Safe Speed Forums

Oh yes you do!!!

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When I see an adult on a bicycle, I do not despair for the future of the human race. H.G. Wells
When I see a youth in a motor car I do d.c.brown

When said "well known" firm had a tyre offer I rang-up to get a price, to be told .....so I asked them what types where on offer. They wouldn't tell me. I rang-in with several enquiries but never did find what tyres WERE on offer.
But, if you want REAL rip-off prices, buy motorcycle tyres.
Bought-in tyres are priced at £42.00 and sold for £110.00, each.

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The world runs on oil, period. No other substance can compete when it comes to energy density, flexibility, ease of handling, ease of transportation. If oil didn’t exist we would have to invent it.”

56 years after it was decided it was needed, the Bedford Bypass is nearing completion. The last single carriageway length of it.We have the most photogenic mayor though, always being photographed doing nothing

Who said it was British? It's French junk!!

My car has a brake wear warning system. When they are worn out, they make a grinding noise that is far more obvious that any light!

PS: whenever I read " I thought almost all cars had them", my heart sinks. They load cars with more and more garbage each year. It's the death knell of simple and robust engineering. I want a car, not a space shuttle, to haul stuff back from the hardware store!

I'm confused...

Half the time people on here are moaning their backsides off about the complexity of modern cars and the uselesness of al lthe "whistles and bells" they have.

And yet, for all the massive added complexity of...

...a piece of wire and a bulb....

Somehow pad wear warning lights are a bad idea????!

Had the OP been able to benefit from the luxury of such a device, he would have know several hundred miles BEFORE he ended up stuck a long way from home with little choice of repair venue, that he'd be needing new pads!

My car is 18 years old and it has them (AND (one side) still works)! I can't be bothered fixing the broken wire as pads always get changed in axle sets anyway.

Seriously though, don't most cars built in the last 10 years have them?

If I had to choose between that and a bluetooth stereo with IPOD docking station and electric belly button warmer, I wouldn't have to think very hard!

I don't need pad-wear warnings. I look at them every few months. Less than 4 mm and they get changed. If you wait until the grinding noise your maintenance checks are bad.
As for brake discs, the wear limit is stamped on the disc. Hardly rocket science. If there is a noticeable lip then the chances are that the wear limit has been, and gone.
I can get a set of discs for 22 quid.....that's both sides, front. Pads are 13 quid, both sides front.
Complete replacement, both sides, takes about an hour.
MOT tests will soon be measuring the wear on discs, at the moment they just look at them.
My motorcyle MOT uses vernier calipers to check the wear against the manufacturers data now.
(the bikes wear limit is 0.4mm wear on a disc 6mm thick)

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The world runs on oil, period. No other substance can compete when it comes to energy density, flexibility, ease of handling, ease of transportation. If oil didn’t exist we would have to invent it.”

56 years after it was decided it was needed, the Bedford Bypass is nearing completion. The last single carriageway length of it.We have the most photogenic mayor though, always being photographed doing nothing

If only it were that simple, Mole. There's a sensor, which fails. Sometimes it goes off too early, making you buy brake shoes before you need them. Sometimes it goes to late, and you wreck your disks anyway. Sometimes it doesn't go off at all.

It hooks up to software. The software must be changed. The sensor and the software changes have to be paid for. The console must be redesigned, the fuse box must be redesigned. The wiring harness must be redesigned. The subcontractors manufacturing and supply chain systems must be re-engineered. The spares department must now stock two versions of the instrument console. Then there's another change, and it needs 3, 4 or 5 copies of the same piece. Then a bug is found in the software. The car is called back into the dealers. And so it goes on; a decent design degrades into a great steaming pile of rubbish, over time. Because of a brain fart about a piece of wire and a bulb....

I don't do maintenance or checks, apart from the lights, tyres, oil and water. And the MOT. It's not worth it for bangers. If I find myself doing too much checking, I try to find something else to be getting on with.

Quite!

Oh, and you also missed out the fact that many "Warning lamp" systems dont actually have wear sensors on "all" the pads! You can guess which pads invariably wear down to the metal first!

IME/IMO the best brake pad warning systems are the ones with the little springy piece of metal that protrudes about 1/16" beyond the edge of the backing plate and contacts the disk when the pads get this worn.

It then makes a horrid noise but without doing any damage.

No bulbs!

No wires!

No sensors!

No computers!

Costs almost nothing!

(One day, perhaps, ALL cars will be built this way!!)

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"The road to a police state is paved with public safety legislation"

A 1/8" copper strip also does the job. It's softer that the disk, so it can't gouge it. Simple, elegant, almost perfect (except for deaf drivers!) And it makes a mockery of the designers who would change the instrument panel for something so simple. Yet the Christmas light brigade is winning out, sadly.

The copper strip would be too soft and not heard from inside the car before wearing out. The strips that dusty is talking about are sprung steel and give the warning noise like the one that you probably heard. You may not have needed to change your pads on the day in question, you would probably have got another few hundred miles out of them if it was just the warning strip that you heard. Some earlier cars also have a warning light that triggers when the brake fluid level falls (as it does as the pads wear and the callipers extend more. Unfortuantely this doesn't work too well if the fluid level is topped up interim.

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My views do not represent Safespeed but those of a driver who has driven for 39 yrs, in all conditions, at all times of the day & night on every type of road and covered well over a million miles, so knows a bit about what makes for safety on the road,what is really dangerous and needs to be observed when driving and quite frankly, the speedo is way down on my list of things to observe to negotiate Britain's roads safely, but I don't expect some fool who sits behind a desk all day to appreciate that.

Anything is better than more electronic rubbish. But the manufacturers love planned obsolescence, so they load up the panel with bogus lights to gouge a lot more cash out of us. Things have been going to pot since the 80's. If anything, motoring is dearer now than it was then. We're going backwards, in a welter of computers, wires and nick-knacks.

Is that really true????

Here's how mine (and as far as I'm aware, every other one I've ever seen) works.

The pad has a "sensor" in it. The "sensor" is, in fact, a piece of wire set into the friction material a set distance from the backplate. It comes "free" with the pad (although, it's true that if I were to buy the set for the version of my car that DOESN'T have pad wear indicators I'd save a quid (per axle). As I do all my own maintenance, I save far more than that on fitting costs, so I don't really care and I splash out on the expensive ones.

The wire that comes out of the pad is connected to a cable that goes up the inner wheelarch to the instrument cluster. It then goes along a printed circuit board to a bulb. From the bulb it goes back to earth through the disc. There are no "computers" anywhere to be seen in that system. Whether or not more modern offerings have the increased level of complexity that you mention, I don't know. But it's certainly not necessary. I guess that a possible refinement of the system would be to make it "latch" so that the light doesn't flicker irritatingly as it makes and breaks contact with the disc. That could be something that a manufacturer might choose to do IF there was already a central control computer being used for other things. I somehow doubt, however, that the pad wear warning light system would justify a computer all of its own though.

What I probably also ought to say, however, is that becuase mine is an old car, I have the wheels off so often that I don't think I've ever actually changed a set of pads when the light comes on. I tend to change them at about 2/3 thickness to try and preserve my horrible sliding brake callipers from working at maximum extension. When it was new though, I would have thought it would have been a useful feature. I don't like waiting until I hear the sound of the backplates graunching away at the discs, because (a) it doesn't do the discs any good and (b) my brakes won't be working at their best. But I guess it would save the cost of a bulb and a piece of wire!

I'm always a bit wary of really cheap discs. I've seen some "no-name" ones in the past and the quality of the castings has been pretty awful. Surprisingly, one doesn't really hear much about crashes caused by poor quality safety-critical stuff, so I guess it can't be much of an issue, but on something so safety-critical, it always nags at the back of my mind! OK, that doesn't mean to say I'd go off and spend £300 on genuine ones, but I tend to try and go for something from a manufacturer I've heard of. Anything that doesn't have a batch number and a manufacturer's name or logo on it I tend to walk away from.

None of it is necessary, like Dusty says. After Star Trek, cars got more lights on them, because the marketing boys needed gimmicks. And the public were gullible enough to think they were necessary. Think of it as "electronic go-faster stripes". They've never been straight ever since.

Now you can't buy just a car - you know, four wheels and an engine. You have a buy a truck load of electronic crap with it as well. And it's never really yours, anyway. The software in under license. You can never own the whole car, now. Some of it always belongs to the makers.

That's because almost no crashes are caused by the hardware. It's almost always driver error, not hardware faults. I once heard the figure due to failure was around 1%. That's why you don't hear much about it - it hardly happens.

Yet it gets more attention than driver training. What a waste, but it makes pots of money for the makers.

I'm with Mole on the simplicity of Brake Pad warning lights - there's no complicated "sensors" at all.

It's just a copper wire through the pad at the lower depths. When fitted, this wire conducts electric. When worn down, the wire is broken, circuit broken, and hey presto, a warning lamp comes on!

If you can these pads for your car, then this must be the simplest and easiest after fit you could do yourself - just complete the circuit to somewhere convienient in the dash.

Lucy, you could wire them into your rear fog lights and become a numpty......lol

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My views do not represent Safespeed but those of a driver who has driven for 39 yrs, in all conditions, at all times of the day & night on every type of road and covered well over a million miles, so knows a bit about what makes for safety on the road,what is really dangerous and needs to be observed when driving and quite frankly, the speedo is way down on my list of things to observe to negotiate Britain's roads safely, but I don't expect some fool who sits behind a desk all day to appreciate that.

To show you just how OTT you can go, the iDrive system diagnostics give a remaining brake pad life estimate in miles!

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Malcolm W.
The views expressed in this post are personal opinions and do not represent the views of Safespeed.

How does it do that? Is it merely an estimation from usage like a TC overheat cut-out?