I thought I'd post this here as there's lots of people who know about the greasy stuff on a car...

In the last 3 and a bit years since passing my test, I haven't activated the ABS/locked the brakes on a car once yet it's happened twice on my Aygo in the last week, which leads me to think it's the car. Once was pulling upto the stop line at a roundabout, braking no harder than usual from about 10-20mph as there had previously been a car in front. The other time was following a line of traffic at the same sort of speed, the traffic in front slowed quickly and I braked firmly but no harder than I usually would. The bunched-up cars in front stopped without drama yet my ABS came on. Can anyone offer a suggestion on this?

Also, my brakes have been squealing for the past few weeks, I'm assuming this indicates brake pad wear? And could low pads = more ABS activation?

I bought the car from Toyota used in September and haven't put more than a few thousand miles on it. No idea if the pads were fresh when I bought it...

Thanks

I think you've answered your own question, never ignore noises from or change in behaviour of the brakes! It's likely worn friction materials could be biting randomly if the surfaces are warped.

Is it actually feeling like it's braking harder?

In my old fiesta you could stamp on the brakes and they might eventually bring you to a stop - I nearly threw my passenger through the front windscreen the first time I stopped in my new Golf :/

Thanks for the help! When the ABS comes on it doesn't seem to be stopping any quicker, I'd assume it'd be a hard, sudden stop but it slows at a "normal braking" pace.

The brakes feel okay, I am quite hard on them though so I'll get my pads checked this weekend. Wouldn't be surprised to find warped discs...

[rant]Can't wait to be shot of the thing in summer and get an MX-5, to be honest. The niggles on the Aygo are starting to annoy me, which is a shame as it's great fun on a sunny day on the twisties. Unfortunately, the gearbox is rubbish and the engine needs to be worked hard to get any power, which knackers the fuel economy... And on the motorway, fuel economy takes a nose dive as it's revving so high at 70ish and needs full throttle to maintain that speed up an incline...[/rant]

I don't know much about anything, but I think putting some copper grease on the back of the brake pads (not the braking surface ) should stop the squealing.

Yeah, that's the other thing that was suggested to me. I might get the brakes checked by Toyota when it goes in for this throttle recall thing (yay, another niggle!)

Quote from JO53PHS :

I don't know much about anything, but I think putting some copper grease on the back of the brake pads (not the braking surface ) should stop the squealing.

It's important to distinguish the difference between squealing (nothing to worry about normally solved by a bit of copper grease), clunking (normally nothing to worry about caused either by pads loose pads moving about or floating discs moving about) and grinding (metal on metal, a truly terrifying noise that sooner or later will kill you).

Yeah, it's definitely squealing not grinding.

If the noise is the brake pad wear indicators, you should really get new brake pads. If you don't change them and wear them down until there's noting left, you'll most likely damage your disc brakes after that... which will result in needing new discs, and not just new brake pads.

Braek squeal can be caused by the pad surface being worn in an odd way, or having the grooves in the pad filled with dust. Be worth taking a wheel off and trying to judge how much pad you have left - more than 5mm is fine, less than 5mm will become a worry in a few months.

If you can, perhaps remove the pads one-by-one, and clean out the slots, then refit with copper slip on the back (do not let any copper slip touch the disc or friction face, and you only need a tiny amount of grease that is almost see through).

It is possible (though, I admit, highly unlikely) that the squeal is causing a vibration that is tripping the ABS.

Might I suggest you find a clear, empy road (or an old airfield), and practice braking REALLY REALLY hard, so you can see when and how the ABS kicks in. You will learn a lot, and it'll be useful when you get your decent car (the MX-5)

a lot of cars have audible wear indicators, they're just spring metal that touches the disc when the pads are worn down and these could be what you're hearing. however since you say the AVS is activating as well there is the possibility that the noise is because the friction area of the pad has gone completely. this means that brake will be doing less so the duty of slowing the car is spread amongst the other wheels raising the loads on the tyres, this can result in one or more of those becoming close to lock up, hence the ABS activating. heavily warped / worn discs can have the same effect.

whatever get the brakes looked at, not being able to go is inconvenient, not being able to stop can be far more serious.

EDIT: when you say the ABS is activating, do you mean you're getting a warning that it is or is it just the pedal that is vibrating? if it's just the pedal then it may actually be warped discs that you're feeling

Quote from TiJay :

Thanks for the help! When the ABS comes on it doesn't seem to be stopping any quicker, I'd assume it'd be a hard, sudden stop but it slows at a "normal braking" pace.

ABS isn't really about stopping quicker, it's about stopping in a more controlled manner. Lock all four wheels and Isaac Newton's doing the steering for you. With ABS you can still steer the car.

It was on the news this morning. Toyota brakes aren't working properly. IIRC they are currently recalling the priuses (good just crush the shit heaps :razz

Quote :

when you say the ABS is activating, do you mean you're getting a warning that it is or is it just the pedal that is vibrating?

The pedal, steering wheel and car are vibrating as they do when it kicks in.

Quote :

ABS isn't really about stopping quicker, it's about stopping in a more controlled manner. Lock all four wheels and Isaac Newton's doing the steering for you. With ABS you can still steer the car.

That is true, what I meant is I'm not really braking hard enough to give it a reason to come on.

Quote :

Might I suggest you find a clear, empy road (or an old airfield), and practice braking REALLY REALLY hard, so you can see when and how the ABS kicks in.

Yeah, I will. The problem is it's kicking in when it didn't in the past under the same conditions, unless I've grown a heavy right foot in the last week. Which is possible!

So the conclusion so far is knackered brakes of some kind... Great I will look at the pads and grease them in necessary.

Luke: I thought that was just the Prius?

Quote from TiJay :

The pedal, steering wheel and car are vibrating as they do when it kicks in.


That is true, what I meant is I'm not really braking hard enough to give it a reason to come on.


Yeah, I will. The problem is it's kicking in when it didn't in the past under the same conditions, unless I've grown a heavy right foot in the last week. Which is possible!

So the conclusion so far is knackered brakes of some kind... Great

Luke: I thought that was just the Prius?

Sounds like your Aygo is having the same problem. Try contacting a toyota dealer it may turn out the Aygos are going to be recalled. Or that the problem extends past the prius

Re: Toyota carpets and brakes, see Sniffpetrol this month. Very funny pisstake of the situation...

Quote from Luke.S :

Sounds like your Aygo is having the same problem. Try contacting a toyota dealer it may turn out the Aygos are going to be recalled. Or that the problem extends past the prius

There is no "problem" with the Toyotas and Lexuses brake pedals. It's down to a retarded American panicking when the cars carpet jammed the Accelerator on, and instead of turning the Engine off, he decided to ring 911....

Quote from Nathan_French_14 :

There is no "problem" with the Toyotas and Lexuses brake pedals. It's down to a retarded American panicking when the cars carpet jammed the Accelerator on, and instead of turning the Engine off, he decided to ring 911....

nothing to do with brake pedals. It was on the news this morning the Priuses in the Uk are possibly being recalled due to faulty abs which is coming on at the wrong time. And it sounds like the problem TiJay is having with his Aygo

Here

And Here