High pitched noise from Brakes when not under breaking
Discussion
Morning all, hopefully someone may be able to assist.
My car has developed a very loud high pitch squeal when the brakes (Brembos) are not being used. It generally happens after 10-15min of driving (I assume once things have warmed up) and then is a constant high pitched noise.
Under braking the noise stops and the pedal feels fine. If I stop for a minute the noise goes for a short time but then comes back.
The dealership say the brakes just need a clean but did that yesterday at a friends garage and if anything it’s made it louder.
There was nothing really concerning about the pads or discs although there was some rubbing on the disc. And looks like the pad is not using the full surface area.
Before I change the pads and discs is there anything I should be looking at?
My car has developed a very loud high pitch squeal when the brakes (Brembos) are not being used. It generally happens after 10-15min of driving (I assume once things have warmed up) and then is a constant high pitched noise.
Under braking the noise stops and the pedal feels fine. If I stop for a minute the noise goes for a short time but then comes back.
The dealership say the brakes just need a clean but did that yesterday at a friends garage and if anything it’s made it louder.
There was nothing really concerning about the pads or discs although there was some rubbing on the disc. And looks like the pad is not using the full surface area.
Before I change the pads and discs is there anything I should be looking at?
Pads look like an old & a newer one, so could be mis-matched, disc wear looks a bit uneven and possibly high-ish.
If the discs are expensive (don't know the car) and the thickness is OK get them skimmed, fit a full new set of pads to match, when you have the calipers off make sure pistons are free & greased with silicone grease, make sure the correct new shims/springs are fitted & you should be good to go.
If the discs are expensive (don't know the car) and the thickness is OK get them skimmed, fit a full new set of pads to match, when you have the calipers off make sure pistons are free & greased with silicone grease, make sure the correct new shims/springs are fitted & you should be good to go.
When I had this on the 911, it was because the Pistons were not being pulled back slightly by the pistion seals. They are designed to flex out slightly when you brake, then pull the piston back to stop the disk being held against the pad. A large amount of gunk had built up under the dust seal and this was holding the piston out.
To fix I had to pop the Pistons out and clean up the barrel and piston.
Popping Pistons out using a bike pump works well, hold one side in and pop out the other, then reinstall and do the remaining ones. Just don't use your fingers as a piston can pop out with some force !
Use new seals and dust seals. Mine had a very small amount of corrosion at the top of the piston on the bit that sits outside the seal, scrape any off but be very careful not to scratch the piston in any way.
To fix I had to pop the Pistons out and clean up the barrel and piston.
Popping Pistons out using a bike pump works well, hold one side in and pop out the other, then reinstall and do the remaining ones. Just don't use your fingers as a piston can pop out with some force !
Use new seals and dust seals. Mine had a very small amount of corrosion at the top of the piston on the bit that sits outside the seal, scrape any off but be very careful not to scratch the piston in any way.
E-bmw said:
Pads look like an old & a newer one, so could be mis-matched, disc wear looks a bit uneven and possibly high-ish.
If the discs are expensive (don't know the car) and the thickness is OK get them skimmed, fit a full new set of pads to match, when you have the calipers off make sure pistons are free & greased with silicone grease, make sure the correct new shims/springs are fitted & you should be good to go.
Pads are the original brembo pads from new (23,000miles) the discs seem to have ribs almost across the whole surface which seems odd. If the discs are expensive (don't know the car) and the thickness is OK get them skimmed, fit a full new set of pads to match, when you have the calipers off make sure pistons are free & greased with silicone grease, make sure the correct new shims/springs are fitted & you should be good to go.
Gary C said:
When I had this on the 911, it was because the Pistons were not being pulled back slightly by the pistion seals. They are designed to flex out slightly when you brake, then pull the piston back to stop the disk being held against the pad. A large amount of gunk had built up under the dust seal and this was holding the piston out.
To fix I had to pop the Pistons out and clean up the barrel and piston.
Popping Pistons out using a bike pump works well, hold one side in and pop out the other, then reinstall and do the remaining ones. Just don't use your fingers as a piston can pop out with some force !
Use new seals and dust seals. Mine had a very small amount of corrosion at the top of the piston on the bit that sits outside the seal, scrape any off but be very careful not to scratch the piston in any way.
This is what I think is happening it feels like it’s not releasing far enough as the sound goes when stopped. To fix I had to pop the Pistons out and clean up the barrel and piston.
Popping Pistons out using a bike pump works well, hold one side in and pop out the other, then reinstall and do the remaining ones. Just don't use your fingers as a piston can pop out with some force !
Use new seals and dust seals. Mine had a very small amount of corrosion at the top of the piston on the bit that sits outside the seal, scrape any off but be very careful not to scratch the piston in any way.
Will look to doing this.
Had exactly the same problem on my Fiat Coupe a few years ago and tried everything to find it, symptoms were identical. After swapping things around, rebuilding calipers and putting new flexis on I kicked myself when I found the problem....
When putting things back together again for the umpteenth time I noticed a very small horizontal crack on one of the brake pads (when looking side on), cleaned the pads up properly and gave the crack a proper prodding to..pad promptly crumbled away. These pads were genuine Fiat and only a few thousand miles old, quick google says I'd overheated them at some time (most probable) or the pads were defective.
As the pad warmed up it was obviously distorting through the heat and coming into contact with the disc hence the noise. Changed the pads and noise never came back again. I'd bet you've got the same problem, you'll need to look really closely at your pads as the cracks will be very hard to spot.
Been in a convoy with you as well so know your Abarth doesn't hang about
When putting things back together again for the umpteenth time I noticed a very small horizontal crack on one of the brake pads (when looking side on), cleaned the pads up properly and gave the crack a proper prodding to..pad promptly crumbled away. These pads were genuine Fiat and only a few thousand miles old, quick google says I'd overheated them at some time (most probable) or the pads were defective.
As the pad warmed up it was obviously distorting through the heat and coming into contact with the disc hence the noise. Changed the pads and noise never came back again. I'd bet you've got the same problem, you'll need to look really closely at your pads as the cracks will be very hard to spot.
Been in a convoy with you as well so know your Abarth doesn't hang about
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