Dave_A

Hi folks,

I've stripped my brakes down this weekend having been suffering from the pulsing brake pedal that comes with having warped discs. I couldn't find any indication of the disc being warped, but did find that the inner pad on the nearside was disintigrating slightly with a definite groove being worn into it near the hub. The central groove was full of packed down brake particles.

I cleaned out the groove and put it all back together, and the pulsing pedal feeling has gone. The question is, why is the pad becoming worn and clogging the central groove. The offside inner pad was similar but not as clogged.

I've done a write up with photos here - www.scoobyphotos.com/brakes_jan05.html - if you could have a read and see what you think....

anyone got any suggestions?

Cheers
Dave

3barboost

When was the last time the pads were changed ? and fluid ? and how hard do you drive ?

It almost looks like those pads are not 100 % bedded in

The other potential is / was how secure are your calipers ? that pulsing feeling may have had nothing to do with the dirt in the pad groove but maybe loose calipers ?, loose calipers would also explain the "non uniform" look to the pads, this is a thought and intepretation from 10k miles away

Dave_A

Hi, pads and discs were put on the car in october last year, so 4 months ago. Covered around 2000 miles since then. Don't drive particularly hard, and certainly not a driver who stands on the brakes very often.

Calipers seemed to be good and tight when I checked them yesterday, as it was one of the things that crossed my mind as I was stripping them down.

Dave

Dave_A

*bump*

the warped feeling has returned, still wondering whats caused the uneven wear of the pads - may not be related to warped discs, but I can't understand why the pads would wear in the way they have.

Dave

willy

Give the brakes some more stick...
I rememeber Skip Brown (Pug specialist)used to clean off the pad material from the disc with emery paper at service time.

I reckon you could have pad material build up on the discs/ glazed pads.
I would take the pads off, rub them with emery to de-glaze them and also deglaze the discs in the same way.

I dont seem to have that problem , but then you know how I use my brakes...

Hope this helps

*****

BrynO

I read an article recently on the causes of warped disks and it was saying disks don't often warp, it is like ***** says an uneven build up of fused pad material which casues excessive run out, giving the feeling of a wonky disk. One of causes was said to be sitting with brake pedal on with hot brakes, this transfers material from pad to disk. Did say don't use emery paper to clean them though (can't recall why now) although I have done this myself in the past.. some enthusiastic use of the brakes may help clear the disks off..

Dave_A

Thanks guys, I did try giving the brakes a bit of welly last week to try and clear any loose material off them, but no joy really. I've had a look at the inside of the disks today and it looks like theres a 10mm groove been worn into the edge of the disk nearest the hub. Almost like theres been something trapped between the pad and the disk and worn a groove into both. It seems to have happened on both sides of the car as well. Very strange. Going to get it checked out when I get back from holiday. Unfotunately its made driving the car an unenjoyable experience!

Dave

3barboost

you not going to believe this, but after I replied to this thread earlier, i have picked up brake problems.....

I have a MY00 with AP 4 pots and on the passenger front side, I have an area closest to the hub, that over heats as it has a "blue glaze" look to it, and I now have a pulsing brake pedal, top suspect is
a) sticking piston in the caliper or
b) wheel bearing,

the wheel bearing gets my vote !!!!! as it could be allowing play and therefore allowing the disc and pad to make contact, the warped feeling will come from the wheel being knocked off its course and "wobbling" a bit

Car can only be seen by specialist on this coming Thursday so news then

RON

I would have thought that a wheel bearing going would mean that the outer edge of the inner pad would be the bit that rubbed all the time, surely the inner edge wouldn't be touching the pad......

Dave_A

let me know how you get on, mines booked into scoobyclinic to be looked over shortly, be good to know what cost I could be in for...

Dave

King Eric

3bar boost...

My money on your problem is exactly what you suggest, a wheel bearing

I had the very self same problem you are displaying. New wheel bearing sorted everything

Dave_A

How much does a new wheel bearing come in at these days?

Dave