Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: flyer 0712 on 30 November 2014, 22:38:10

Title: wheel and brake wobble
Post by: flyer 0712 on 30 November 2014, 22:38:10
A friend of mine just bought an omega...The problem is at approx 50mph it has slight wheel vibration and on easy braking there is a slight vibration coming up through the brake pedal just as if the  a.b.s system is making  the brakes go..on/off..on/off on.off....With heavier braking this disapears and feels ok...The brakes are spot on and there are no a.b.s warning light to say the unit is faulty.....fitted new genuine front discs and pads and then had the wheels tracked and balanced..flew through m.o.t...with no advises......if the steering geometry camber/angle/whatever  is out would this cause these two symptoms...thanks  :y
Title: Re: wheel and brake wobble
Post by: Broomies Mate on 30 November 2014, 22:48:09
Possibly, but 50MPH is about where you start to notice wobble from an imbalanced wheel.

Swap front wheels to back and see if the problem gets better or worse.

Slightly buckled wheel, perhaps?  :-\
Title: Re: wheel and brake wobble
Post by: chrisgixer on 30 November 2014, 22:56:32
The wishbone bushes are fooked.
Title: Re: wheel and brake wobble
Post by: flyer 0712 on 30 November 2014, 23:45:00
Wish bones are perfect,,just past m.o.t...and he has already changed front wheels to back,,,,all four wheels were checked for buckles when tracked..this is why it is baffling...cheers. :y
Title: Re: wheel and brake wobble
Post by: chrisgixer on 30 November 2014, 23:53:18
...any wobble through the steering?
Title: Re: wheel and brake wobble
Post by: Nick W on 30 November 2014, 23:57:18
If you've physically checked the wishbones, and ensured that all four wheels and tyres are round then I would put worn shocks at the top of the list. But before investigating those, have another look at the wishbones.
Title: Re: wheel and brake wobble
Post by: Diamond Black Geezer on 01 December 2014, 08:55:31
Yup. Srry to say just having passed MoT doesn't mean the wishbones / the car is perfect. Exhibit A = you've got a wheel wobble/vibration. Be a bit brutal, let the wheels hang, try getting a long lever in and prying / pushing the wishbone in directions it doesn't like. You can't just have a quick look, sometimes a stuffed/torn bush only shows up once you've removed the whole wishbone.
Title: Re: wheel and brake wobble
Post by: flyer 0712 on 01 December 2014, 17:29:38
Today went around to him...he had car jacked up and with brute force and a great big bar   found no play at all in the wish bones..which dont look that old as still see the black paint very well..or any steering joints,,,.I took it for myself for a drive and yes around 50mph slight frront wheel vibration but on braking at 50.mph with hand on top of automatic gear lever the vibration comes up the lever quite harshly     ,,,so any ideas  :-\
Title: Re: wheel and brake wobble
Post by: tigers_gonads on 01 December 2014, 22:40:02
Any play in the front wheel bearings or lips on the discs ?
Title: Re: wheel and brake wobble
Post by: Kevin Wood on 01 December 2014, 22:42:59
Sounds like brake disks out of true to me.
Title: Re: wheel and brake wobble
Post by: flyer 0712 on 01 December 2014, 22:58:40
no lips on discs as they are new,,,,,,they were changed because of this problem but it remains....however will tell him to check the the new discs just in case   thanks   :y :y
Title: Re: wheel and brake wobble
Post by: Kevin Wood on 01 December 2014, 23:17:34
OK.. But it could be that they aren't seated flat on the hubs due to debris, perhaps?
Title: Re: wheel and brake wobble
Post by: flyer 0712 on 01 December 2014, 23:41:29
Ok  will help him strip them out to hubs and start again and then he will know they are correctly seated  thanks  :y
Title: Re: wheel and brake wobble
Post by: Seth on 01 December 2014, 23:45:05
A friend of mine just bought an omega...The problem is at approx 50mph it has slight wheel vibration and on easy braking there is a slight vibration coming up through the brake pedal just as if the  a.b.s system is making  the brakes go..on/off..on/off on.off....With heavier braking this disapears and feels ok...The brakes are spot on and there are no a.b.s warning light to say the unit is faulty.....fitted new genuine front discs and pads and then had the wheels tracked and balanced..flew through m.o.t...with no advises......if the steering geometry camber/angle/whatever  is out would this cause these two symptoms...thanks  :y

Master cylinder. Just sorted one with same symptoms ;)

Bleed the entire system first though, and then you'll probably find it's spot on ... for a few days ;)
Title: Re: wheel and brake wobble
Post by: flyer 0712 on 01 December 2014, 23:49:15
Ok seth thanks will check that out   :y
Title: Re: wheel and brake wobble
Post by: flyer 0712 on 02 December 2014, 00:05:37
Just interested....seth...if by bleeding the system may cause it to work ok for a while and then it  starts to do it again,,,,what would be wrong with the master cylinder to make it do that..thanks  :y
Title: Re: wheel and brake wobble
Post by: tigers_gonads on 02 December 2014, 08:32:50
no lips on discs as they are new,,,,,,they were changed because of this problem but it remains....however will tell him to check the the new discs just in case   thanks   :y :y


Just for reference, I drove my shed for 6 months on knackered front discs (large ridge / corrosion causing heavy vibration when braking hard / brakes quite hot)

Changed the discs and pads for genuine parts last month because of these symptoms but the fault remained.
Noticed that the tracking was slightly out but I was not to worried as I would need replacement tyres soon and I wanted to replace the shocks all around anyway (when funds allow)
I noticed last week the tracking was getting worse so popped into the local tyre place for a tracking check on the understanding that I could get under there with a bar first to see if they was and play in any joints.
Checked the joints, no problem.
Jacked it up and checked for wobble on the wheel.
Put it this way, I have big gonads when it comes to most things but I drove the car home at 15 mph with the hazards on and parked up.
The car hasn't move since  ;)

Oh yeh, It went through a MOT during the 1st week of September  :(

Basically, the wheel went from "a little vibration when braking heavy / hot" too "a totally collapsed bearing" in about 3 weeks  ;) ;)
Title: Re: wheel and brake wobble
Post by: terry paget on 02 December 2014, 08:38:46
What are the rear discs like?
Title: Re: wheel and brake wobble
Post by: flyer 0712 on 02 December 2014, 10:27:24
To be honest the rear discs and pads look to be ok with no lips on discs and pads half worn,,but did not check them for being warped...thats next on his list now, :y
Title: Re: wheel and brake wobble
Post by: chrisgixer on 02 December 2014, 11:41:11
If the discs where warped, or incorrectly seated, or out of true in any way,  you'd feel inconsistent brake force the slower the speed when braking. So in effect you'd be nodding your head as you pull up at the lights etc.
Title: Re: wheel and brake wobble
Post by: Field Marshal Dr. Opti on 02 December 2014, 12:36:34
If the discs where warped, or incorrectly seated, or out of true in any way,  you'd feel inconsistent brake force the slower the speed when braking. So in effect you'd be nodding your head as you pull up at the lights etc.

I may have this problem.

Front discs and pads have covered over 30,000 miles.
Title: Re: wheel and brake wobble
Post by: Entwood on 02 December 2014, 12:40:27
If the discs where warped, or incorrectly seated, or out of true in any way,  you'd feel inconsistent brake force the slower the speed when braking. So in effect you'd be nodding your head as you pull up at the lights etc.

I may have this problem.

Front discs and pads have covered over 30,000 miles.

Brakes very, very rarely "warp" ... think of it .. the disc is pretty thick and robust ... just how does it warp so easily as people make out ??

The answer .. it doesn't !

http://www.powerbrake.co.za/tech_info/tech_01_judder.htm

http://www.powerbrake.co.za/tech_info/tech_03_warping.htm

:)
Title: Re: wheel and brake wobble
Post by: 05omegav6 on 02 December 2014, 12:55:39
Not allowing for heat dissipation, or lack of, holding the brakes on after working them hard... ::)
Title: Re: wheel and brake wobble
Post by: Entwood on 02 December 2014, 14:01:31
Not allowing for heat dissipation, or lack of, holding the brakes on after working them hard... ::)

yup ... primary causes of DTV .. not warping ...  blame Cementite ....  :)
Title: Re: wheel and brake wobble
Post by: Andy B on 02 December 2014, 18:36:35
Not allowing for heat dissipation, or lack of, holding the brakes on after working them hard... ::)

and using cheap pattern discs  ::)
Title: Re: wheel and brake wobble
Post by: Field Marshal Dr. Opti on 02 December 2014, 18:46:40
Not allowing for heat dissipation, or lack of, holding the brakes on after working them hard... ::)

and using cheap pattern discs  ::)

I hope my replacement £88 Pagid discs and pads come come under this description?.. :-\
Title: Re: wheel and brake wobble
Post by: Andy B on 02 December 2014, 19:09:29
Not allowing for heat dissipation, or lack of, holding the brakes on after working them hard... ::)

and using cheap pattern discs  ::)

I hope my replacement £88 Pagid discs and pads come come under this description?.. :-\

the cheap pattern discs for the front of my Senator 24 valve were included  >:(
Title: Re: wheel and brake wobble
Post by: 05omegav6 on 02 December 2014, 19:24:58
Not allowing for heat dissipation, or lack of, holding the brakes on after working them hard... ::)

and using cheap pattern discs  ::)
Whatever Devon and Cornwall Constabulary had endowed it with before I bought it ::)
Title: Re: wheel and brake wobble
Post by: flyer 0712 on 02 December 2014, 19:55:14
That write up is very interesting reading....what appears to be a simple subject...brake judder....turns out to be a very deep and complicated issue...However  after reading the explanation that has been posted,it does help to not only disperse (old wives tales ) but also to under stand the issue properly,, :y :y
Title: Re: wheel and brake wobble
Post by: Seth on 03 December 2014, 12:10:43
Not allowing for heat dissipation, or lack of, holding the brakes on after working them hard... ::)

'Cadence braking' ... as practised by train drivers 8)
Title: Re: wheel and brake wobble
Post by: flyer 0712 on 03 December 2014, 16:30:42
Cheers Seth...understood now  :y