Judder - pulling (remaining) hair out

[Volvian]

I've reviewed other threads on this topic, but I have a couple of nuances that are confusing the hell out of me. I've got a UK 10-plate XC90 D5 Exec; a year ago I started to experience quite extreme judder when braking gently from high speed (c.60mph+). This was primarily felt through the steering wheel (not pedal) although the vibration passed through the whole car. Local garage diagnosed warped front discs and replaced them. Problem went away for about 6-weeks and then reoccurred (same symptoms). Back to garage and front discs replaced under warranty (bless them). Problem solved, but 6-weeks later I'm back at the same place. Garage has checked pads (fine), calipers and parking brakes (not sticking). The only fault they've detected is that the rear nearside disc is warped out of tolerance, and have advised replacement. I'll do this, but doesn't seem to explain why this problem has previously been temporarily alleviated by replacing the front discs (or why I'd feel the judder through the steering wheel)? Braking otherwise feels fine - responsive, no fade, etc. Thoughts, similar experiences, remedies welcome please!

[gmonag]

Are you using genuine Volvo discs and pads? If not, do so.

Warped discs are probably a myth most of the time and the problem is more likely due to contamination of the disc/pads or incorrect fitment of the disc (not square on the hub). I had the same symptoms a while back (judder under light braking) but it cleared after a while. Try some heavier braking.

Also check suspension/steering bushes and ball joints.

[Moose Test]

Originally Posted by gmonag

Are you using genuine Volvo discs and pads? If not, do so.

^^ That.

Originally Posted by gmonag

incorrect fitment or the disc (not square on the hub)

^^ And that. Possible that there is rust between the hub and inner disc face leading to untrue runout.

[Volvian]

Thanks @gmonag @Moose Test

No, using pattern parts (I was offered Volvo replacements, but was clearly feeling tight that day). :-) I'll use Volvo parts moving forward.

Runout on all discs is within tolerance, except NSR (0.12mm vs. 0.05mm max). Confusing thing is that problem temporarily went away went front discs replaced, but these seem to be OK (OSF 0.01mm and NSF 0.025mm).

I'll change the rear discs to see if that helps.

[Rooster]

I had a OSR caliper stick on my xc90 and wear the pads nearly down to metal,

It was a sunday so i just got a set of pagid rear pads from a motorfactors, the caliper was replaced and all was good for a while until i started to feel a brake vibration that go worse and worse to the point where braking from 70mph plus i physically couldn't hold the steering wheel,

Strange this was though when i was towing it was fine and didn't shake wheel at all which i found strange,

I checked runout and found rear discs to be well out of spec,

Replaced rear discs, pads and handbrake shoes with genuine stuff and its been fine since