warninng Disc brakes!

someone said the handbrake is dangerous and lets the bite go when cool'd down
http://www.thesun.co.uk/sol/homepage/news/3982392/I-saw-my-car-crush-son-5.html
cant believe manufacturers know and sold this.

Bulls*** If you do 30 laps of Silverstone in an F40 then park on a 1 in 3 incline and leave it overnight, then perhaps, maybe it could roll back. The woman just didn't put it on.

Terrible sadness that this happened, but I have to agree with Josh, I don't believe this could happen in the manner described - how much can a car's brakes cool down and unstick in the short time between getting out of the car and what sounds like seconds later?

It serves as a valuable warning about the importance parking in gear (which I was taught in lessons, it's mentioned in the highway code, and in the Micra owner's manual - some people need to think more carefully about what they're doing with a one ton machine).

Handbrakes fail more easily than some people realise. My Brabus passed it's MOT, drove it home the long way (40 odd miles ) using the handbrake at lights etc, as I do. I got home, pulled the handbrake, and it pulled all the way up to the top and JUST held the car! The worst thing is, you have to take the rear wheels off to adjust it!

load of crap.

a handbrake caliper is pulled on with a force as great as you stamping on the foot brake... in order for the disc to have cooled down enough for the size to have changed significantly enough for it to slip.... it would have had to be glowing red hot before it was applied AND not have been applied correctly.

Handbrake not on properly i reckon, plenty of cars use the same handbrake system without problems.

My first k11 with rear discs used to have poor handbrake grip cos one caliper had seized up and other pne was close to seizing so only had partial braking. Replacing or overhauling the caliper mechanism restored full braking capability.
So a neglected system could affect the calipers grip performance for a given pull force on the handbrake.

When handbrake is applied, theres usually some elastic stretch on the cable mechanism so there's a degree of give between having enough tension to hold the car static and not enough tension that it begins slip.

Another factor is static friction vs dynamic friction of the rear pads. Static friction is usually higher than dynamic friction. If u only apply just enough handbrake to barely hold the car static, the slightest nudge such as wind or football or other external additional loading may overcome the pads static holding ability and end up relying on its lower dynamic friction ability once it slips.
Now in the case of parking on a incline, the dynamic friction may not be able to brake the car falling under gravity and once it gets going it just gets worse n faster.

Another factor is weight. I woulda thought during parking the driver would apply enough handbrake to hold the car still before exiting. Once they exited, the car will be lighter by the weight of the driver and any passenger/cargo but the handbrake is still set to withstand the original heaviest weight.

This means that the additional force i mentioned before in order to overcome the static friction into dynamic friction would have to be equal or greater than the weight of the driver and any passenger/cargo during parking.

Unless in an unlikely and crazy situation that the driver had instantly exited the car and applied barely enough handbrake to hold Just the cars weight the instant the car had stopped on the slope.

good good
i got mine start working on the first click

this is rubbish... its either the dipsy woman forgot to put it on or one of then electronically operated pieces of rubbish

done a winter emergency brake check yet ?

ooooeerr gulp
http://www.mirror.co.uk/news/top-st...ndbrake-jailed-for-two-years-115875-23685491/

good habit keeping hand on the handbrake

The story was in the Sun, do you expect all the facts or the whole story?.

I wonder what really happened and think I can guess but we'll never know for certain.

Roger.

yeh yeh i want it all the facts figures and hoo pulled the trigger
the womans traumatized rest of her life,shook up taken to book up

i am seeing a connection here, women and cars....

Agreed, it was the Defence Council's explanation as to the cause of the tragic accident, not an independent expert.
Unfortunately if the handbrake was applied until the sound of the first click, then it might have appeared to be on, however with the movement
of an adult and two children exiting the vehicle, this could have set the vehicle in motion down the slope.

Very sad occurrence, rubbish explanation .....