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?
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.
Gassing Station | Suspension, Brakes & Tyres | Top of Page | What's New | My Stuff