd not move an inch until I got a full explanation, and I'd then step out of the car, give the driver a sincere look of disgust, and walk away, leaving him to crash.

But in all seriousness, are there actually people out there who believe you should manually pump the brake? My fears for my own safety on the road have just increased tenfold.


Pumping is the wrong term for it, though if you slightly increase and decrease pressure on constantly over the lockup point for the brakes you seem to get the best possible stopping distance (on non power assisted un monitored for ABS braking systems).

Its something that most people will never have to do, and will never drive a car on which its a good idea.

In the case of a hydraulics failure on the big old BXs they had reinforced discs on the front so pumping the hand-brake (again not all the way up all the way down etc) would stop them (and having seen it done pretty damned quickly too).

The only system I have ever had to pump up was on an old landrover, you needed two strokes of the pedal before you got any braking from them.
Reply 6
Yes, find some space to practice. Pumping the brakes is only useful in very specific circumstances, in most cases it has much more to do with getting a feel for the brakes to avoid a lock-up. I had a friend of mine who races Formula Ford and works for Palmer Sports teach me non-ABS braking techniques. Good fun!
Reply 7
terpineol

In the case of a hydraulics failure on the big old BXs they had reinforced discs on the front so pumping the hand-brake (again not all the way up all the way down etc) would stop them (and having seen it done pretty damned quickly too).


i knew they it did the front brakes but i never knew you could do that! :smile:
Ghost
If I was a passenger in a car which was about to crash, and the driver began pumping the brakes, I would be forced to intervene.
Mid-crash, I'd be like "Wait just one ******* minute! What the **** are you doing?!" I'd not move an inch until I got a full explanation, and I'd then step out of the car, give the driver a sincere look of disgust, and walk away, leaving him to crash.

But in all seriousness, are there actually people out there who believe you should manually pump the brake? My fears for my own safety on the road have just increased tenfold.


Is this a joke? Would you rather they locked the wheels and lost all control of the car? Yes, ideally you would threshold brake, but to be perfectly honest the chances of achieving this in an emergency situation are little to none for most drivers - Cadence braking is a suitable middle ground which allows you to brake and avoid.
Clearly if you're on dry tarmac you'll probably stop faster by locking the wheels, but I'd imagine there are very few situations where having no control of steering isn't an issue.
Reply 9
Elementric

Clearly if you're on dry tarmac you'll probably stop faster by locking the wheels, but I'd imagine there are very few situations where having no control of steering isn't an issue.


tarmac is just before lockup, gravel and other loose serface is better to drag wheels. but still, if you drag the tyres have no ability to turn.
Reply 10
Elementric
Is this a joke? Would you rather they locked the wheels and lost all control of the car?


Completely serious. I've been in situations which have involved needing to emergency break - people pulling out in front of me, fallen trees over the crest of a hill on a country road, etc. It isn't that difficult to not lock up the wheels, and as someone else said in this thread it's worthwhile practicing in an empty carpark in order to get a feel for the braking threshold.

I'm not claiming to be a superb driver or anything; I'm average at best. I just think an inexperienced driver pumping the brakes needlessly would add extra danger to an already dangerous situation. There's a reason people aren't taught to do it on the driving test.
Reply 11
I drive a 20 year old Land Rover with no ABS. The rear wheels lock up way before the front, which gives me a nice indicator for how hard to brake, as I still get steering (albeit with a bit of slide in there too). The brakes are surprisingly good for such an old and primitive car, much more modulation and feel than those in my parent's 2 year old Astra.
Lara C.
i knew they it did the front brakes but i never knew you could do that! :smile:


Citroen are pretty keen on front disc acting handbrakes.

When my carb was last playing up it was very useful, I was only using the handbrake for a while.
Ghost
Completely serious. I've been in situations which have involved needing to emergency break - people pulling out in front of me, fallen trees over the crest of a hill on a country road, etc. It isn't that difficult to not lock up the wheels, and as someone else said in this thread it's worthwhile practicing in an empty carpark in order to get a feel for the braking threshold.

I'm not claiming to be a superb driver or anything; I'm average at best. I just think an inexperienced driver pumping the brakes needlessly would add extra danger to an already dangerous situation. There's a reason people aren't taught to do it on the driving test.


Actually my instructor was keen to say its not taught because if you do it with ABS the system doesn't have a clue what is going on and you won't stop for miles, but if you were to do the test in your own car without ABS he would teach it.

I did the test in his car with ABS, but we went out in mine later to brush on on cadence braking.
Reply 14
Ghost
I just think an inexperienced driver pumping the brakes needlessly would add extra danger to an already dangerous situation. There's a reason people aren't taught to do it on the driving test.


I learnt in cars with ABS, without ABS and one that apparently had ABS but still locked the wheels when doing an emergency stop, and I was taught cadence braking. My instructor said that if you lock the wheels during an emergency stop on a driving test then you get a serious driving fault/major for the emergency stop since you "weren't in proper control of the vehicle". However I imagine if you were pumping the brake pedal to such an extent where you were going from pretty much full-on to full-off brakes then you'd also get a major for that :p:

Of course what you should do, rather than just blindly pump the brake pedal is start to feel when the wheels lock up (I found this surprisingly easy to notice, even when it caught me off-guard in the car which supposedly had ABS but obviously didn't) and release the brake pressure until they unlock and start rotating again, and then reapply the pressure up to a point just before where the wheels will lock. Such a thing comes with practice and I am by no means perfect at it!
Reply 15
I don't have ABS and have had to emergency stop a few times, not once have I locked up. You'll get a feel for your car after a while and know exactly at what point they'll lock up.
Reply 16
may as well use the hand break to turn :biggrin:
Reply 17
How is it that people still haven't learnt the difference between brake and break? Maybe I should have known from the lack of general punctuation and the awful rep.
Ghost
. I just think an inexperienced driver pumping the brakes needlessly would add extra danger to an already dangerous situation. There's a reason people aren't taught to do it on the driving test.


who told you that ...

or perhaps the ex RCT WO1 that taught me to drive or the Ex RPU sergeant that taught my brother to drive are both muppets ?

or perhaps the serving RPU officers that took the skid pan session at the police driving school are muppets ? ( that is fun a 2.9 granada with bald tyres and a an on/off switch for the ABS )
EGjeff
I don't have ABS and have had to emergency stop a few times, not once have I locked up. You'll get a feel for your car after a while and know exactly at what point they'll lock up.


you are not braking hard enough if you don't reach at least the threshold of lock ...

Latest