Getting rid of brake squeal

5W30 · 23-09-2015 08:18PM #1

Hi all,

My Focus MK2 has brand new discs and brake pads all-round.

I keep on getting brake squeal every time I brake. I took all the pads out, sanded the contact areas and applied copper grease to the contact areas as well as the pad. It made it squeal less for a day or two but now it's squealing again.

What would be the best way to tackle this squeal? What is causing it? It's absolutely doing my head in :pac:

Roger Mellie Man on the Telly · 23-09-2015 10:46PM

Some pad/disc combinations are prone to squealing. If you've fitted OE pads & discs this shouldn't be happening.

biko · 23-09-2015 11:00PM

What brands did you fit? Some pads can squeal before they bed properly.
It really depends on the cause of the squeal, if it's the material or vibrations.

5W30 · 23-09-2015 11:24PM

Not sure about the brand of pads but they are not OE. They came with the car when I bought it. They have definitely bedded in as I've covered 2000 km on them

almostover · 24-09-2015 12:57PM

Put mintex pads and discs in my Vectra SRi recently and it took about 1500miles for the squeaking to go away. The money I saved on the brake components was quickly eaten up by all the nurofen I had to buy!

dutopia · 24-09-2015 12:59PM

5W30 wrote: »

Hi all,

My Focus MK2 has brand new discs and brake pads all-round.

I keep on getting brake squeal every time I brake. I took all the pads out, sanded the contact areas and applied copper grease to the contact areas as well as the pad. It made it squeal less for a day or two but now it's squealing again.

What would be the best way to tackle this squeal? What is causing it? It's absolutely doing my head in :pac:

Literally the exact same as me. Focus MK2 with new discs and pads... squealing all around. Hope someone has a solution.

biko · 24-09-2015 02:55PM

You can try bedding the brakes to see if it settles them faster.

Find an open stretch of road that will allow you to safely reduce speed multiple times

While driving brake gently a few times to warm the pads and discs

When brakes are warm accelerate up to 80/100 kmph and then brake rapidly down to 15kmph - first look behind you! Do not come to a complete stop

Then accelerate up to 80/100 kmph and brake rapidly again - do not stop fully.

Repeat 5 times or so.
Car should not be fully stopped at all during this.

Then drive for 5-10 mins without braking to cool down pads and discs.

This exercise should settle the pads in the calipers and also burn away surface material on the pads and discs.

CJhaughey · 24-09-2015 03:03PM

Try removing the pads and using a metal file lightly chamfer the edges of the pad at a 45° angle. The amount of material you need to remove is quite small just enough to leave a 2-3mm flat bevel.
I have used this to fix squeaky brakes many times.

HardenendMan · 25-09-2015 08:50PM

biko wrote: »

You can try bedding the brakes to see if it settles them faster.

Find an open stretch of road that will allow you to safely reduce speed multiple times

While driving brake gently a few times to warm the pads and discs

When brakes are warm accelerate up to 80/100 kmph and then brake rapidly down to 15kmph - first look behind you! Do not come to a complete stop

Then accelerate up to 80/100 kmph and brake rapidly again - do not stop fully.

Repeat 5 times or so.
Car should not be fully stopped at all during this.

Then drive for 5-10 mins without braking to cool down pads and discs.

This exercise should settle the pads in the calipers and also burn away surface material on the pads and discs.

+1 and I would add that the above "bedding in" should be done by whomever changes the brakes immediately after the job!

Avns1s · 25-09-2015 10:07PM

Take off the callipers and apply a little copper grease to the backs of the pads. You could also remove the pads and apply a small amount to the lugs that sit in the sliders.

Don't overdo it, it doesn't need much and don't let it get on the friction surfaces.

darragh o meara · 26-09-2015 01:30AM

B3 careful where you apply the copper grease, I seen a fella who put it on the friction surface.... Solved his squeaking problem alright !!! But didn't help his breaking

5W30 · 27-09-2015 03:37PM

Avns1s wrote: »

Take off the callipers and apply a little copper grease to the backs of the pads. You could also remove the pads and apply a small amount to the lugs that sit in the sliders.

Don't overdo it, it doesn't need much and don't let it get on the friction surfaces.

Did that already, that was the first thing that came to mind.

I will try bed them a bit, if it doesn't help I'll add a chamfer :mad:

Hal1 · 29-09-2015 11:07AM

Use silicone grease on the slider pins and were the caliper slides (top & bottom). Apparently it can cause corrosion and it contains metal particles that when under high temps can interfere with abs signals.

bbability · 29-09-2015 06:34PM

Hal1 wrote: »

Use silicone grease on the slider pins and were the caliper slides (top & bottom). Apparently it can cause corrosion and it contains metal particles that when under high temps can interfere with abs signals.

Have a similar issue on my Avensis at the minute. Fitted Mintex pads and discs at the same time. Found the sliders on one caliper not to be moving freely during the service. The brakes just squeak at the bite point and at no other time. I took the slider pins out again and gave them another clean. One of them is not moving as free as the other so I would say its not applying equal pressure. I believe its important to use the white lithium grease on the slider pins as other types can gunge up a bit.

rex-x · 29-09-2015 07:53PM

Brake squeal is caused by the pads vibrating while being applied but before fully pressurised against the disc(hence is only brief), brembo 4 pots are particularly bad for this. Copper grease will do nothing to help, its normally the pads being slightly too small for the retainer they are in (person fitting shaved too much off to make them fit "freely", cheap brand etc).

5W30 · 29-09-2015 07:58PM

rex-x wrote: »

Brake squeal is caused by the pads vibrating while being applied but before fully pressurised against the disc(hence is only brief), brembo 4 pots are particularly bad for this. Copper grease will do nothing to help, its normally the pads being slightly too small for the retainer they are in (person fitting shaved too much off to make them fit "freely", cheap brand etc).

Yeah I will probably go for OE pads next time. I had no choice with the current brakes as that's what the seller had put on. Still could be worse, at least they work :pac:

5W30 · 30-09-2015 08:16PM

Finally got the brake squeal sorted. The culprit brake pads were the front ones. They were completely chamfered and it was a flat surface. When I removed the wheel I could see the brake dust immediately built up around the edges of the friction material.

Took the pads out, filed around the edges to make them like a good set of brake pads and the noise has disappeared completely.

I couldn't find out the make of the brake pads because the backside was too rusty.

Rear pads were chamfered and probably a different make?

Getting rid of brake squeal

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