Thread: new discs and pads.. now super noisy

this squeal is back. if i dont drive my car for a few days then itl be silent for the first 10-20kms then the noise well come back.

So its 3 different sets of pads in the rear.. all have made noise. Done 7000km since the discs were changed and probably 5k km since i fitted these genuine pads. Definitely not bedding in!

It wont make any noise in reverse.. ie if i drive forwards even slowly & brake it squeals like buggery, in reverse its silent.

Yes the pads are fitted the right way, as are the shims... last time round i got so frustrated i coated everything but the working faces with copper grease in the hope that it would help... but no such luck didnt make a difference.

Obviously it isnt the pads as i have tried 3 diferent sets and now genuine and it made no difference. could it be the discs? I dont know what brand they are but they were brand new as well when the noise started. im struggling to understand how it could be the disc as its really just a slap of metal...but that is the only thing i havnt changed.

Anymore ideas anyone? its driving me mental!

I hope this helps! I had the same problem when I purchased my second hand 1997 110!

Some history!

Brakes started to squeal, just like you said, almost unbearable! I replaced the disks and the pads. Squeal disappears for a couple of thousand on k's, then returns!

How I fixed the problem and some theory which fits the observation!

Ok so initially I has just re-assemble the caliper as I found it. The anti-squeal plate sitting not bonded between the pad, and the caliper piston. With the older caliper, I noticed that the harmonics were created but the piston worn in a way which allowed the brake pad to start to wear at an angle other than perpendicular to the brake disk.

This angle I found would wear on both side, and effectively making the the brake pad ever so slightly convex(curved outwards), only enough to create the harmonic, you could not see it just by looking!

Anyway, how I fixed the problem!

Bought new pads! Bonded the shim/anti-squeal plate onto the brakepad using engineering grade silicon. Then inserted the pad assembly into the caliper with enough silicon to bond the pad assembly to the piston. Enough silicon means that when the caliper is relaxed, the pad assembly still is attached to the piston.

Assembled both sides like this, as soon as they were assembled, I applied heavy brake pedal pressure, then left it overnight to cure before driving.

25000 km's later no noise.

My theory is that the silicon allows the pad and squeal plate to always align in a worn caliper? Maybe I'm completely wrong, but it worked for me.

I know how bad it can get, I was seriously ready to sell the Defender!

Hope this helps!

Hi there Chris,

Changed the pads on my TD5 as they were getting to the end of their life. The elcheapo's squealed like crazy, replaced with Bendix 4x4 pads and it still squealed. I had to get my rotors machined to get rid of the glazing.

I know you mentioned that you fitted new rotors and pads. If the first set of pads glazed the rotor then it will keep on squealing even with proper pads. Have a look at the braking surface of your rotors.

Hope you can silence it soon.

Cheers, Jurgens.

Originally Posted by inken_dave

I hope this helps! I had the same problem when I purchased my second hand 1997 110!

Some history!

Brakes started to squeal, just like you said, almost unbearable! I replaced the disks and the pads. Squeal disappears for a couple of thousand on k's, then returns!

How I fixed the problem and some theory which fits the observation!

Ok so initially I has just re-assemble the caliper as I found it. The anti-squeal plate sitting not bonded between the pad, and the caliper piston. With the older caliper, I noticed that the harmonics were created but the piston worn in a way which allowed the brake pad to start to wear at an angle other than perpendicular to the brake disk.

This angle I found would wear on both side, and effectively making the the brake pad ever so slightly convex(curved outwards), only enough to create the harmonic, you could not see it just by looking!

Anyway, how I fixed the problem!

Bought new pads! Bonded the shim/anti-squeal plate onto the brakepad using engineering grade silicon. Then inserted the pad assembly into the caliper with enough silicon to bond the pad assembly to the piston. Enough silicon means that when the caliper is relaxed, the pad assembly still is attached to the piston.

Assembled both sides like this, as soon as they were assembled, I applied heavy brake pedal pressure, then left it overnight to cure before driving.

25000 km's later no noise.

My theory is that the silicon allows the pad and squeal plate to always align in a worn caliper? Maybe I'm completely wrong, but it worked for me.

I know how bad it can get, I was seriously ready to sell the Defender!

Hope this helps!

Thanks for the good write up! One question though; what happens when these pads are worn & you need to change them? Going to be hard work getting them out of the caliper if theyre siliconed in?

Originally Posted by BST4X4XFA

Hi there Chris,

Changed the pads on my TD5 as they were getting to the end of their life. The elcheapo's squealed like crazy, replaced with Bendix 4x4 pads and it still squealed. I had to get my rotors machined to get rid of the glazing.

I know you mentioned that you fitted new rotors and pads. If the first set of pads glazed the rotor then it will keep on squealing even with proper pads. Have a look at the braking surface of your rotors.

Hope you can silence it soon.

Cheers, Jurgens.

Thanks, il try Daves technique if that doesnt help i will look at getting the discs machined. They probably are glazed, in fact i tried smoking them in a bit in an effort to reduce noise (worked short term but not long term!)

Originally Posted by chris_mack

Thanks for the good write up! One question though; what happens when these pads are worn & you need to change them? Going to be hard work getting them out of the caliper if theyre siliconed in?

If you use engineering silicon, just two flat bladed scredrivers will bring the pad out of the caliper while tearing the silicon from the piston only!

I know this because I had experimented with one wheel, found the solution as described before, and applied it to all wheels, with all new pads!

no problems!

Just clean surface before and after with a petrol based solvent, but dont use it near the caliper, dust cover, or caliper piston seals!

Originally Posted by chris_mack

Thanks, il try Daves technique if that doesnt help i will look at getting the discs machined. They probably are glazed, in fact i tried smoking them in a bit in an effort to reduce noise (worked short term but not long term!)

Before I found my solution, I had roughened the disks/padsw, tried to grove the pads to change the natural frequencey, and other things to the disk which I wont record here! Nothing helped unit I bonded the pad assembly using brand new pads!

It started to click when the squeal would always disapear when I installed new or machined PADS! After a while it always came back!

it does sound like you had exactly the same problem as i have.

so il get some new pads (again!) later in the week & give it a go.

Fingers crossed!