Brakes replaced- questions!

SiD the Turtle

SiD the Turtle

SiD the Turtle

Soldato
Joined
16 Nov 2003
Posts
9,682
Location
On the pale blue dot
Hi folks,

The front discs on my mk2 Focus were worn down to their limit, so I had both the front discs and the brake pads replaced the other day. I've done about 300 miles on them and they look like the picture at the bottom of my post now. This is the first time I've had them swapped out on this car and I've got a few questions:

  • Why is the brake pad a wedge shape?
  • When rolling at low speed, there's a whining coming from one of the brakes, from the picture below, I suspect the brake is slightly touching the disc when I'm not touching the brake. Could that be the cause?

jOtRkV8l.jpg
 
Looks like the pad isn't really bedded in much at all there, would expect full contact after 300 miles. Do some firm braking to help it on it's way.
If the pads are very tight in the calliper then it could stop it from returning properly, filing the edge of the pad will help this but don't go too far or it will be too loose and rattle for ever more.
 
The pad should be making uniform contact with the disc. It looks like it hasn't been fitted correctly which is why you're getting whine from that corner. I'd advise AGAINST the 'hard braking' as you'll only make the pad thinner at one side which can lead to problems later. Go back and ask them to check it.

If it's binding it'll pull in that direction. Find a flat, quiet road and while doing maybe 20MPH take your hands off the wheel. If it's binding the car will pull in that direction. Have you also noticed a decrease in MPG as this will happen with a binding pad.

As you can see here (and any other image you can find of a brake pad) the pad is flat to ensure maximum and uniform contact with the disc.

http://s.hswstatic.com/gif/brake-pads-1.jpg
 
Last edited:
Brakes have been fitted perfectly fine, apart from a lack of any grease to be seen from that angle at least..

As said in the first reply, those pads are meant to look like that, they are not perfectly flat. The noise could possibly be the backing plate rubbing against the disc, quick easy to knock when doing brakes and easy enough to push back.

I would do another couple of hundred miles and see if the noise gets any better at all, if not take it back to where you had them done and ask them to have a look.

But until then, the brakes are fitted perfectly fine from what can be seen there, so it is perfectly safe.
 
It looks like only the inner part of the disc has been worn smooth or had any contact with the pad, yet they're been fitted 'perfectly fine'? Not sure if it's just the shadow but it also looks like there's more space between the pad and disc under the calliper and less toward the centre of the disc which there shouldn't be?
 
whats the other side look like?

Is that pad wedge shaped all the way through? or does it flatten out further in?
 
Last edited:
MissChief said:
It looks like only the inner part of the disc has been worn smooth or had any contact with the pad, yet they're been fitted 'perfectly fine'? Not sure if it's just the shadow but it also looks like there's more space between the pad and disc under the calliper and less toward the centre of the disc which there shouldn't be?
Click to expand...

As per the first reply, pads tend to have a chamfered edge on the flat surface that wears away. From memory I'd expect it to have the majority of the pad contacting with the disc, but it would be really difficult to actually fit them incorrectly anyway, the forces put on the pad would snap them back into place properly under normal use, so long as they are actually the right pads.

It's usually also tight enough putting a caliper back on with new pads when sitting flush, if they were angled incorrectly it would be pretty obvious when fitting
 
Last edited:
You must log in or register to reply here.
Back
Top Bottom