5008 mk1 steering wheel vibration when breaking at speed

[amazighman]

Hi all.

I have been chasing the cure for this annoying problem on my 5008 mk1 , When I am breaking sharp at moderate to high speed I get this steering wheel vibration shaking symptom.

When I bought the car the control arms were worn so I replaced them with stuff from ebay but that did cure the shaking.
I then bought TRW control arms and fitted them and that didn't fix it either

There is no play at the front wheels when moved by hand , I also fitted new brake discs and pads all around last year.

Could it be the braking system is the issue? I am puzzled
Thanks

[PaulC5]

When you replaced the discs did you check the run out was within spec ?

[amazighman]

When you replaced the discs did you check the run out was within spec ?

No i didn't , i have a gauge but i hate using the thing.
One side the retaining screws were missing , I fitted the disc without them for few months before I got some and retaped the thread and put new screws

[johnnyh]

If the mating face of the hub which the discs rest against is rusty you can get run-out even with perfect discs. Get a wire wheel in a grinder and go over the face of the hub till it is "shiny".

[amazighman]

If the mating face of the hub which the discs rest against is rusty you can get run-out even with perfect discs. Get a wire wheel in a grinder and go over the face of the hub till it is "shiny".

I always make sure the hub is spotless.
Nevertheless I have used the dial guage and found there is 0.13 mm runout on the discs...
The outside surface of the discs look good , however both look worn on the inner side.
I bought a set of Febi discs and pads and some replacement caliper guide pins .

[johnnyh]

Logically:
if the problem was there before the discs were changed,
and the discs were mounted on good clean hub faces,
and the problem was still there afterwards,
the problem is not the discs or their mounting.

However, if now there is that much run-out then what could have caused it ? Sometimes a car that doesn't get used much can rust behind the pads as the moisture hangs around there for a long time and when the car is next used the rust is quickly worn away leaving the disc very slightly thinner in that spot. Repeat till noticeable.

[PaulC5]

In the Haynes manual for the C5 it gives the max disc runout as 0.05 mm so you are well over that. When fitting new discs I clean the hubs up with a flat file and then fit the discs with wheel bolts with large nuts under so they can be done up and then check the runout. If the runout is high just rotating the disc on the hub is usually enough to sort it. Might take a few minutes but is a lot less than having to do the job again if the brake pedal vibrates.

I usually use discs from a dealer, quite expensive but the quality is good and I would have thought Febi ones should also be good.

[amazighman]

In the Haynes manual for the C5 it gives the max disc runout as 0.05 mm so you are well over that. When fitting new discs I clean the hubs up with a flat file and then fit the discs with wheel bolts with large nuts under so they can be done up and then check the runout. If the runout is high just rotating the disc on the hub is usually enough to sort it. Might take a few minutes but is a lot less than having to do the job again if the brake pedal vibrates.

I usually use discs from a dealer, quite expensive but the quality is good and I would have thought Febi ones should also be good.

Glad you mentioned the max runout , I thought it was 0.10
Thank you very much

[PaulC5]

You might be right for your car, in a Haynes manual for an Astra 2009 to 2013 it gives 0.1 mm.