Please could someone advise me on whether I have a problem or not. I parked my new (February 2007) mini cooper on my rather steep drive earlier this afternoon and went indoors with the shopping. Ten minutes later there was a very loud bang followed by a car alarm. Needless to say it was mine; the car had aimed itself squarely at the garage and has bent the door (up and over variety) back so that I would imagine a new door will be required. Fortunately, the damage to the car is minimal and amounts to a couple of tiny specs out of the paintwork on the bumper. I suppose the distance travelled was only about 5 feet but the force exerted was evidently considerable owing to the gradient. My question is this. The handbrake was on (most definitely, checked when I got in the car to reverse it back up the drive) but I had not put the car in gear. It is possible that the brake was not pulled right up to the limit as I have always understood this is bad for it but it was certainly almost there. Should I go back to mini or is this due to the fact that I did not put the car in gear. Having been used to an automatic I did not really know that this was essential when parking on an incline. In other words is this my own stupid fault or could there be something wrong with the car? Of course, there is also the matter of insurance - would household buildings/contents cover the garage door and would there be a query over the safety of the car?
Any advice gratefully received.
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I don't know how the Mini handbrake works, but the same sort of thing happened to a friend's Dad back in the Seventies with his brand new Audi 80. In his case the damage to car was very serious.
The handbrake worked on the rear discs rather than on a separate drum inside the wheel hub.
The cause of the accident was the brake discs contracting as they cooled, loosening the "grip" of the brake pads.
He has since parked with the car in gear...
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Modern handbrakes are known to be incredibly inefficient and prone to this sort of thing. Long ago the handbrake was supposed to be a secure alternative braking system capable of acting as a fail safe to the foot brake, and able to hold the car securely and indefinitely on a steep gradient. For some unknown reason the required standard has been reduced to the point that it is safer to stick bricks under the wheels.
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Modern handbrakes are known to be incredibly inefficient ..
in repsonse to cliff pope:
so are some designs other than "modern handbrakes" fitted to new cars sold in san-francisco?
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Dalglish - 95%+ certain to be automatics and parked in 'P', for a guess
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Modern handbrakes are known to be incredibly inefficient and prone to this sort of thing.
A bit of a sweeping statement methinks.
The parking brake on my V70 (drums inside the rear disc hubs) is very efficient and will slow this large car down surprisingly well; I have tried it twice so I know how it works if I ever need to do this "for real". The MOT tester actually passed comment on it (effectiveness and balance) and I have used it on a 1:4 slope without problem; the car felt very secure (albeit in first gear too, but then I always leave it in first gear unless parked up to something, and then use reverse instead incase a brain lapse occurs on starting and the clutch isn't depressed!)
Not as good, but still effective, is the parking brake on the Missus' 306 Sedan.
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>>Modern handbrakes are known to be incredibly inefficient
I've always parked my car in gear regardless of whether or not it's on a gradient. Can't recall any incredibly inefficient handbrakes in recent years, though.
Clk Sec
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nearly did the same with my wife's car about a month ago ( X type estate).... was loading it at a friends house, where they have a long gravel drive on a slope..........i heard a clunk and the car started rolling backwards slowly..........luckily i nipped in it and yanked the handbrake up further
could find nothing wrong with the handbrake whatsoever and it hasn't done it since...it seemed like it was on a part of the ratchet that held the car, but for some reason sprung off and moved a couple of places on the ratchet
can only presume that when i set it i didn't pull it on properly and maybe the button wasn't fully out.........(only guessing as i'm not that technically minded)
we both now leave it in gear as well.........which we should have been doing all along of course
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The handbrake cable either isn't tight enough or it wasn't pulled up enough. I personally always leave the car in gear as there then is no question of the car moving, regardless of whether the handbrake is on or off. Unless you could prove that the handbrake is faulty I doubt you could claim off the house insurance as they'd probably put you to blame for it.
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A likely scenario and probably not a fault with the car. You go on a drive, the brakes heat up, handbrake is applied, brakes cool down, discs cool and contract, brakes release enough to get car rolling.
Your house insurance should cover the damage.
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This very afternoon I had to dodge a driverless Corsa that came down a steep hill backwards and ended up through a garden fence. Luckily I was paying attention at the time. My kids thought it was very funny..........
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DiL parked muni 3 weeks ago on the slightly sloping drive - it rolled forward (Forgot to put in gear) and came to rest on the side of my son's Audi TT - no damage to either car but very lucky.
It appears that as the brakes cool down the grip of the handbrake lessens and off the car can go - fortunately at the pace of a snail in the above case.
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From the Highway Code
226: Parking on hills. If you park on a hill you should
park close to the kerb and apply the handbrake firmly
select a forward gear and turn your steering wheel away from the kerb when facing uphill
select reverse gear and turn your steering wheel towards the kerb when facing downhill
use 'park' if your car has an automatic gearbox.
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"park close to the kerb and apply the handbrake firmly
select a forward gear and turn your steering wheel away from the kerb when facing uphill
select reverse gear and turn your steering wheel towards the kerb when facing downhill
use 'park' if your car has an automatic gearbox."
If you did not do this in San Francisco (the turning of front wheels) you could get fine.
But I'd hope on a reasonable gradiant should not be an issue. But I automatically put car in gear on hills and dip clutch before starting even if not in gear.
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Your house insurance should cover the damage.
I thought the car rolled into the garage door and not the house crushed the car
Claiming ? Then it is off the car insurance
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Hi Falkirk Bairn
Yup, the buildings insurance covers this under the section 'impact damage'. Claim now in progress... Car goes back to the garage on Wednesday.
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Cliff P. is about right. For MOT testing, older cars with a single brake circuit have to have a minimum handbrake efficiency of 25% - probably enough to lock the rear wheels from 20mph or so. Modern cars with a split circuit braking system don't need this 'secondary brake' performance, so the minimum efficiency is 16%. - just enough to produce a noticeable 'drag' when handbraking from 20mph. I'm not suggesting that everybody is driving around with braking systems that just meet the legal limits, just that the law insists that old cars have better handbrakes than new cars.
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Cliff P. is about right.
To be pedantic it isn't a handbrake it's a parking brake. Hence only 16%, it isn't required to stop the car when moving. In fact the Jag electronic one can't be used/won't work above 6MPH.
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tr7v8. Ok - park brake. I was talking Tapley meter, still an approved method of testing. Even the Jag wheels must be turning or the car moving to measure braking effort.
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">It is possible that the brake was not pulled right up to the limit<"
I've spent many years pulling handbrakes up as far as they will go, no problems to date.
Steep hill = in gear and a cunningly placed card on the dash labelled "In gear" ...... surprisingly enough.
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The correct technique with disc operated handbrakes is to press the footbrake pedal firmly whilst applying the handbrake. You'll get more pressure from the footbrake than you could ever pull on with the handbrake (e.g 16% mentioned above for handbrake efficiency).
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The correct technique with disc operated handbrakes is to press the footbrake pedal firmly ...
Works with drums as well. Your foot applies the pressure; the handbrake lever (or pedal; don't go there ...) takes up the slack.
But parking on a hill without leaving the car in gear is asking for trouble.
Hawkeye
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Stranger in a strange land
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I would have thought that a handbrake on a modern car (in this case a 2007 Mini) should be more than capable of holding the car on a slope without the aid of putting it in gear as well.
This would lead me to one of two conclusions: Either you didn't pull the handbrake on tight enough for it to remain firm even when the discs have cooled and contracted or the handbrake is faulty in some way.
It is a known fact that hot brake discs will contract when they cool but we are talking about a miniscule amount not milimetres and I maintain that if the handbrake is secured firmly the car will not roll away as the discs cool despite the gradient of the slope.
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Something I've always wondered - how effective is leaving the car in gear? Is there sufficient resistance / compression that the car won't move whatever the slope?
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>>Something I've always wondered - how effective is leaving the car in gear? Is there sufficient
>>resistance / compression that the car won't move whatever the slope?
No, infact you don't need much of a slope to make a car roll even if it is in a low gear. I would estimate that a slope roughly 25-35 degrees is about enough to overcome the resistance within the engine and allow the car to roll away, albeit in a kangaroo fashion. All that leaving the vehicle in gear does is provide a little extra support in conjunction with the parking brake. I am personally not a big fan of leaving things in gear as a matter of course, only when the circumstances require it do I park things with them in gear.
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Depends on g, gearing, compression and whatever else that nice C Enger wants to add.
And friction. Probably.
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I used to always park my 306 with the handbrake OFF, but in gear. It would hold on quite a steep slope. Why this eccentric method, you ask? After leaving the hand brake on for a week the rear foot brake cylinders eased their way to the ends of their travel, allowing all of my brake fluid to dribble onto the road, ruining the shoes in the process. The garage told me this was a well known problem on drum braked 306's.
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For most cars, rear disc brakes are yet another victory of the marketing department over engineering. Owing to weight transfer, many rear brakes are forced to work on reduced hydraulic pressure in order to prevent rear locking. Taking an extreme, anyone who has even MOTd an original mini will know just how little brake effort even a well set up and adjusted rear brake would produce when applied via the footbrake.
That aside, those cars with rear disc brakes and a handbrake acting on an internal drum are IMO well designed. As the metal cools and contracts, the brake is applied harder.
For those who own cars with those awful designs where the handbrake acts on the disc iteself, a check that the car doesn't roll just after you apply the brake isn't sufficient. I would suggest that you *must* take other precautions, such as setting the steering, and putting the car in gear.
Putting the car in gear isn't an absolute lock - it just helps the handbrake a bit. As Bill Payer suggests, given a steep enough hill, the friction and compression may be overcome.
Number_Cruncher
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Depends on g
Local variations in g - that's an eesoteric point to consider!
Number_Cruncher
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Yet another good reason to buy a diesel. They don't roll away when left in gear.
659.
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They barely roll away with foot flat to the floor. I nearly typed "with throttles wide open" but realised that something of vague excitement has nothing to do with deseals.
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g is never constant
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>>g is never constant
Indeed, neither in space or time.
Perhaps the OP might wish to suggest that gravitational waves, resulting from the recently observed super-nova, caused changes in the curvature of spacetime in the region of the rear discs, which resulted in a change in the performance of the brake!!
Number_Cruncher
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In San Francisco they say apply handbrake, leave car in Park (or low gear) and turn front wheels into pavement.
Park, a transmission lock, is the ideal thing for steep hills. If it works it's positive. Can't get worn or out of adjustment like a brake or contract when it cools releasing a gently applied handbrake if it's a disc and trying to distort the drum if the drum is hot and brake applied tight.
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One more query then - bearing in mind what several of you have said about leaving automatic vehicles in park - my other half has a honda civic (auto) which does not have park as an option. As I don't want the other garage door damaged in the same way how should he park his car (i.e. apart from evidently with the handbrake on!)? New garage door on the way incidentally, courtesy of household insurance.
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You need a simple device called a "sprag". It used to be standard on all carts, carriages and early cars, and consisted of a hinged metal or wooden strut that you let down on a bit of cord when parked.
Then when you get out you just put a spoke in the wheel for additional security, and in case the horse decides to walk on .
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One more query then - bearing in mind what several of you have said about leaving automatic vehicles in park - my other half has a honda civic (auto) which does not have park as an option.
Really?
I've never seen an automatic without 'P'.
What age is the car?
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Really? I've never seen an automatic without 'P'. What age is the car?
It's a honda 56 plates clutchless semi-automatic. Options are either neutral or reverse to the right of the gate, plus or minus centrally and auto or manual to the left. I've just been out and checked it to make sure I am not just being a daft woman.
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