Vibration Under Braking, help please!

[Barneyk]

Hello all, I’m after some help/advice on what the cause of vibration when braking may be. XC90 2.4 D5, 2010, 150k miles. I’m getting vibration at speeds of over 50mph when braking. It’s a steady and consistent vibration, which gets more aggressive at higher speeds or by pressing down harder on the pedal. It feels like it’s coming through the brake pedal, but the whole car has a distinct ‘thumping’ noise so it’s quite hard to narrow it down to a specific area. Could anyone suggest what I’d be best to check through first to find the source of the issue? Thanks!

[Clan]

Originally Posted by Barneyk

Hello all, I’m after some help/advice on what the cause of vibration when braking may be. XC90 2.4 D5, 2010, 150k miles. I’m getting vibration at speeds of over 50mph when braking. It’s a steady and consistent vibration, which gets more aggressive at higher speeds or by pressing down harder on the pedal. It feels like it’s coming through the brake pedal, but the whole car has a distinct ‘thumping’ noise so it’s quite hard to narrow it down to a specific area. Could anyone suggest what I’d be best to check through first to find the source of the issue? Thanks!

I would suggest it is worn bushes on the lower front suspension arms.. amplifying some slight brake vibration so you might want new front brake discs and pads too. Get genuine volvo front suspension arms as cheap ones flex at a different rate and can cause the car to pull to one side when accelerating or Braking.

[Tannaton]

^^^^ what he said… also has the car been laid up recently? If it’s not been driven for a month or more the discs can corrode but tend not to where the pads are in contact with it, when the car is used again most of the surface rust gets scraped of but some of it gets polished and that leads to a situation where some parts of the disc surface have a surface with different friction properties from the rest, hence the vibration. Try doing 5 or 6 hard stops from 60 mph (with a few mins between the let the brakes cool) see if that improves it.

If it is the above it would likely show up on a mot brake roller test

[Barneyk]

Originally Posted by Tannaton

^^^^ what he said… also has the car been laid up recently? If it’s not been driven for a month or more the discs can corrode but tend not to where the pads are in contact with it, when the car is used again most of the surface rust gets scraped of but some of it gets polished and that leads to a situation where some parts of the disc surface have a surface with different friction properties from the rest, hence the vibration. Try doing 5 or 6 hard stops from 60 mph (with a few mins between the let the brakes cool) see if that improves it.

If it is the above it would likely show up on a mot brake roller test

Thanks for the advice guys, I’ll have a look into that! It’s not been laid up since I bought it, and it didn’t seem to be prior to that from what the service history says. Appreciate the help!