Technical Ultra Loud Squeal Noise From Rear Wheels (not under braking)

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Technical Ultra Loud Squeal Noise From Rear Wheels (not under braking)

knightsofmeltonia

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Hello all,

My Abarth 500 has developed an extremely loud squealling noise from the nearside rear wheel whilst driving. The noise is intermittent in that it doesn't occur during every journey, but when it does happen, it doesn't last the whole journey - it will last for quite a few miles on both straight and twisting roads. Varying the speed does not alter the noise. Braking makes the noise stop.

At first, the noise would stop if the steering wheel was turned to the right, but start up again when the wheel was straightened. But now the noise happens whatever the steering wheel position. I have jacked up the car, spun the wheel but found no sound (as I said, it doesn't happen all the time), and had a look at the brake pads. The wheel in question has no more than 3mm left on the pad whilst the offside has slightly more (strange?). Can't see or feel anything else that looks unusual around that wheel.
I'll change the pads but wondered if there might be something else causing the noise? If it was the pads making the noise, I would have expected it to occur during braking, not to stop during braking. Any ideas on what might be at fault?

PS. Milage is at 30k.

Thanks in advance
 
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Does it stop if you touch the brake pedal very gently, not enough to really slow the car but just enough to make the pad touch the disk. If yes try taking the pad out & clean away the dust & replace the pad with a bit of copperslip on the back of the pad where it touches the piston in the calliper



Another thought, some pads have brake wear sensors, a small piece of spring steel attached to the pad & when the pads are nearing worn out they start to rub on the discs making a squeeling sound, Im not sure if Abarth use this & if at 3mm left it would start making a noise, I know this noise will be made when the brakes are not applied.
 
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This is now a common problem on A500`s around 2 years old.(I am sure DF will be on soon)
The problem is the pads stick with brake dust.Also there will be a ridge of rust on the disc, which is where the squealing is coming from.
The problem is also exacerbated by the self adjust mechanism for the handbrake which is designed to maintain a close contact of pad to disc.
The squealing will be worse when brakes are hot (and therefore dry) as any little clearance tightens up.
Soloution:Remove pads and s/steel locators,clean off rust and dust.Reassemble with a little copaslip on moving surfaces,ensure pads move easily in the caliper!
Also remove ridge of rust on disc or fit new.
Just done mine,good as new now.
 
I had exactly the same problem and solved it just as Goldback suggests. At first I thought it was a wheel bearing but a simple clean up of the rear brakes solved the problem.
 
Thanks for all of your input. It is very much appreciated.
I too thought that it may have been a bearing issue, but from the sounds of it, a simple clean up of the brake parts is all that is needed. That sounds good to me. Will get on to it tomorrow and let you know the results.

Incidentally, does anybody know the minimum pad thickness before replacement is needed? Most of my other cars have been 2-2.5mm.
 
Just got back from my local dealer with much the same problem and they basically refused to anything about it. I know what the fault is (sods law none of the intermittent issues showed up today) and even said as much but their stance was if it doesn't do it in their presence they won't touch it.
 
Jimbro: which dealer did you use? I'm thinking that I might have to use my dealer if I don't have any luck sorting it myself. Trouble is, the noise isn't constant and it's sod law that it never occurs when a mechanic is around.
 
We only have one dealer in Manchester so I'm sure you can work that out without me posting it on here and angering the gods of FiatForum.

I would go back to the dealer I bought the car from but they are too far away to be a simple visit and while my local dealer is being friendly (if not entirely helpful) then it just isn't feasible.
 
Can you please let me know what are the steps to remove the rear break pads? Because on the front it is pretty easy just need to remove the clip and the fixing pin then undo the bolt fixing the brake caliper.
On the rear there is no pin but there is another bolt instead. So all I need to do is just undo the 2 bolts, am I right? Thanks for the help in advance
 
Just an update for you all. I took the rear brakes apart and gave everything a clean. The noise didn't disappear. Took everything apart a second time and gave it all a super clean, especially the two steel clips that the pads slot into. This seemed to do the trick and I didn't have any noise for a few days. But the peace didn't last :(.

The cleaning work that I did was just to the rear (both sides). I now suspect that the noise is now coming from the front as it only occurs when I turn the steering wheel to the left, and having passed a parked car whilst the noise was occuring, the echo from the squeal could be heard as soon as the front wheel passed the car.

I can appreciate why having clean clips helps to keep the noise at bay. It would appear that the pads are designed to slide in these clips so that when the brakes are not being applied, the pads are free to back away from the discs. If the clips are gunked up with muck, the pads can't slide and they rub on the discs, creating heat and noise (my theory at least).
After doing some test drives between cleaning, it was apparent that the discs were getting hot even on short runs - my OSR disc needing flushing with water on one drive when it became super-hot!!!!! :eek::eek::eek:
The more I cleaned them, the cooler the brakes got after the test drive, so it must be working.

Incidentally, the Abarthisti forum are running a similar thread. I turns out that this is a VERY common issue and the dealers need to know about it so that they can report it to Abarth in Turin (hopefully to have the fault investigated properly and then rectified). Some people are finding that their dealers are replacing the affected brakes with brand new items for free, others are having to pay for the repairs. Seems a bit daft if it's a known fault - it ought to be free. Dealers can only do anything and report it if they can hear the squeal for themselves, but as this is an intermittant problem, that might not be too easy, and a hassle if like me you live miles from the dealer.
I have noticed though that the noise occurs when the brakes are dry and warm - ie. after a long run and not in wet weather. Any water makes the noise disappear immediately, so choose your trip to the dealer when the weather is fine.
I'll do the front brakes and report back when I know where I stand with this.
Dylan.
 
Dylan - You are totally correct in what say about the pad clips.However if there is any rust on the caliper behind the clip and rust on the ends of the pad the clearance will still be tight.
It seems that the design holds the pads very well(too well!) and brake dust acts like superglue. I had to use a light blow with a hammer to remove mine!
It may be worth creating a bit more clearance by removing say 0.25mm off the ends of the pads.
It will be interesting in the fullness of time to see what they come up with to fix this problem.
 
Another update. Before I got a chance to look at the front brakes, we decided to take an impromtu trip to Research at Nuneaton when the noise began again whilst driving down the M1. We figured that if we could get the car to the garage whilst the noise was occuring, they might be able to diagnose the fault. Typically though, twenty minutes before we arrived at the garage, the noise stopped. :rolleyes:

Research took a look and said that the brake pads had worn to their limit and that was why the noise was occuring. I did spot that the NSR pad was 3mm thick and the OSR was 4mm thick when I was cleaning them, and I knew they would need changing very soon, but I would not have assumed that the thin pads were causing the hideous squealling sound.
Anyway, Research changed them for £120 :eek:, and the noise has stopped. That was four hundred miles ago. Time will tell if that was the actual cause of the problem or not.
 
Since having new discs/pads fitted, the noise has obviously gone on mine too. 1000 miles in, no noises but it was a good 15,000 to 25,000 miles before mine started initialy.

Seems unfair some are having to pay £340 for new brakes (me!) and others are getting them changed under warranty...
 
I heard of a few people getting the pads changed under warranty as it happens to quite a few of these cars from 3,000 miles, I'm off to the stealer today and going to make them do it, the car has 10,000 on it now and it has drove us mad all that time. I'm loosing faith in these cars, might sell it!
 
It is annoying but the problem is simple to resolve.
Removing the pads, lightly sliding the friction surface over some abrasive paper on a flat surface and refitting after cleaning and applying copper grease to the contact surfaces worked fine for me. (Obviously not the friction material contact surface, although that would definitely solve the problem ;))
Did this at 4,000 miles and now I'm at 10,000 odd miles and still silent.
 
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