I have a puzzling problem I have a vibration through the steering wheel on light pressure on the brake pedal and I can't find the problem. Before the obvious is stated warped discs yes I would say the same but what would cause this I have changed the discs 3 times as they keep warping. I have changed the calipers and the hoses also been right through the suspension new shocks arms and ball joints just incase something else was worn causing the vibration can't find anything. So my question is why do they keep warping under normal braking I would like to sort it as I like the car. Anything more than light pressure all steering wheel vibration disappears.
quote:
Originally posted by bug1
I have a puzzling problem I have a vibration through the steering wheel on light pressure on the brake pedal and I can't find the problem. Before the obvious is stated warped discs yes I would say the same but what would cause this I have changed the discs 3 times as they keep warping. I have changed the calipers and the hoses also been right through the suspension new shocks arms and ball joints just incase something else was worn causing the vibration can't find anything. So my question is why do they keep warping under normal braking I would like to sort it as I like the car. Anything more than light pressure all steering wheel vibration disappears.
Did you clean all trace of rust/dirt of the hub flanges before fitting the discs? It's the most common cause of brake vibration and often diagnosed as "warped discs"
Yes all slide pins cleaned and lubricated and hub faces cleaned when discs first changed brakes are perfect on each set of discs it's only after a couple of hundred of miles it comes back hence I am now lost.
you said you changed the discs 3 times as they kept warping,what brand are they ?some of the cheap ones made in India a rubbish,have you tried
Eurocarparts,they sell OE ones for small money.
The disc brands are mintex national from motor parts direct and Bendix who are by Honeywell and the do aircraft brakes.
Warped disc are often mistaken for buildup on the discs caused by lots of gentle braking with today's pads, you need to aggressively brake occasionally to keep things clean or try more aggressive pads.
discs have done less than a thousand miles.
Different pads are the solution more abrasive pads are required to keep the discs free from deposits.
I know rear pads with an abrasive break in layer are made forsome BMW.
Did you check the discs with a DTI when they'd been fitted ?
Worth borrowing one to check, at least then you can cross this one of the list of possible causes
yes all checked
What tyres are fitted ? X3's are uber sensitive to tyres, I've experienced weird clunks, bangs and shudders due to them.
I had one in with a vibration at 30mph, brand new budget tyres were the problem. Fitted Dunlops as pr BMW spec and
it drove faultlessly.
quote:
Originally posted by bug1
discs have done less than a thousand miles.
They need bedding in from day 1, if you look at the disc does it look like the pad has been biting into it?
Either way bomb down the road and some hard applications from speed to get some heat into things as described further above
quote:
Originally posted by mark chandler
They need bedding in from day 1, if you look at the disc does it look like the pad has been biting into it?
Either way bomb down the road and some hard applications from speed to get some heat into things as described further above
Also - is it an auto?
quote:
Originally posted by gregs
Also - is it an auto?
Firstly the tyres are bmw spec and all the same tread depth approx 7mm it's not an auto and have given the brakes a good pasting today. They look like they have bedded in but after they were treated like has been suggested and they just appear to be no better.
Re-check wheel balance ? - even swap front to back to look for a difference?
Saw a Disc warped myth mentioned in a previous post
http://www.locostbuilders.co.uk/viewthread.php?tid=199787
Worth a read.
I had similar issues with my Volvo. It had several front discs and sets of pads. Eventually I fitted genuine Volvo pads and it fixed it.
The hub where cleaned properly and I have changed at least fifty sets of dics and never had a problem before what I find odd is when first changed brakes were perfect I am not a hard on the brakes but in the same breath I am not light on the pedal all the main suspension components have been changed and ball joints and anti roll bar bushes and link rods so this is why I am lost.