Not joined yet? Register for free and enjoy features such as alerts, private messaging and viewing latest posts and topics.

Shaking steering when braking

Discuss problems you have had or are having with your Z4
User avatar
Smartbear
Lifer
Lifer
Posts: 13685
Joined: Wed Feb 05, 2014 6:54 pm
Location: a barn in Somerset

Shaking steering when braking

Post by Smartbear » Sun Jan 15, 2017 8:42 pm

Scooba_Steve wrote:If they were installed with runout yes, but given the age of the cars I'd expect bushings to be failing - check the front control arms or get someone to do it as the first step.
Engage the steering lock & try to rock the wheel whilst holding it at 3oclock & 9oclock :thumbsup:
Rob
Image

e89 Sdrive 20i, plenty of mumbo & good economy-the thinking bears z4
e89 Sdrive 30i, this ones busted, pass me another...
e85 3.0si sold

User avatar
GuidoK
Lifer
Lifer
Posts: 3171
Joined: Tue Aug 17, 2010 1:37 am
Location: all over the place

Shaking steering when braking

Post by GuidoK » Sun Jan 15, 2017 8:47 pm

Fanatic wrote:
But my discs are new. Is it possible that new discs can have this problem?
Yes they can.

I suspect warped discs or that the mounting hub wasnt properly cleaned when the discs were installed.
You should use a dial indicator (you know, on a magnetic base) to measure any offset wobble (I think a swivel style dial indicator might be the easiest to use here). If there isnt any offset wobble, front control arm bushings or control arm ball joints could be a problem
Z4 3.0i | ESS TS2+ | Quaife ATB LSD | Brembo/BMW performance BBK front/rear | Schrick FI cams | Schmiedmann headers+cats | fully polybushed | Vibra-technics engine mounts | H&R anti rollbars | KW V3 coilovers | Sachs Race Engineering clutch

User avatar
Fanatic
Member
Member
Posts: 119
Joined: Mon Feb 07, 2011 12:25 pm

Shaking steering when braking

Post by Fanatic » Sun Jan 15, 2017 8:49 pm

Scooba_Steve wrote:If they were installed with runout yes, but given the age of the cars I'd expect bushings to be failing - check the front control arms or get someone to do it as the first step.

The new rotors were coated when new. Is it possible that the coating has not completely been removed and has a runout? It has been 2000-3000km since though.
04' Z4 2.5i Maldives Blue - 108 alloys - Hardtop - 3,0si brakes F/R, BMW sport stubby, K&N filter, chrome exhaust tips, ZHP shift knob, cruise control, sound generator, twin clear reverse light, led dome light and footwell lights. :driving:

Paulwirral
Member
Member
Posts: 914
Joined: Sat May 17, 2014 8:28 am

Shaking steering when braking

Post by Paulwirral » Sun Jan 15, 2017 8:55 pm

Bed them in aggressively , blue hot and drive home the long way round .

User avatar
Fanatic
Member
Member
Posts: 119
Joined: Mon Feb 07, 2011 12:25 pm

Shaking steering when braking

Post by Fanatic » Sun Jan 15, 2017 9:02 pm

Paulwirral wrote:Bed them in aggressively , blue hot and drive home the long way round .
How many km do they need to bed in? I have done about 2000km
04' Z4 2.5i Maldives Blue - 108 alloys - Hardtop - 3,0si brakes F/R, BMW sport stubby, K&N filter, chrome exhaust tips, ZHP shift knob, cruise control, sound generator, twin clear reverse light, led dome light and footwell lights. :driving:

Paulwirral
Member
Member
Posts: 914
Joined: Sat May 17, 2014 8:28 am

Shaking steering when braking

Post by Paulwirral » Sun Jan 15, 2017 9:39 pm

There's 2 different schools of thought on this subject , I've always done a dozen or so emergency brake routines , 70mph down to walking pace then drive home carefully while they cool off , the brakes will stink , and I've never had a problem on any car with this method .
However , there's an equal amount if people do the , brake very lightly for the first 1000 miles or so .
It's your choice , but it's free , and the only time I ever had a problem with fade or vibration was when I used the light brake method .
If it doesn't work obviously you need to check the bushes , if they are ok you can get the discs skimmed on the hub , pro cut I think it's called , I has it done once on floating discs , i was surprised at how much needed to come off the disc considering I couldn't really feel anything through the car .

User avatar
Fanatic
Member
Member
Posts: 119
Joined: Mon Feb 07, 2011 12:25 pm

Shaking steering when braking

Post by Fanatic » Sun Jan 15, 2017 9:59 pm

Paulwirral wrote:There's 2 different schools of thought on this subject , I've always done a dozen or so emergency brake routines , 70mph down to walking pace then drive home carefully while they cool off , the brakes will stink , and I've never had a problem on any car with this method .
However , there's an equal amount if people do the , brake very lightly for the first 1000 miles or so .
It's your choice , but it's free , and the only time I ever had a problem with fade or vibration was when I used the light brake method .
If it doesn't work obviously you need to check the bushes , if they are ok you can get the discs skimmed on the hub , pro cut I think it's called , I has it done once on floating discs , i was surprised at how much needed to come off the disc considering I couldn't really feel anything through the car .
Thanks for the info. I put ferodo Premier on and they squeak when the warm up. Sounds like things have not yet settled with the brakes/rotors.
04' Z4 2.5i Maldives Blue - 108 alloys - Hardtop - 3,0si brakes F/R, BMW sport stubby, K&N filter, chrome exhaust tips, ZHP shift knob, cruise control, sound generator, twin clear reverse light, led dome light and footwell lights. :driving:

Post Reply