Brake suspension noise xc90

Luckylow10

Hi, I put this up on some Volvo groups, but thought I’d throw it up here see what ideas I get.

My new to me 2019 t8 xc90 is making squeak/creak sound when coming to a stop, only on hill (for now). It’s quite loud and embarrassing , the brakes don’t feel rough or make any other sounds normally, it’s only when I’m on a little decline and I’m inching forward.

The brake pads were checked and are apparently fine. I also bounced the car at the front and rear and no sounds came from it.

Thanks

https://youtu.be/iqX9KFft7_U

punisher5112

Copper grease on the pads.... If they're bone dry at the back they could squeak.

Actually sounds like the metal backing plate behind the discs.

Luckylow10

How would the backing plate make that sound?

Tea drinker

I'll be controversial and ask is it possible there's contamination (or glazing) on the disc / pads, maybe from cleaning.
Should dissapear with driving. Otherwise try copper grease back of the pads.

Another slim possibility is if the car was standing for a long time before you got it might be rust got cleaned off the disc by the pad and is lodged in there. A power hose would shift it.

Dirty Nails

Luckylow10 wrote: »

How would the backing plate make that sound?

Resonance. Noise emits from the backplate from likely a bit of brake judder.
Tuning fork effect.

BavarianCare

Luckylow10 wrote: »

Hi, I put this up on some Volvo groups, but thought I’d throw it up here see what ideas I get.

My new to me 2019 t8 xc90 is making squeak/creak sound when coming to a stop, only on hill (for now). It’s quite loud and embarrassing , the brakes don’t feel rough or make any other sounds normally, it’s only when I’m on a little decline and I’m inching forward.

The brake pads were checked and are apparently fine. I also bounced the car at the front and rear and no sounds came from it.

Thanks

https://youtu.be/iqX9KFft7_U

Please don't use copper grease - use Ceratec - copper grease should never be used anymore, we are not in the 80s (BUT that is not your issue)

It's easy to find cause of that noise - use a pit, not a lift obviously but it sounds like:
(BEAR IN MIND I DON'T HAVE EXPERIENCE OF THESE MODELS)

1. Protection plate
2. Stone (debris)
3. Dry/worn joint

Luckylow10

I brought it to Volvo today we went out for a drive and I showed them the video, and they said it’s a “characteristic of the vehicle” and “ they all do that” . They will take it in to have a look and see if they can improve it..

Luckylow10

Dirty Nails wrote: »

Resonance. Noise emits from the backplate from likely a bit of brake judder.
Tuning fork effect.

That makes sense, and is there anything that can be done to dull the sound of the resonance?

Dirty Nails

Luckylow10 wrote: »

That makes sense, and is there anything that can be done to dull the sound of the resonance?

As someone said above,lubricate the back of the pads,the garage will prob do that.
In the meantime you could try a screwdriver through the wheel on to the backplate over & under the caliper. Hitting a flood hard enough could be enough to distort them. Just give it a gentle nudge inwards - don't get carried away at it. Even if it changes the tone,you'll know you're on the right path.
Only do it on the wheel thats making noise.

Tea drinker

Some people add weight to the backing plate, if it's a characteristic of your expensive car then Volvo should be aware and perform this for you.
Contact Volvo (not dealer) and tell them you are annoyed by the noise and are any fixes planned.
An easy and reversible way to add weight would be sticky weights used for balancing wheels.
That's if copper grease doesn't fix it.

Luckylow10

I will see what they say when they have a further look I have found a technical bulletin or TJ about it and the proposed fix but this is for the USA and Canada..

dkd21

Unfortunately its more predominant in hybrid vehicles as the brakes are not used as often due to regenerative braking but some harder stops from a high to low speed every so often to give a transfer layer on the discs will reduce the ''grabbing'' effect and will help quell the noise