In Saturday's Telegraph, HJ's column quotes a letter from a luckless couple who had total brake failure in their Daewoo Nexia. I understood it to be based heavily on the Vauxhall Astra, in which case it should have dual circuit brakes. If that's true, then the car should have stopped by application of the footbrake, not by the parking brake as the piece stated.
I have never had the experience of dual circuit brakes failing; presumably you get more pedal travel and uneven baking. Anyone care to share their experiences?
Madame's Singer Chamois (Hillman Imp) did let go the front to rear brake pipe years ago when I was driving, but I managed to stop without incident on the handbrake, and I have had a front to rear pipe go in an old Citroen CX (dashboard lit up like a fairground, hydraulic pump chattered away, gallon of green fluid on the road) but it still stopped on the footbrake.
Any comments, ladies & gentlemen?
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Darcy,
I thought that as well. Unless you're really unlucky and a couple of brake pipes are split at the same time, the only way you could get a sudden and total brake failure is if the brake pedal disconnects from the master cylinder.
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I had a hairy moment in a Land rover - which had been reversed- not by me - over a heap of rubble, the brake lines are routed along the back axle and one had been damaged, which caused the fluid from the circuit to be lost, unfortunately the warning lamp didn't work and the land rover and a trailer with a mowing machine on failed to stop on a very steep descent, the handbrake didn't seem to help much so we had to hit a wall to avoid a worse collision. Nobody was hurt and the wing was straightened out using the faithful birmingham screwdriver ( Hammer).
The scenario described in Saturdays Telegraph could happen but it is a very unlikey one. the brake fluid warning light would come on if any fluid was lost.
Perhaps the unlucky person didn't know what this meant.
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Eh? In reply to Marcus, if the brake pipe was ruptured, the first attempt to brake would pump the fluid out BEFORE the brake warning light came on to warn of low fluid. If you are travelling at 20 - 30mph and the brake warning light come on to tell you that you have no brakes you could, of course, attempt to stop with the parking brake. But on a Nexia this operated on a disc brake, so isn't very effective.
HJ
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Does this answer the question re dual cct? I would have expect some braking to remain if only to cause a pirouette (or however it is spelt!).
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And while we are on the subject of no brakes, what about the Vectra hand brake. This is the most useless piece of utter utter trash I have ever come across, but sure that others can come up with better examples.........or do I mean worse examples? You know what I mean.
It works using 2 tiny shoes using the hub like a brake drum. The manual tells you to apply the brake and drive slowly for a distance every so often to clean the surfaces. If you do this the brake is then so ineffective its not true, dread to think about MOT time. Yet if you leave it and just apply it when the car is absolutely stationary, then it gets cacked up, grabs and sticks on. Grizzle grizzle grizzle.
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Stuart
Never had any complaints about mine - worked a treat and I never did bother to clean the shoes. A cable adjust or two at service time was needed though - not on the schedule, but my dealer did it anyway. Is this the problem you have?
Don't forget that it's drum brake because using a disc brake as a parking brake has a big problem. When the hot discs cool they contract and relax the parking brake load, which makes it a potential runaway sucess if you see what I mean. A drum brake produces the opposite, and safer, effect.
Cheers
John
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I have heard a whisper from a very reliable source today concerning the possible effects of disinfectant used on vehicles and flexible rubber brake hoses. It seems that repeated application of disinfectant COULD have an adverse affect upon the rubber construction of the flexible hoses......leading to brake failures.
Needless to say, my technicians will be looking very carefully at flexible brake hoses at service time - as we are in one of the most heavily infected areas
I don't know the actual composition of disinfectant and possible effects upon rubber compounds - is there anybody out there in the know??
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If disinfectant is affecting brake hoses, the manufacturers should talk to the wellington boot makers. No-one seems to have had their boots rotting away
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John,
The cable adjust has been done on all the services so far bar one.
The problem with mine is that if you do not clean the shoes and pull on the handbrake as you kill the last 0.1mph of speed in pulling up, the handbrake is just too effective, the shoes grab and the wheels immediately lock solid. There is no part way, they are either off or FULL ON! (The severity of the grabbing means that if you are so minded they are quite effective for handbrake turns ;-) Plus you can then get the brakes locking on overnight so there is a bit of rocking needed to free them off, especially if the days previous journey was in the soaking wet.
But if you do as the manual says and clean the shoes I find the handbrake effectiveness is v v poor. It can even run away on our drive unless I have 3 Shredded Wheat before pulling on the lever.
What you seem to be saying is that its not an inherently bad system and maybe I have got one that needs a bit more TLC.
BTW talk of inefficient handbrakes and running away leads nicely into X*****s.
rgds,
Stuart
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Stuart
Yes the brake on my car was either off or on, and if you used when moving it came on with a bang, but it did work well as a parking brake.
Is the overnight locking definitely the handbrake, or is it the main brake pads rusting to the discs...
Cheers
John
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In answer to Stuart, you know what the fix was for X*****s? They filed the bottom lugs off the parking brake ratchet so that driver had to put the parking brake on properly or it didn't work at all. Fortunately the Highway Code now tells drivers to leave cars in gear, so no more faked Watchdog horror stories about runaway X*****s.
HJ
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HJ,
I am sure this is an excuse for David W to put us right but I remember hearing from a Citroen engineer whose car had run away after the ratchet mod admittedly on a very steep dealer forecourt and against first/reverse gear. His theory that it was something to do with the angle of dangle of the various bits in the linkage after the suspension had subsided. Hence X*****s now have this valve which stops the suspenders drooping like BX's. Then again this might be a load of cobblers, and its all a bit irrelevant as whatever it was its now solved.
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Stuart,
The Xantia's have a cable handbrake to the front wheels. I would not expect this arrangement to be affected much by vehicle height. The disc cooling issue was more important.
Ever watched a Xantia on the MOT rolling road. Staggering brake performance from the handbrake, well in excess of the required footbrake efficiency. Apart from the times when the tester drops the rear on the rollers and pulls up the handbrake with a fleeting look of "failure"......before he says "sorry mate, wrong end".
My understanding of the "anti-sink" suspension (provided by an additional sphere between the rear wheels) was consumer feedback...people just didn't like them being flat to the road in the morning. They wanted a "proper" car.
This anti-sink arrangement on the later cars does have a drawback, as the suspension height correctors don't go through the overnight stretch they are prone to seizing links.
Having said that most of the Citroens that do sink overnight bear the scars underneath of hurried getaways in the morning. A driveway gate keeper or small kerb can tear off half the exhaust under these circumstances.
I actually like the character of the "real" ones that sink. And a small anti-theft tip......
Leave the car in manual low height. If it is nicked within a hundred yards the ride with no suspension will get the guys to abandon in favour of a proper car they understand.
David
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David
You should know nothing could be worse than the Citroen CX for handbrake failure, no-one knew how to adust them properly, lots of rivet-hinged links to rust and wear and the pads themselves were the size of 50p pieces AND the discs shrank when cooling ;-(
However, you could steering-lock the front wheels at an angle to the kerb - if you remembered.
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If I remember back 15 years the trick was to correctly adjust the handbrake pads/links then take up the remaining slack on the cables. What people used to do in reality was forget the actual brakes and keep taking it up on the cables.
Result ever more stressed cables pulling on ever less efficient brakes.....or did I dream that?
David
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David
Absolutely right.
The ultimate was to get the cable end so short it felt from the driving seat as if the handbrake was on tight, but it was actually pulling against the linkage. I can reveal (modestly) that I was a champion CX handbrake adjuster (grin), but it always took ages, whereas the goons who just did the cables could be finished in minutes.
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Darcy Kitchin wrote:
>
> David
>
> You should know nothing could be worse than the Citroen CX
> for handbrake failure, no-one knew how to adust them
> properly, lots of rivet-hinged links to rust and wear and the
> pads themselves were the size of 50p pieces AND the discs
> shrank when cooling ;-(
>
> However, you could steering-lock the front wheels at an angle
> to the kerb - if you remembered.
Brings to mind my 1964 Pug 404 that had a sort of umbrella style handbrake lever hinged from the side of the steering column (opposite side to the column change gear lever). The ratchet on mine was so badly worn that if you got out of the car and slammed the door, the handbrake flew off of its own accord.
I always carried a housebrick in the passenger footwell and put this behind the tyre, before shutting the door firmly.
What's a ratchet, you may ask? It's big mouse s**t.
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Had the front brakes on a Fiat 127 fail once years ago due to the pads coming out of the caliper. But they were down to the metal. DOHHH!!
Bill
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had the front brakes on a bike, GSX750, fail once. Actually, they didn't fail so much as fly off. When the mounting bolts let fly I was lucky the caliper flew off rather than jamming between the wheel and the forks.
Took a very, very, long time to stop
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Wow this brings back memories. Remember those Commer vans, the ones where the track on the front axle looks too narrow, still see a few Dormobile conversions, were they Karriers? Coasters? Oh hell I forget.
Anyway handbrake is on front wheels there too. Apologies in advance to boys in blue for this one. but roadside inspection, examiner jacks up rear wheel , pulls handbrake on, of course it spins freely, got a certain conviction here he thinks. Puts a Tapley meter in the footwell, (it was some time ago) and of course the test drive nearly stands it on its nose. doh!
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