Brake disc screw

[Baz999]

I was cleaning out the holes in the brake discs and noticed that the retaining screw was missing from both disc, will this be ok be driving for nearly a year now with no problems.

Could this cause some of the vibration when braking?

Baz

[RS6BRIT]

No. The screw simple stops the disc falling off when you remove the wheel. The wheel and it's bolts supply the clamping force that holds the disc solid. The vibration is a build up of pad material on the disc face. The brakes need to be used very hard to avoid this, but most of us suffer vibration as it's hard to use the brakes hard in every day use.

[R1RS4]

Yes the screws retain the disc, but play an important function

They hold the disc face close to the location face on the hub, ie when assembled to the the disc and hub the mating faces must be kept clean, without the screws, "if" the disc moves forward when removing a wheel road dirt and debri can fall between the locating faces and throw the disc and road wheel out of true, for the cost of the screws clean the faces and refit them.

When you say vibration on braking;

Do you have "any" vibration when driving normally without braking?

What condition are the disc faces? Ie any scoring?

Are you running spaces?

[CellDamage]

Also a pain if you're re-fitting a wheel and the disc PCD rotates out of line with the hub!

They're about 30p each from Audi.

[Baz999]

I will get some screw. It was a pain drilling out the pad material and the holes got out of alignment. Discs are fine no marks they were brand new about 7 months ago.

I do try and brake as late and hard as possible, aslo when finishong work doing some hard stops from a high speed which does ease the vibration when braking.

[Lukes3]

What pads are you using?

[Baz999]

I don't know what make they are. When i got the car the dealer had put new front discs and pads

[Lukes3]

Ok. Well just thought this would help, when i got my rs4 there had been some cheap front pads fitted (between 60-100 qwid cheap)
I was getting terrible vibration hard braking used make it a bit better but soon came back,so i thought it was the discs an looked in to getting new ones.
Long story short i brought some yellow stuff pads an it has never happened since 12 momths down the line used every day on same discs an its all good.

[Baz999]

It wasn't an audi dealer so may well be cheap pads. Might look at trying some new pads see if that helps

[RS6BRIT]

It really is hit and miss. I fitted new discs and Yellow stuffs when I got the car as it had large lips on the discs. It didn't have any vibration before but now it does. The yellow stuffs are great pads however, stop very well and low dust (compared with OE). And before someone suggests that the hubs weren't clean when I fitted them, or that I didn't fit the screw. I did. On both counts.

[Surrey Sam]

Guy's, if you purchased new discs through Audi and they have warped again in less than two years. Get them replaced under the 2 year parts warranty - I did with no problems.

It's also worth checking for corrosion under the metal plates where the pads locate onto. If corrosion is present there, it will then start to pinch the pads and stop them sliding back and forth from the friction surface.