The GFs Astra H is suffering from a distinct vibration through the steering wheel whilst braking over 35. No pulsing felt through the pedal. Discs and pads just a few thousand miles old. Definitely front axle related.

I will be replacing the discs and pads this week...short of that, is there anything else worth checking? Have given both wheels the 12/6 and 3/9 tests without finding anything, although still not 100% sure if I have ruled out the track rods/TREs.

I've asked on the respective forum too, but they're not quite as astute (shocker)

Any advice would be much appreciated

 

Wheels balanced?

Could be shocker related, could be crap on the discs. Could be cheapo discs....

 

I think you've covered it all there, but more than likely warped discs first, could be a TRE or a inner rack end but it would be enough play for you to pick up at 3/9

 

Could be front wishbones (well, bushes that have worn). Bearings also a possibility.

I wouldn't bother replacing discs/pads if they're only a few thousand miles old. Chances are it's not that.

Discs don't really "warp" as such (it takes a LOT to warp iron!), the (misleading) description often really means pad friction material sitting (unevenly) on the disc. Garages can clean/skim the disc to remove the build up.

 

They might be aftermarket crap with runout like an old record?

Check the faces are clean.

If it is cementation, a bout of spirited driving with a long cool-down period might help. The Prelude tends to suffer from it occasionally, if repeatedly braking for too many poxy roundabouts from high speed.

Also, try swapping tyres front/rear. The heavily-laden fronts can 'collapse' a bit after a while.

 

Whenever I've had this sort of thing it's turned out to be tyres. In fact I think I had it when I had an Astra, though that was a 1990 Astra.

 

Warped or run out as Nick suggests is more likely to appear on newish disc's that haven't being bedded in properly or the drive
flange that hasn't being cleaned properly or a binding brake, a build up on the disc can usually be felt on the pedal and can as 'Dracoro' suggest's be cleaned up, but you can always check the run out first with a dti

possibly a wishbone bush but if it was enough to make the steering shake then you would feel the movement when slow speed braking,

wheel bearing again to shake the steering would have enough play to feel at 12/6,,3/9

 

a wheel bearing would usually be noisy too wouldnt it?

i had a xsara vts which had over assisted brakes, that used to buckle discs. it was a pos though.

 

After market or oem?

No problems before they were replaced? If not it would be a big coincedence if something else was causing vibration just after you replaced them.

Have you checked you haven't lost a balance weight on one of the wheels?

 

Cheers for the suggestions chaps

Balancing is fine.

Discs and pads are extremely cheap and crappy ones...new ones aren't. I'll check the hubs are clean etc before sticking them on.

It's due its MOT soon, so will hopefully rule out/confirm wishbones or track rods/ends then.